PUBLIC REVIEW DRAFT DRAFT UGANDA STANDARD  
  DUS DEAS 9 8 
Second  Edition  
2018-mm-dd 
 
 Reference number  
DUS DEAS 9 8: 2017  
© UNBS 201 8 
  
Curry Powder — Specification 
 PUBLIC REVIEW DRAFTDUS DEAS 98: 2017 
ii                © UNBS  2018 - All rights reserved 
 Compliance with this standard does not, of itself confer immunity from legal obligations  
A Uganda Standard does not purport to include all necessary provisions of a contract. Users are 
responsible for its correct application  
© UNBS 2018 
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilised in any 
form or by any means, electronic or mechanical, including photocopying and microfilm, without prior written 
permission from UNBS. 
Requests for permission to reproduce this document should be addressed to 
The Executive Director 
Uganda National Bureau of Standards 
P.O. Box 6329 
Kampala 
Uganda 
Tel: +256 417 333 250 /1/2 
Fax: +256 414 286 123 
E-mail: info@unbs.go.ug  
Web: www.unbs.go.ug  
 PUBLIC REVIEW DRAFTDUS DEAS 98: 2017 
© UNBS  2018 - All rights reserved                iii National foreword 
Uganda National Bureau of Standards (UNBS) is a parastatal under the Ministry of Trade, Industry and 
Cooperatives established under Cap 327, of the Laws of Uganda, as amended.  UNBS is mandated to co-
ordinate the elaboration of standards and is  
(a) a member of International Organisation for Standardisation (ISO) and  
(b) a contact point for the WHO/FAO Codex Alimentarius Commission on Food Standards, and  
(c) the National Enquiry Point on TBT Agreement of the World Trade Organisation (WTO). 
The work of preparing Uganda Standards is carried out through Technical Committees. A Technical 
Committee is established to deliberate on standards in a given field or area and consists of representatives of 
consumers, traders, academicians, manufacturers, government and other stakeholders. 
Draft Uganda Standards adopted by the Technical Committee are widely circulated to stakeholders and the 
general public for comments. The committee reviews the comments before recommending the draft standards 
for approval and declaration as Uganda Standards by the National Standards Council.  
This Uganda Standard, DUS DEAS 98: 2017 , Curry Powder — Specification,  is identical with  and has been 
reproduced from an East African Standard, DEAS 98: 2017, Curry Powder — Specification , and adopt ed as a 
Uganda Standard. 
The committee responsible for this document is Technical Committee UNBS/TC 2, Food and agriculture 
Subcommittee SC 4 , Fruits , Vegetables, Spices and related products. 
This Second edition cancels and replaces the first edition, US EAS 98:1999 , Curry Powder — Specification , 
which has been technically revised. 
Wherever the words , “East African Standard" appear, they should be replaced by "Uganda Standard." 
 
  PUBLIC REVIEW DRAFT
 DEAS 98: 2017  
ICS 67.220  
 
© EAC 2017                                                                                                                          Second Edition 2017 
 DRAFT EAST AFRICAN STANDARD 
Curry powder — Specification 
EAST AFRICAN COMMUNITY PUBLIC REVIEW DRAFTPUBLIC REVIEW DRAFTDEAS 98: 2017 
ii © EAC  2017  – All rights reserved  
 Copyright notice 
This EAC document is copyright-protected by EAC. While the reproduction of this document by 
participants in the EAC standards development process is permitted without prior permission from EAC, 
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 PUBLIC REVIEW DRAFTDEAS 98: 2017  
© EAC 2017  – All rights reserved  iii 
 Foreword 
Development of the East African Standards has been necessitated by the need for harmonizing requirements 
governing quality of products and services in the East African Community. It is envisaged that through 
harmonized standardization, trade barriers that are encountered when goods and services are exchanged 
within the Community will be removed.  
The Community has established an East African Standards Committee (EASC) mandated to develop and 
issue East African Standards (EAS).  The Committee is composed of representatives of the National 
Standards Bodies in Partner States, together with the representatives from the public and private sector 
organizations in the community .  
East African Standards are developed through Technical Committees that are representative of key 
stakeholders including government, academia, consumer groups, private sector and other interested parties. 
Draft East African Standards are circulated to stakeholders through the National Standards Bodies in the 
Partner States. The comments received are discussed and incorporated before finalization of standards, in 
accordance with the Principles and procedures for development of East African Standards. XXXXXX. 
East African Standards are subject to review, to keep pace with technological advances. Users of the East 
African Standards are therefore expected to ensure that they always have the latest versions of the standards 
they are implementing.  
The committee responsible for this document is Technical Committee EASC/TC 006, Spices culinary herbs 
and condiments . 
This second edition cancels and replaces th e first edition (EAS 98: 1999), which has been technically revised. 
Attention is drawn to the possibility that some of the elements of this document may be subject of patent 
rights. EAC shall not be held responsible for identifying any or all such patent rights. 
 
