TECHNICAL FIELD
[001] The subject matter described herein in general relates to the field of cosmetic and soap industry, and in particular, relates to the field of quality and assurance in the soap industry. 5
BACKGROUND OF INVENTION
[002] Estimation of total fatty matter is an essential step in industries that cater to mass production of soap bars. The process for the same is not straight-forward, as there are various kind of soaps (syndet bars, soaps containing fatty acids, combi-bars
10 comprising both fatty acids and surfactants, detergent bars, floating bars etc.), and
country specific standards that need to be essentially complied before marketing the particular soap product.
[003] Some of the newer methods known and available in the market for detecting total fatty acid content use specific analytical tools such as gas phase
15 chromatography, high performance liquid chromatography and colorimetry. Gas
chromatography is commonly conducted by using an organic solvent mixed solution of sulfuric acid treatment sample, and in the high-temperature by using an organic solvent extraction of fatty acid, followed by gas-phase chromatographic analysis. High performance liquid chromatography, is typically conducted by using an organic
20 solvent extraction of fatty acid in the sample, followed by high performance liquid
chromatography analysis. Colormetric method mainly adopts the organic solvent extraction of fatty acid in a sample, in order to determine its content. However, the above methods have the following shortcomings: a) chromatographic techniques require complicated extraction and fluid ingredients, as well as suffer from relatively
25 long detection process, high costs, expensive instrument; b) the colorimetric
techniques use complex components of the reagent and suffer from poor reproducibility of result.
[004] CN201610022806 discloses a free fatty acid content measuring reagent kit and method thereof. CN104678107A discloses a method, reagent and kit for
30 quantitatively detecting free fatty acid. However, the kits mention costly ingredients
2

and complicated protocol for testing. JP03002563A on the other hand discloses an automatic analyzer that would be expensive to manufacture.
[005] Though several fatty acid estimation methods are available in country
specific stands, such as, Indian standard (IS) 13498, but there is always a need for
5 improved methods that are less time consuming, provide equivalent or more sensitive
test results and are easy to conduct (without specific technical requirement or equipment).
SUMMARY OF THE INVENTION
[006] In an aspect of the present invention, there is provided an efficient process
10 for determination of total fatty matter in soap, said process comprising the steps of:
a) obtaining a soap; b) contacting the soap with water to obtain a first mixture; c) contacting a first portion of the first mixture with at least one solvent, at least one indicator, and chloroform to obtain a second mixture; d) titrating the second mixture with at least one titrant that changes color at a first end point; e) recording the amount
15 of the at least one titrant added to the second mixture to obtain a first volume; f)
contacting a second portion of the first mixture with at least one indicator, chloroform and at least one acid to obtain a third mixture; g) titrating the third mixture with at least one titrant that changes color at a second end point; h) recording the amount of the at least one titrant added to the third mixture to obtain a second
20 volume; and i) determining total fatty matter in the soap by using the first, and the
second volume, wherein the process is carried out within a period in the range of 30 – 35 min.
[007] These and other features, aspects, and advantages of the present subject matter will be better understood with reference to the following description and
25 appended claims. This summary is provided to introduce a selection of concepts in a
simplified form. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
DETAILED DESCRIPTION OF THE INVENTION
3

[008] Those skilled in the art will be aware that the present disclosure is subject to
variations and modifications other than those specifically described. It is to be
understood that the present disclosure includes all such variations and modifications.
The disclosure also includes all such steps, features, compositions, and compounds
5 referred to or indicated in this specification, individually or collectively, and any and
all combinations of any or more of such steps or features. Definitions
[009] For convenience, before further description of the present disclosure, certain terms employed in the specification, and examples are delineated here. These
10 definitions should be read in the light of the remainder of the disclosure and
understood as by a person of skill in the art. The terms used herein have the meanings recognized and known to those of skill in the art, however, for convenience and completeness, particular terms and their meanings are set forth below. [0010] The articles “a”, “an” and “the” are used to refer to one or to more than one
15 (i.e., to at least one) of the grammatical object of the article.
[0011] The terms “comprise” and “comprising” are used in the inclusive, open sense, meaning that additional elements may be included. It is not intended to be construed as “consists of only”. [0012] Throughout this specification, unless the context requires otherwise the word
20 “comprise”, and variations such as “comprises” and “comprising”, will be
understood to imply the inclusion of a stated element or step or group of element or steps but not the exclusion of any other element or step or group of element or steps. [0013] The term “including” is used to mean “including but not limited to”. “Including” and “including but not limited to” are used interchangeably.
25 [0014] Ratios, concentrations, amounts, and other numerical data may be presented
herein in a range format. It is to be understood that such range format is used merely for convenience and brevity and should be interpreted flexibly to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as
30 if each numerical value and sub-range is explicitly recited. For example, a
temperature ranges of about 100-125 ℃ should be interpreted to include not only the
4

explicitly recited limits of about 100 ℃ to about 125 ℃, but also to include sub¬ranges, such as 100-105 ℃, 103-123 ℃, and so forth, as well as individual amounts, including fractional amounts, within the specified ranges, such as 100.2 ℃, and 123.5 ℃, for example. 5 [0015] The term “at least one” is used to mean one or more and thus includes individual components as well as mixtures/combinations.
[0016] For the purposes of the present disclosure, the term end point is to be understood as the point at which the separation of chloroform and aqueous layers (water only or mixture of water and at least one solvent) with blue colour shift in
10 chloroform.
[0017] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the
15 disclosure, the preferred methods, and materials are now described. All publications mentioned herein are incorporated herein by reference.
[0018] The present disclosure is not to be limited in scope by the specific embodiments described herein, which are intended for the purposes of exemplification only. Functionally-equivalent products, compositions, and methods
20 are clearly within the scope of the disclosure, as described herein.
[0019] Since stringent norms have been identified by various countries on the amount of fatty content of soap, the methods for accurate estimation of the same are essential. As mentioned previously, the existing methods of determining total fatty matter in soap are both expensive and time-consuming. The present disclosure
25 attempts to address the problems by providing a two-phase titration process that is easy to carry out and utilizes cost-effective ingredients. Additionally, the present method provides suitable accuracy, while being time-efficient. The present disclosure attempts to accurately determine the fatty acid content via a simple titration-method involving a biphasic system comprising chloroform and water. The
30 present disclosure identifies benzethonium chloride as a titrant that is able to provide a color-change (blue) associated with the end point involving separation of
5

chloroform and aqueous layers with blue colour shift in the chloroform phase. The volume of said titrant (having known concentration) is established. Furthermore, in the second step acidification of soap solution allows accurate determination of the interference due to surfactant. This volume can be easily subtracted from the above 5 volume to obtain an accurate fatty acid content (devoid of surfactant) as described herein.
[0020] In an embodiment of the present invention, there is provided an efficient process for determination of total fatty matter in soap, said process comprising the steps of: a) obtaining a soap; b) contacting the soap with water to obtain a first
10 mixture; c) contacting a first portion of the first mixture with at least one solvent, at least one indicator, and chloroform to obtain a second mixture; d) titrating the second mixture with at least one titrant that changes color at a first end point; e) recording the amount of the at least one titrant added to the second mixture to obtain a first volume; f) contacting a second portion of the first mixture with at least one indicator,
15 chloroform and at least one acid to obtain a third mixture; g) titrating the third mixture with at least one titrant that changes color at a second end point; h) recording the amount of the at least one titrant added to the third mixture to obtain a second volume; and i) determining total fatty matter in the soap by using the first, and the second volume, wherein the process is carried out within a period in the range of 30
20 - 35 min. In another embodiment of the present disclosure the process is carried out within a period in the range of 31 - 34 min.
[0021] In an embodiment of the present disclosure, there is provided an efficient process for determination of total fatty matter in soap as described herein, wherein the process is carried out in at a temperature in the range of 18 - 32 ℃. In another
25 embodiment of the present disclosure the process is carried out in at a temperature in the range of 20 - 30 ℃. In yet another embodiment of the present disclosure the process is carried out in at a temperature in the range of 21 - 29 ℃. [0022] In an embodiment of the present disclosure, there is provided an efficient process for determination of total fatty matter in soap as described herein, wherein
30 obtain a first mixture may require pre-heating at a temperature in the range of 40 -50 ℃.
6

[0023] In an embodiment of the present invention, there is provided an efficient process for determination of total fatty matter in soap, said process comprising the steps of: a) obtaining a soap; b) contacting the soap with water to obtain a first mixture; c) contacting a first portion of the first mixture with at least one solvent, at 5 least one indicator, and chloroform to obtain a second mixture; d) titrating the second mixture with at least one titrant that changes color at a first end point; e) recording the amount of the at least one titrant added to the second mixture to obtain a first volume; f) contacting a second portion of the first mixture with at least one indicator, chloroform and at least one acid to obtain a third mixture; g) titrating the third
10 mixture with at least one titrant that changes color at a second end point; h) recording the amount of the at least one titrant added to the third mixture to obtain a second volume; and i) determining total fatty matter in the soap by using the first, and the second volume, wherein the process is carried out within a period in the range of 30 - 35 min and the process is carried out in at a temperature in the range of 18 - 32 ℃.
15 [0024] In an embodiment of the present disclosure, there is provided an efficient process for determination of total fatty matter in soap as described herein, wherein the total fatty matter of soap comprises a salt of at least one alkali metal and a mixture of C8-C20 fatty acids. [0025] In an embodiment of the present invention, there is provided an efficient
20 process for determination of total fatty matter in soap, said process comprising the steps of: a) obtaining a soap; b) contacting the soap with water to obtain a first mixture; c) contacting a first portion of the first mixture with at least one solvent, at least one indicator, and chloroform to obtain a second mixture; d) titrating the second mixture with at least one titrant that changes color at a first end point; e) recording
25 the amount of the at least one titrant added to the second mixture to obtain a first volume; f) contacting a second portion of the first mixture with at least one indicator, chloroform and at least one acid to obtain a third mixture; g) titrating the third mixture with at least one titrant that changes color at a second end point; h) recording the amount of the at least one titrant added to the third mixture to obtain a second
30 volume; and i) determining total fatty matter in the soap by using the first, and the second volume, wherein the process is carried out within a period in the range of 30
7