 PUBLIC REVIEW DRAFTPUBLIC REVIEW DRAFTDRAFT EAST AFRICAN STANDARD  DEAS 98: 2017 
 
© EAC 2017  – All rights reserved  1 
 Curry powder — Specification  
1 Scope  
This Draft East African Standard specifies the requirements and the methods of sampling and test for curry 
powder, which is used as a flavouring material in the preparation of foods.  
2 Normative references  
The following documents are referred to in the text in such a way that some or all of their content constitutes 
requirements of this document. For dated references, only the edition cited applies. For undated references, 
the latest edition of the referenced document (including any amendments) applies. 
EAS 38, General standard for the labelling of pre-packaged foods  
EAS 99, Spices and condiments  —Terminology  
EAS 100, Food stuffs — Determination of lead  
ISO 948, Spices and condiments — Sampling  
ISO 939, Spices and condiments — Determination of moisture content Entrainment method  
ISO 6633, Fruits, vegetables and derived products — Determination of lead content — Flameless atomic 
absorption spectrometric method  
3 Terms and definitions  
For the purposes of this document, the terms and definitions given in EAS 99 and the following apply. 
Curry powder  
is a product used as a condiment prepared by grinding clean and wholesome spices, aromatic herbs and 
seeds and sometime starch and salts added to it. 
4 Requirements 
Curry powder shall be prepared by grinding clean, dried and sound spices and condiments. The major 
ingredients shall include turmeric, coriander, cumin, fenugreek and mustard. In addition any of the spices 
and condiments listed in EAS 99 may be used.  The proportion of spices used in curry powder shall not be 
less than 85%. Curry powder may contain edible starchy material (the nature of which shall be declared), 
and the extent of which shall be determined in accordance with the method given in Annex A .  
4.2 General requirements  
Curry powder shall: PUBLIC REVIEW DRAFTDEAS 98: 2017 
2 © EAC  2017  – All rights reserved  
 a) have characteristic fresh taste and odour of the designated product ,  
b) be free from dirt, fungal growth and insect infestation.  
c) be free  from added colouring, flavouring substances and preservatives other than salt. 
4.3 Specific requirements 
4.3.1  Curry powder shall comply with the requirements in Table 1.  
Table 1 — Requirements for curry powder 
S/No  Characteristics  Requirements  Test method  
i)  Moisture percent m/m max.  10.00  ISO 939  
ii)  Volatile oil ml/100g min. 0.25 ISO 6571  
iii)  Non-volatile ether extract percent m/m, min. 7.5 ISO 1108  
iv)  Acid insoluble ash in hydrochloric acid percent 
m/m max.  1.0 ISO 930  
v)  Salt percent m/m max.  5.0 Annex B  
vi)  Crude fibre percent max.  15.0 Annex C  
 
4.3.2  Curry powder shall be ground to such fineness that all of it passes through a sieve of 500 micron 
(0.500 mm) and nothing remains on the sieve. 
5 Food additives  
Curry powder shall be free from added colouring matter and preservatives other than salt  
6 Contaminants  
6.1 Pesticide residues 
Pesticide residues in curry powder shall not exceed maximum residue limit as established in the Codex 
online guideline for pesticide residues in food. 
6.2 Heavy metal 
Heavy metals in curry powder shall not exceed maximum residue limit as stipulated in Codex Stan 193. 
6.3 Aflatoxin limits. 
Total aflatoxin shall not exceed 10 µg/L and aflatoxin B1 shall not exceed 5 µg/L when tested with ISO 
16050  
7 Hygiene 
Curry powder shall be manufactured and handled in a hygienic manner in accordance with EAS 39 and shall 
conform to the microbiological limits stipulated in Table 2. PUBLIC REVIEW DRAFTDEAS 98: 2017  
© EAC 2017  – All rights reserved  3 
 Table 2 — Microbiological requirements 
S/No  Characteristic  Requirements  Test method  
i)  Total plate count, cfu/g, max  1x105 ISO 4833 -1 
ii)  Yeast  and mould, cfu/g , max.  1x103 ISO 7954  
iii)  Salmonella spp . per 25 g  Absent  ISO 6579  
iv)  E. coli , MPN/g, max.  Absent  ISO 7251  
 