– 35 min and the total fatty matter of soap comprises a salt of at least one alkali metal and a mixture of C8-C20 fatty acids.
[0026] In an embodiment of the present disclosure, there is provided an efficient
process for determination of total fatty matter in soap as described herein, wherein
5 the soap further comprises at least one surfactant.
[0027] In an embodiment of the present invention, there is provided an efficient process for determination of total fatty matter in soap, said process comprising the steps of: a) obtaining a soap; b) contacting the soap with water to obtain a first mixture; c) contacting a first portion of the first mixture with at least one solvent, at
10 least one indicator, and chloroform to obtain a second mixture; d) titrating the second
mixture with at least one titrant that changes color at a first end point; e) recording the amount of the at least one titrant added to the second mixture to obtain a first volume; f) contacting a second portion of the first mixture with at least one indicator, chloroform and at least one acid to obtain a third mixture; g) titrating the third
15 mixture with at least one titrant that changes color at a second end point; h) recording
the amount of the at least one titrant added to the third mixture to obtain a second volume; and i) determining total fatty matter in the soap by using the first, and the second volume, wherein the process is carried out within a period in the range of 30 – 35 min and the soap further comprises at least one surfactant.
20 [0028] In an embodiment of the present disclosure, there is provided an efficient
process for determination of total fatty matter in soap as described herein, wherein the surfactant is selected from the group consisting of alpha olefin sulfonates, sodium lauryl ether sulfate, and combinations thereof. In another embodiment of the present disclosure the surfactant is alpha olefin sulfonate. In yet another embodiment of the
25 present disclosure the surfactant is sodium lauryl ether sulfate. In an alternative
embodiment of the present disclosure the surfactant is a combination of alpha olefin sulfonate and sodium lauryl ether sulfate. For the purposes of the present disclosure it is construed that other commonly used surfactants in the soap industry are applicable.
30 [0029] In an embodiment of the present disclosure, there is provided an efficient
process for determination of total fatty matter in soap as described herein, wherein
8

the at least one titrant is selected from the group consisting of benzethonium chloride,
cetyltrimethylammonium bromide (CTAB), cetrimmonium chloride (CTAC), and
combinations thereof. In another embodiment of the present disclosure the at least
one titrant is benzethonium chloride.
5 [0030] In an embodiment of the present invention, there is provided an efficient
process for determination of total fatty matter in soap, said process comprising the steps of: a) obtaining a soap; b) contacting the soap with water to obtain a first mixture; c) contacting a first portion of the first mixture with at least one solvent, at least one indicator, and chloroform to obtain a second mixture; d) titrating the second
10 mixture with at least one titrant that changes color at a first end point; e) recording
the amount of the at least one titrant added to the second mixture to obtain a first volume; f) contacting a second portion of the first mixture with at least one indicator, chloroform and at least one acid to obtain a third mixture; g) titrating the third mixture with at least one titrant that changes color at a second end point; h) recording
15 the amount of the at least one titrant added to the third mixture to obtain a second
volume; and i) determining total fatty matter in the soap by using the first, and the second volume, wherein the process is carried out within a period in the range of 30 – 35 min and the at least one titrant is selected from the group consisting of benzethonium chloride, cetyltrimethylammonium bromide (CTAB), cetrimmonium
20 chloride (CTAC), and combinations thereof.
[0031] In an embodiment of the present invention, there is provided an efficient process for determination of total fatty matter in soap, said process comprising the steps of: a) obtaining a soap; b) contacting the soap with water to obtain a first mixture; c) contacting a first portion of the first mixture with at least one solvent, at
25 least one indicator, and chloroform to obtain a second mixture; d) titrating the second
mixture with benzethonium chloride that changes color at a first end point; e) recording the amount of the benzethonium chloride added to second mixture to obtain a first volume; f) contacting a second portion of the first mixture with at least one indicator, chloroform and at least one acid to obtain a third mixture; g) titrating
30 the third mixture with benzethonium chloride that changes color at a second end
point; h) recording the amount of the benzethonium chloride added to third mixture
9

to obtain a second volume; and i) determining total fatty matter in the soap by using the first, and the second volume, wherein the process is carried out within a period in the range of 30 – 35 min.
[0032] In an embodiment of the present disclosure, there is provided an efficient
5 process for determination of total fatty matter in soap as described herein, wherein
the at least one solvent is selected from the group consisting of water-ethanol mixture, ethanol, isopropanol, methanol, and combinations thereof. In yet another embodiment of the present disclosure the at least one solvent is ethanol. In yet another embodiment of the present disclosure the at least one solvent is water-ethanol
10 mixture having the vol/vol ratio of 1:1.
[0033] In an embodiment of the present disclosure, there is provided an efficient process for determination of total fatty matter in soap as described herein, wherein the at least one indicator is selected from the group consisting of xylene cyanol FF, disulfine blue, and combinations thereof. In another embodiment of the present
15 disclosure the at least one indicator is xylene cyanol FF. In yet another embodiment
of the present disclosure the at least one indicator is disulfine blue.
[0034] In an embodiment of the present invention, there is provided an efficient process for determination of total fatty matter in soap, said process comprising the steps of: a) obtaining a soap; b) contacting the soap with water to obtain a first
20 mixture; c) contacting a first portion of the first mixture with at least one solvent, at
least one indicator, and chloroform to obtain a second mixture; d) titrating the second mixture with at least one titrant that changes color at a first end point; e) recording the amount of the at least one titrant added to the second mixture to obtain a first volume; f) contacting a second portion of the first mixture with at least one indicator,
25 chloroform and at least one acid to obtain a third mixture; g) titrating the third
mixture with at least one titrant that changes color at a second end point; h) recording the amount of the at least one titrant added to the third mixture to obtain a second volume; and i) determining total fatty matter in the soap by using the first, and the second volume, wherein the process is carried out within a period in the range of 30
30 – 35 min and the at least one indicator is selected from the group consisting of xylene
cyanol FF, disulfine blue, and combinations thereof.
10

[0035] In an embodiment of the present invention, there is provided an efficient
process for determination of total fatty matter in soap, said process comprising the
steps of: a) obtaining a soap; b) contacting the soap with water to obtain a first
mixture; c) contacting a first portion of the first mixture with at least one solvent,
5 xylene cyanol FF, and chloroform to obtain a second mixture; d) titrating the second
mixture with at least one titrant that changes color at a first end point; e) recording the amount of the at least one titrant added to the second mixture to obtain a first volume; f) contacting a second portion of the first mixture with xylene cyanol FF, chloroform and at least one acid to obtain a third mixture; g) titrating the third
10 mixture with at least one titrant that changes color at a second end point; h) recording
the amount of the at least one titrant added to the third mixture to obtain a second volume; and i) determining total fatty matter in the soap by using the first, and the second volume, wherein the process is carried out within a period in the range of 30 – 35 min.
15 [0036] In an embodiment of the present disclosure, there is provided an efficient
process for determination of total fatty matter in soap as described herein, wherein the at least one acid is selected from the group consisting of sulfuric acid, hydrochloric acid, and combinations thereof. In another embodiment of the present disclosure the at least one acid is sulfuric acid. In another embodiment of the present
20 disclosure the at least one acid is hydrochloric acid.
[0037] In an embodiment of the present invention, there is provided an efficient process for determination of total fatty matter in soap, said process comprising the steps of: a) obtaining a soap; b) contacting the soap with water to obtain a first mixture; c) contacting a first portion of the first mixture with at least one solvent, at
25 least one indicator, and chloroform to obtain a second mixture; d) titrating the second
mixture with at least one titrant that changes color at a first end point; e) recording the amount of the at least one titrant added to the second mixture to obtain a first volume; f) contacting a second portion of the first mixture with at least one indicator, chloroform and at least one acid to obtain a third mixture; g) titrating the third
30 mixture with at least one titrant that changes color at a second end point; h) recording
the amount of the at least one titrant added to the third mixture to obtain a second
11

volume; and i) determining total fatty matter in the soap by using the first, and the
second volume, wherein the process is carried out within a period in the range of 30
– 35 min and the at least one acid is selected from the group consisting of sulfuric
acid, hydrochloric acid, and combinations thereof.
5 [0038] In an embodiment of the present invention, there is provided an efficient
process for determination of total fatty matter in soap, said process comprising the steps of: a) obtaining a soap; b) contacting the soap with water to obtain a first mixture; c) contacting a first portion of the first mixture with at least one solvent, at least one indicator, and chloroform to obtain a second mixture; d) titrating the second
10 mixture with at least one titrant that changes color at a first end point; e) recording
the amount of the at least one titrant added to the second mixture to obtain a first volume; f) contacting a second portion of the first mixture with at least one indicator, chloroform and sulfuric acid to obtain a third mixture; g) titrating the third mixture with at least one titrant that changes color at a second end point; h) recording the
15 amount of the at least one titrant added to the third mixture to obtain a second
volume; and i) determining total fatty matter in the soap by using the first, and the second volume, wherein the process is carried out within a period in the range of 30 – 35 min. [0039] In an embodiment of the present disclosure, there is provided an efficient
20 process for determination of total fatty matter in soap as described herein, wherein
the at least one indicator present in the second mixture has a concentration in the range of 8.35 x 10-5 – 10.21 x 10-5 M. In another embodiment of the present disclosure the at least one indicator present in the second mixture has a concentration in the range of 8.65 x 10-5 – 10.0 x 10-5 M.
25 [0040] In an embodiment of the present invention, there is provided an efficient
process for determination of total fatty matter in soap, said process comprising the steps of: a) obtaining a soap; b) contacting the soap with water to obtain a first mixture; c) contacting a first portion of the first mixture with at least one solvent, at least one indicator, and chloroform to obtain a second mixture; d) titrating the second
30 mixture with at least one titrant that changes color at a first end point; e) recording
the amount of the at least one titrant added to the second mixture to obtain a first
12