8 Weights and measures 
The weight and fill of the curry powder shall comply with the weights and measures regulations of Partner 
States or equivalent legislation. 
9 Packaging  
9.1 Curry powder shall be packed in clean and sound container made of food grade material and sealed with 
temper-proof seal. The container shall be made of a material which does not impart any smell or react with 
curry powder and protects it from ultra-violet radiation, ingress of moisture and loss of volatile matter. 
9.2 The packaging material shall be easy to sterilize, shall not be a source of contamination, and shall 
protect the product safety and quality during transportation and storage.  
10 Labelling 
The product shall be legibly and indelibly labelled in compliance with the requirements of EAS 38. In addition 
the following information shall  appear legibly on each container: 
a) name of the product; 
b) trade name or brand name if any; 
c) name, physical and postal a address of manufacturer and / or packer; 
d) batch or code number; 
e) net weight; 
f) a complete list of ingredients in descending order of proportions; 
g) storage conditions; and 
h) manufacturing and expire date. 
10 Sampling  
Sampling shall be carried out in accordance with ISO 948. PUBLIC REVIEW DRAFTDEAS 98: 2017 
4 © EAC  2017  – All rights reserved  
 Annex A 
(normative) 
 
Determination of starch — Acid hydrolysis method 
A.1 Principle  
Extracted starch from the curry powder is hydrolysed and titrated against standard Fehling's solution and the 
dextrose content in the sample is initially determined. The dextrose content is determined from the titre value 
and the starch content is calculated from this.  
A.2 Reagents  
A.2.1 Diethyl ether  
A.2.2 Ethanol, 10 % (volume fraction).  
A.2.3  Hydrochloric acid, 2.5 % (volume fraction), prepared by mixing 20 ml of concentrated 
hydrochloric acid (density  = 1.16 g/ml) and 200 ml of water.  
A.2.4  Sodium carbonate  solution, of concentration 20 g/l.  
A.2.5 Stock solution  of dextrose  
Weigh accurately 10 g of anhydrous dextrose into a one-mark 1000 ml graduated flask and dissolve it in 
water. Add to this solution 2.5 g of benzoic acid. Shake to dissolve the benzoic acid and dilute to the mark 
with water. This solution should not be used after 48 hours .  
A.2.6 Standard solution of dextrose  
Dilute a known aliquot portion of the stock solution of dextrose (A.2.5) with water containing 0.25 g/l of 
benzoic acid to such a concentration that more than 15 ml but less than 50 ml of it will be required to reduce 
all the copper in the Fehling's solution (A.2.8) taken for titration. Note the concentration of anhydrous 
dextrose in this solution in milligrams per 100 ml (see note). Prepare a fresh solution every day.  
NOTE  When 10 ml of Fehling's solution are taken for titration, a standard dextrose solution containing 0.11 g/l to 
0.30 g/l of anhydrous dextrose is convenient for use.  
A.2.7 Methylene  blue indicator solution  
Dissolve 0.2 g of Methylene blue in water and dilute to 100 ml.  
A.2.8 Fehling's solution (Soxhlet modification)  
A.2.8.1 Preparation  
Mix immediately before use, equal volumes of solution A and solution 8 which are prepared as follows.  
Solution A: dissolve 34.64 g of copper sulfate pentahydrate (CuSO 4.5H 20) in water in a flask. Add 0.5 ml of 
concentrated sulfuric acid (p = 1.84 g/ml) and dilute to 500 ml. Filter or decant if necessary.  PUBLIC REVIEW DRAFTDEAS 98: 2017  
© EAC 2017  – All rights reserved  5 
 Solution B: dissolve 173 g of potassium sodium tartrate (KNaC 4H406-4H 20) and 50 g of sodium hydroxide 
in a volumetric flask. Dilute to 500 ml and allow the solution to stand for 2 days. Filter or decant this solution, 
if necessary.  
A.2.8.2 Standardization of Fehling's solution  
Pour the standard dextrose solution (A.2.6) into a 50 ml burette (see note 2). Find the titre (i.e. the volume of 
standard dextrose solution required to reduce all the copper in 10 ml of Fehling's solution) corresponding to 
the concentration of the standard dextrose solution, using Table A.1.  
NOTE 1  If, for example, the standard dextrose solution contains 167.0 mg of anhydrous dextrose per 100 ml, 
the corresponding titre would be 30 ml.  
Pipette 10 ml of Fehling's solution into a 300 ml conical flask and run in from the burette almost the whole of 
the standard dextrose solution required to effect reduction of all the copper, so that not more than 1 ml will 
be required later to complete the titration. Gently boil the contents of the flask for 2 min. At the end of 2 min 
of boiling, add, without interrupting boiling, 1 ml of Methylene blue indicator solution (A.2.7). While the 
contents of the flask continue to boil, begin to add standard dextrose solution (A.2.6) (one or two drops at a 
time) from the burette until the blue colour of the indicator just disappears. The titration should be completed 
within 1 min, so that the contents of the flask boil for 3 min altogether without interruption. Record the titre.  
Multiply the titre (obtained by direct titration) by the number of milligrams of anhydrous dextrose in 1 ml of 
the standard dextrose solution to obtain the dextrose factor. Compare this factor with the dextrose factor 
given in Table A.1 and determine the correction, if any, to be applied to the dextrose factors derived from 
Table A.1.  
NOTE 2  In adding the dextrose solution to the reaction mixture, the burette may be held in the hand over the 