volume; f) contacting a second portion of the first mixture with at least one indicator,
chloroform and at least one acid to obtain a third mixture; g) titrating the third
mixture with at least one titrant that changes color at a second end point; h) recording
the amount of the at least one titrant added to the third mixture to obtain a second
5 volume; and i) determining total fatty matter in the soap by using the first, and the
second volume, wherein the process is carried out within a period in the range of 30 – 35 min and the at least one indicator present in the second mixture has a concentration in the range of 8.35 x 10-5 – 10.21 x 10-5 M.
[0041] In an embodiment of the present disclosure, there is provided an efficient
10 process for determination of total fatty matter in soap as described herein, wherein
the at least one indicator present in the third mixture has a concentration in the range of 16.71 x 10-5 – 20.42 x 10-5 M. In another embodiment of the present disclosure the at least one indicator present in the third mixture has a concentration in the range of 16.00 x 10-5 – 20.00 x 10-5 M.
15 [0042] In an embodiment of the present invention, there is provided an efficient
process for determination of total fatty matter in soap, said process comprising the steps of: a) obtaining a soap; b) contacting the soap with water to obtain a first mixture; c) contacting a first portion of the first mixture with at least one solvent, at least one indicator, and chloroform to obtain a second mixture; d) titrating the second
20 mixture with at least one titrant that changes color at a first end point; e) recording
the amount of the at least one titrant added to the second mixture to obtain a first volume; f) contacting a second portion of the first mixture with at least one indicator, chloroform and at least one acid to obtain a third mixture; g) titrating the third mixture with at least one titrant that changes color at a second end point; h) recording
25 the amount of the at least one titrant added to the third mixture to obtain a second
volume; and i) determining total fatty matter in the soap by using the first, and the second volume, wherein the process is carried out within a period in the range of 30 – 35 min and the at least one indicator present in the third mixture has a concentration in the range of 16.71 x 10-5 – 20.42 x 10-5 M..
30 [0043] In an embodiment of the present disclosure, there is provided an efficient
process for determination of total fatty matter in soap as described herein, wherein
13

the at least one solvent to the chloroform present in the second mixture has a weight
ratio in the range of 1:0.8 – 1:1.1. In another embodiment of the present disclosure
the at least one solvent to the chloroform present in the second mixture has a weight
ratio in the range of 1:0.85 – 1:1.05. In yet another embodiment of the present
5 disclosure the at least one solvent to the chloroform present in the second mixture
has a weight ratio in the range of 1:0.9 – 1:1.0.
[0044] In an embodiment of the present invention, there is provided an efficient process for determination of total fatty matter in soap, said process comprising the steps of: a) obtaining a soap; b) contacting the soap with water to obtain a first
10 mixture; c) contacting a first portion of the first mixture with at least one solvent, at
least one indicator, and chloroform to obtain a second mixture; d) titrating the second mixture with at least one titrant that changes color at a first end point; e) recording the amount of the at least one titrant added to the second mixture to obtain a first volume; f) contacting a second portion of the first mixture with at least one indicator,
15 chloroform and at least one acid to obtain a third mixture; g) titrating the third
mixture with at least one titrant that changes color at a second end point; h) recording the amount of the at least one titrant added to the third mixture to obtain a second volume; and i) determining total fatty matter in the soap by using the first, and the second volume, wherein the process is carried out within a period in the range of 30
20 – 35 min and the at least one solvent to the chloroform present in the second mixture
has a weight ratio in the range of 1:0.8 – 1:1.1.
[0045] In an embodiment of the present disclosure, there is provided an efficient process for determination of total fatty matter in soap as described herein, wherein the third mixture has at least one acid in the range of 0.03 –0.05 M. In another
25 embodiment of the present disclosure the third mixture has at least one acid in the
range of 0.035 –0.045 M. In another embodiment of the present disclosure the third mixture has at least one acid in the range of 0.035 –0.045 M.
[0046] In an embodiment of the present invention, there is provided an efficient process for determination of total fatty matter in soap, said process comprising the
30 steps of: a) obtaining a soap; b) contacting the soap with water to obtain a first
mixture; c) contacting a first portion of the first mixture with at least one solvent, at
14

least one indicator, and chloroform to obtain a second mixture; d) titrating the second
mixture with at least one titrant that changes color at a first end point; e) recording
the amount of the at least one titrant added to the second mixture to obtain a first
volume; f) contacting a second portion of the first mixture with at least one indicator,
5 chloroform and at least one acid to obtain a third mixture; g) titrating the third
mixture with at least one titrant that changes color at a second end point; h) recording the amount of the at least one titrant added to the third mixture to obtain a second volume; and i) determining total fatty matter in the soap by using the first, and the second volume, wherein the process is carried out within a period in the range of 30
10 – 35 min and the third mixture has at least one acid in the range of 0.03 –0.05 M.
[0047] In an embodiment of the present disclosure, there is provided an efficient process for determination of total fatty matter in soap as described herein, wherein the second mixture has a pH in the range of 9.5 – 9.7. In another embodiment of the present disclosure the second mixture has a pH in the range of 9.55 – 9.65.
15 [0048] In an embodiment of the present invention, there is provided an efficient
process for determination of total fatty matter in soap, said process comprising the steps of: a) obtaining a soap; b) contacting the soap with water to obtain a first mixture; c) contacting a first portion of the first mixture with at least one solvent, at least one indicator, and chloroform to obtain a second mixture; d) titrating the second
20 mixture with at least one titrant that changes color at a first end point; e) recording
the amount of the at least one titrant added to the second mixture to obtain a first volume; f) contacting a second portion of the first mixture with at least one indicator, chloroform and at least one acid to obtain a third mixture; g) titrating the third mixture with at least one titrant that changes color at a second end point; h) recording
25 the amount of the at least one titrant added to the third mixture to obtain a second
volume; and i) determining total fatty matter in the soap by using the first, and the second volume, wherein the process is carried out within a period in the range of 30 – 35 min and the second mixture has a pH in the range of 9.5 – 9.7. [0049] In an embodiment of the present disclosure, there is provided an efficient
30 process for determination of total fatty matter in soap as described herein, wherein
the third mixture has a pH in the range of 0.6 – 0.9. In another embodiment of the
15

present disclosure the third mixture has a pH in the range of 0.65 – 0.85. In yet another embodiment of the present disclosure the third mixture has a pH in the range of 0.7 – 0.8.
[0050] In an embodiment of the present invention, there is provided an efficient
5 process for determination of total fatty matter in soap, said process comprising the
steps of: a) obtaining a soap; b) contacting the soap with water to obtain a first mixture; c) contacting a first portion of the first mixture with at least one solvent, at least one indicator, and chloroform to obtain a second mixture; d) titrating the second mixture with at least one titrant that changes color at a first end point; e) recording
10 the amount of the at least one titrant added to the second mixture to obtain a first
volume; f) contacting a second portion of the first mixture with at least one indicator, chloroform and at least one acid to obtain a third mixture; g) titrating the third mixture with at least one titrant that changes color at a second end point; h) recording the amount of the at least one titrant added to the third mixture to obtain a second
15 volume; and i) determining total fatty matter in the soap by using the first, and the
second volume, wherein the process is carried out within a period in the range of 30 – 35 min and the third mixture has a pH in the range of 0.6 – 0.9.
[0051] In an embodiment of the present invention, there is provided an efficient process for determination of total fatty matter in soap, said process comprising the
20 steps of: a) obtaining a soap; b) contacting the soap with water to obtain a first
mixture; c) contacting a first portion of the first mixture with at least one solvent, at least one indicator, and chloroform to obtain a second mixture; d) titrating the second mixture with at least one titrant that changes color at a first end point; e) recording the amount of the at least one titrant added to the second mixture to obtain a first
25 volume; f) contacting a second portion of the first mixture with at least one indicator,
chloroform and at least one acid to obtain a third mixture; g) titrating the third mixture with at least one titrant that changes color at a second end point; h) recording the amount of the at least one titrant added to the third mixture to obtain a second volume; and i) determining total fatty matter in the soap by using the first, and the
30 second volume, wherein the process is carried out within a period in the range of 30
16

– 35 min, the third mixture has a pH in the range of 0.6 – 0.9 and the second mixture has a pH in the range of 9.5 – 9.7.
[0052] In an embodiment of the present disclosure, there is provided an efficient
process for determination of total fatty matter in soap as described herein, wherein
5 the process allows determination of total fatty matter and the soap further comprises
surfactants. The process accurately allows determination of fatty matter while preventing interference from surfactants.
[0053] In an embodiment of the present disclosure, there is provided an efficient
process for determination of total fatty matter in soap as described herein, wherein
10 the soap is selected from the group consisting of solid soaps, such as, opaque soap
bars, transparent soap bars, combi-bars, and floating bars.
EXAMPLES
[0054] The disclosure will now be illustrated with working examples, which is
15 intended to illustrate the working of disclosure and not intended to take restrictively
to imply any limitations on the scope of the present disclosure. Unless defined
otherwise, all technical and scientific terms used herein have the same meaning as
commonly understood to one of ordinary skill in the art to which this disclosure
belongs. Although methods and materials similar or equivalent to those described
20 herein can be used in the practice of the disclosed methods and compositions, the
exemplary methods, devices and materials are described herein. It is to be understood that this disclosure is not limited to particular methods, and experimental conditions described, as such methods and conditions may apply.
[0055] The process as described herein, allows accurate determination of fatty
25 matter in soap in a short span of time. Furthermore, the process involves cheap and
non-toxic ingredients.
Example 1: General protocol for the process for determination of total fatty matter in soap using a method well known in the art (IS-13498-2017)
[0056] As per the conventional method, total fatty matter in soap samples is
30 estimated as follows:
a) 2-3 g soap sample was taken and extracted with 85 percent alcohol.
17

b) The alcohol insoluble component was discarded.
c) The alcohol soluble component was made up to 250 ml.
d) 100 ml of the sample of step c) was evaporated to 25 ml and refluxed with 50 ml of 2N sulphuric acid.
5 e) The sample of step d) was extracted with petroleum ether and washed with 1
percent sodium bicarbonate solution.
f) Petroleum ether was evaporated and the residue was weighed. The recorded weight is used to obtain total fatty matter (TFM).
The method as broadly outlined involves a high temperature extraction process
10 which typically takes 7-8 hours.
Example 2: General protocol for the process for determination of total fatty matter in soap as described in present disclosure
[0057] The method of estimation of total fatty matter (TFM) is the novel feature of the disclosure. The method comprises:
15 a) A sample of soap bar (W g) was obtained and dissolved in water to obtain soap
solution (first mixture);
b) Alcohol (at least one solvent), indicator and chloroform was added to the first portion of soap solution of step a) to obtain an alcoholic mix (second mixture) having a pH in the range of 9.5 – 9.7;
20 c) Volumetric titration on the alcoholic mix was conducted with at least one titrant-
benzethonium chloride (till end point to separation of aqueous and organic layers followed by indicator shift to chloroform phase) and the total volume of benzethonium chloride utilized was recorded– V1 in ml. d) A second portion of the soap solution was obtained;
25 e) Indicator, sulfuric acid and chloroform were added to the soap solution of step d)
to obtain sulfonated mix (third mixture) having a pH in the range of 0.6 - 0.9. f) Volumeric titration of the sulfonated mix of step e) was conducted with benzethonium chloride (till end point to separation of aqueous and organic layers followed by indicator shift to chloroform phase) and the volume of benzethonium
30 chloride used was recorded– V2 in ml
18