flask. The burettes may be fitted with a small outlet tube, bent twice at right angles, so that the body of the burette 
may be kept out of the steam while adding the solution. Burettes with glass taps are unsuitable for this work as the 
taps become heated by the steam and are liable to jam.  
It should be noted that with both incremental and standard methods of titration, the flask containing the 
reaction mixture is left on the wire gauze over the flame throughout the titration.  
A.2.8.3 Example 
Concentration of anhydrous dextrose in the standard dextrose solution: 67.0 mg per 100 ml  
Titre obtained by direct titration: 30.1 ml 
Dextrose factor for 30.1 ml of standard = Titre in milliliters x number of milligrams of anhydrous dextrose 
solution = 30.1 x 1.670 = 50.267 
Dextrose factor for 30.1 ml of standard dextrose solution from Table A .1 (calculated by interpolation): 50.11 
Correction to apply to the dextrose factor derived from Table A.1 50.267-50.11=0.57 
A.3 Apparatus 
Usual laboratory apparatus and, in particular, the following. PUBLIC REVIEW DRAFTDEAS 98: 2017 
6 © EAC  2017  – All rights reserved  
 A.3.1 One-mark volumetric flasks, of capacity 1 000 ml, 500 ml and 250 ml.  
A.3.2 Analytical balance,  capable of weighing to an accuracy of ± 0,001 g.  
A.3.3 Burette, of capacity 50 ml.   
A.3.4 Conical flasks, of capacity 300 ml.   
A.3.5 Reflux condenser  
A.4 Procedure  
A.4.1 Preparation of test solution  
Extract 0.5 g of curry powder, accurately weighed, with five 10 ml portions of diethyl ether ( A.2.1), then pass 
the solution through a filter paper that will retain completely the smallest starch granules. Evaporate the 
diethyl ether from the residue and wash with 150 ml of ethanol (A.2.2). Carefully wash off the residue from 
the filter paper with 200 ml of cold water. Heat for 2 h the undissolved residue with 220 ml of dilute 
hydrochloric acid (A.2.3) in a flask equipped with a reflux condenser A.3.5). Cool and neutralize with sodium 
carbonate solution (A.2.4). Transfer the solution quantitatively to a 250 ml flask and dilute to the mark with 
water.  
A.4.2 Incremental method of titration  
Pour the test solution (A.4.1) into a 50 ml burette (the solution may be filtered if not clear) (see note 2 in 
A.2.8.2). Pipette 10 ml of Fehling's solution (A.2.8) into a 300 ml conical flask and run in from the burette 15 
ml of the solution. Without further dilution, heat the contents of the flask over wire gauze, and boil. After the 
liquid has been boiling for about 15 seconds, it will be possible to judge if almost all the copper has been 
reduced, then add 1 ml of Methylene blue indicator solution (A.2.7). Continue boiling the contents of the flask 
for 1 min to 2 min from the commencement of boiling, and then add the solution from the burette in small 
quantities (1 ml or less at a time), allowing the liquid to boil for about 10 seconds between successive 
additions, until the blue colour of the indicator just disappears (see note 1).  
In the case where there still appears to be much unreduced copper after the mixture of Fehling's solution 
with 15 ml of the prepared solution has been boiling for 15 seconds, add the solution from the burette in 
larger increments (more than 1 ml at a time, according to judgment), and allow the mixture to boil for 15 
seconds after each addition.  
Repeat the addition of the solution at intervals of 15 seconds until it is considered unsafe to add a large 
increment of the test solution. At this stage continue the boiling for an additional 2 min, then add 1 ml of 
indicator and complete the titration by adding the test solution in small quantities (less than 1 ml at a time) 
(see note 2).  
NOTE 1  It is advisable not to add the indicator until the endpoint has been nearly reached, because the indicator 
retains its full colour until the endpoint is almost reached and thus gives no warning to the operator to go slowly.  
NOTE 2  When the operator has had some experience with the method, a sufficiently accurate result may often be 
obtained by a single estimation by the incremental method of titration. For the utmost degree of accuracy of which the 
method is a second titration should be carried out by the standard method of titration (A.4.3).  
A.4.3 Standard method of titration  
Pipette 10 ml of Fehling's solution (A.2.8) into a 300 ml conical flask and run in from the burette aim the test 
solution required to effect reduction of all the copper (determined under A.4.2) so that, if possible not more 
than 1 ml will be required to complete the titration. Gently boil the contents of the flask for 2 min. At the end 2 
min of boiling, add, without interrupting the boiling, 1 ml of Methylene blue indicator solution contents of the PUBLIC REVIEW DRAFTDEAS 98: 2017  
© EAC 2017  – All rights reserved  7 
 flask continue to boil, begin to add the solution (one or two drops at a time) from the burette until colour of 
the indicator just disappears (see note 1 in A.4.2). The titration should be completed within 1 min so that the 
contents of the flask boil altogether for 3 min without interruption.  
A.5 Calculation  
A.5.1 Refer to Table A.1 for the dextrose factor corresponding to the titre (determined as given under A.4.3) 
and apply the correction previously determined under A.2.8.2. Calculate the dextrose content of the test 
solution (A.4.1) as follows:  
 