g) The total percentage of the fatty acid in the soap sample was calculated by the following formula: Total % of fatty acid present in soap sample =
[(V1-V2) × (Normality of benzethonium chloride) × 256] W ×10
[0058] The conventional process as described in Example 1 takes 7-8 hours for total 5 fatty matter estimation as against the method of the present disclosure (Example 2)
which was completed in 30-35 minutes. Furthermore, the method of present
disclosure is carried out at a temperature in the range of 18 - 32 °C.
Example 3- Estimation of total fatty matter in soap sample containing soap and
alpha olefin sulfonate (AOS; at least one surfactant) by using the method of the 10 present disclosure:
[0059] The process is described as follows:
a) A sample of soap bar (2 X 0.0747 g) was dissolved in 40 ml water to obtain soap
solution (first mixture) and a first portion (20 ml) containing 0.0747g of soap was
separated for further steps; 15 b) 20 ml ethanol (at least one solvent), 2.5 ml indicator (of stock- 2 mg/100 ml) and
10 ml chloroform were added to the first portion of step a) to obtain an alcoholic mix
(second mixture);
c) Volumetric titration was conducted on the alcoholic mix with at least one titrant-
benzethonium chloride (till end point to separation of aqueous and organic layers
20 followed by indicator shift to chloroform phase) and the total volume of benzethonium chloride utilized was recorded- 41.4 mL (V1 mL).
d) A second portion of the soap solution was obtained containing 0.0747g of soap;
e) 5 ml indicator (of stock- 2 mg/100 ml), 2 ml sulfuric acid (of stock- 1M) and 10 ml chloroform were added to the soap solution of step d) to obtain sulfonated mix.
25 f) Volumetric titration of the sulfonated mix of step e) was conducted with benzethonium chloride (till end point to separation of aqueous and organic layers followed by indicator shift to chloroform phase) and the volume of benzethonium chloride used was recorded - 5.0 mL (V2 mL).
g)
[(41.4-5) × (0.004)× 256]
W ×10
30 Total % of fatty acid present in soap sample =
19

= 49.89
Example 4- Estimation of total fatty matter in soap sample containing soap and AOS surfactant by using the conventional
[0060] The process is described as follows:
5 a) 2.0025 g soap sample was extracted with 85 percent alcohol.
b) The alcohol insoluble portion was discarded.
c) The alcohol soluble portion was made up to 250 ml.
d) 100 ml of sample of step c) was evaporated to 25 ml and refluxed with 50 ml of 2N sulphuric acid.
10 e) Sample of step d) was extracted with petroleum ether and washed with 1 percent
sodium bicarbonate solution
f) The petroleum ether was evaporated and the residue was weighed as TFM (M) =
0.3966.
% TFM = mass in gm of residue * 250/mass in gm of sample = 0.3966*250/2.0025
15 = 49.51.
Example 5- Estimation of total fatty matter in soap sample containing soap and sodium lauryl ether sulfate (SLES; at least one surfactant) by using the method of the present invention
[0061] The process is described as follows
20 a) A sample of soap bar (2 X 0.0753 g) was dissolved in 40 ml water to obtain soap
solution (first mixture) and a first portion (20 ml) containing 0.0753g of soap was separated for further steps;
b) 20 ml ethanol (at least one solvent), 2.5 ml indicator (of stock- 2 mg/100 ml) and
10 ml chloroform were added to the soap solution of step a) to obtain alcoholic mix
25 (second mixture);
c) Volumetric titration on the alcoholic mix was conducted with at least one titrant-
benzethonium chloride (till end point to separation of aqueous and organic layers
followed by indicator shift to chloroform phase) and the total volume of
benzethonium chloride utilized was recorded– 33.5 mL.
30 d) A second portion of the soap solution was obtained containing 0.0753g of soap;
20

e) 5 ml indicator (of stock- 2 mg/100 ml), 2 ml sulfuric acid (from stock- 1M) and
10 ml chloroform were added to the soap solution of step d) to obtain sulfonated mix.
f) Volumetric titration of the sulfonated mix of step e) was conducted with
benzethonium chloride (till end point to separation of aqueous and organic layers
5 followed by indicator shift to chloroform phase) and the volume of benzethonium
chloride used was recorded– 7.1 mL.
g) Total % of fatty acid present in soap sample=V1-(V2*0.42)*Normality of
benzethonium chloride*256/ W*10. The calculation is as follows-
33.5-(7.1*0.42)*0.004*256/0.0753*10 = 41.50.
10 Example 6- Estimation of total fatty matter in soap sample containing soap and SLES surfactant by using conventional method
[0062] The process is described as follows:
a) 2.0012 g soap sample was extracted with 85 percent alcohol.
b) The alcohol insoluble portion was discarded.
15 c) The alcohol soluble portion was made up to 250 ml.
d) 100 ml of the step c) was evaporated to 25 ml and refluxed with 50 ml of 2N
sulphuric acid.
e) Sample of step d) was extracted with petroleum ether and washed with 1 percent
sodium bicarbonate solution.
20 f) Petroleum ether was evaporated and the residue was weighed as TFM (M) =
0.3285.
% TFM = mass in gm of residue * 250/mass in gm of sample = 0.3285*250/2.0012 = 41.04. [0063] As can be observed from the Examples 3 and 5, the process of the present
25 disclosure was found to be comparable in accuracy when compared with the
conventional method as described in Examples 4 and 6. Surfactants such as alpha olefin sulfonate (AOS) or sodium lauryl ether sulfate (SLES) can cause unwanted interference in the determination of fatty acid content. However, as can be seen from these examples, the accuracy is maintained in spite of presence of surfactants.
30 Additionally, the process as described in Examples 3 and 5, was effective at room
21

temperature, while the conventional method employed high temperature and was also time-consuming.
Advantages of the present disclosure:
[0064] The present disclosure reveals efficient process for determination of total
5 fatty matter in soap by cutting down the time of TFM analysis from a minimum of
7-8 hours (for conventional method) to approximately 30-35 minutes. Furthermore, said process is cost effective as it can be carried out at room-temperature using economical ingredients, such as, benzethonium chloride.
10
22

I/We Claim:
1. An efficient process for determination of total fatty matter in soap, said
process comprising the steps of:
a) obtaining a soap;
5 b) contacting the soap with water to obtain a first mixture;
c) contacting a first portion of the first mixture with at least one solvent, at least one indicator, and chloroform to obtain a second mixture;
d) titrating the second mixture with at least one titrant that changes color at a first end point;
10 e) recording the amount of the at least one titrant added to the second
mixture to obtain a first volume;
f) contacting a second portion of the first mixture with at least one
indicator, chloroform and at least one acid to obtain a third mixture;
g) titrating the third mixture with at least one titrant that changes color
15 at a second end point;
h) recording the amount of the at least one titrant added to the third
mixture to obtain a second volume; and
i) determining total fatty matter in the soap by using the first, and the
second volume,
20 wherein the process is carried out within a period in the range of 30 - 35
min.
2. The process for determination of total fatty matter in soap as claimed in
claim 1, wherein the process is carried out in at a temperature in the range
of 18 - 32 ℃.
25 3. The process for determination of total fatty matter in soap as claimed in
claim 1, wherein the total fatty matter of soap comprises a salt of at least one alkali metal, and a mixture of C8-C20 fatty acids. 4. The process for determination of total fatty matter in soap as claimed in claim 3, wherein the soap further comprises at least one surfactant.
23

5. The process for determination of total fatty matter in soap as claimed in
claim 4, wherein the surfactant is selected from the group consisting of alpha
olefin sulfonates, sodium lauryl ether sulfate, and combinations thereof.
6. The process for determination of total fatty matter in soap as claimed in
5 claim 1, wherein the at least one titrant is selected from the group consisting
of benzethonium chloride, cetyltrimethylammonium bromide (CTAB), cetrimmonium chloride (CTAC), and combinations thereof.
7. The process for determination of total fatty matter in soap as claimed in
claim 1, wherein the at least one solvent is selected from the group
10 consisting of water-ethanol mixture, ethanol, isopropanol, methanol, and
combinations thereof.
8. The process for determination of total fatty matter in soap as claimed in
claim 1, wherein the at least one indicator is selected from the group
consisting of xylene cyanol FF, disulfine blue, and combinations thereof.
15 9. The process for determination of total fatty matter in soap as claimed in
claim 1, wherein the at least one acid is selected from the group consisting of sulfuric acid, hydrochloric acid, and combinations thereof.
10. The process for determination of total fatty matter in soap as claimed in
claim 1, wherein the at least one indicator present in the second mixture has
20 a concentration in the range of 8.35 x 10-5 – 10.21 x 10-5 M.
11. The process for determination of total fatty matter in soap as claimed in
claim 1, wherein the at least one indicator present in the third mixture has a
concentration in the range of 16.71 x 10-5 – 20.42 x 10-5 M.
12. The process for determination of total fatty matter in soap as claimed in
25 claim 1, wherein the at least one solvent to the chloroform present in the
second mixture has a weight ratio in the range of 1:0.8 – 1:1.1.
13. The process for determination of total fatty matter in soap as claimed in
claim 1, wherein the third mixture has at least one acid in the range of 0.03
–0.05 M.
30 14. The process for determination of total fatty matter in soap as claimed in
claim 1, wherein the second mixture has a pH in the range of 9.5 – 9.7.
24

15. The process for determination of total fatty matter in soap as claimed in claim 1, wherein the third mixture has a pH in the range of 0.6 - 0.9.
25