where  
 m = is the mass, in milligrams, of anhydrous dextrose present in 1 ml of the test solution;  
 f = is the dextrose factor;  
           VT = is the titre used 
Instead of using 10 ml of Fehling's solution, a 25 ml portion may also be substituted throughout the 
procedure (including standardization of the Fehling's solution A.2.8.2)). In this case, the standard dextrose 
solution used in standardizing the Fehling's solution, and the test solution (A.4.1), should contain 0.25 g/l to 
0.75 g/l of anhydrous dextrose, and Table A.2 should be used for the calculation.  
Tables A.1 and A.2 show, for the standard method of titration, the values corresponding to integral millilitres 
of the sugar solutions, intermediate values being obtained by interpolation. 
A.5.2 The starch content (on dry basis), ws as a mass fraction in percent, is given by:  
Ws =      9.3 m DV       
         m c (100-w M) 
Where: 
mD  is the mass, in milligrams, of anhydrous dextrose in 1 ml of solution (A.2.5);  
V is the total volume, in millilitres, of the test solution (A.4.1);  
mC  is the mass, in grams, of the curry powder used to prepare V ml of the test solution;  
wM  is the moisture content of the curry powder, as a mass fraction in percent.  
 
 
 
 
 PUBLIC REVIEW DRAFTDEAS 98: 2017 
8 © EAC  2017  – All rights reserved  
  
Table A.1 — Dextrose factor for 10 ml of Fehling's solution 
S/No.  Titre ( ml)  Dextrose factor (  Fa) Dextrose content per 100 ml of 
solution  (mg)  
1)  15 49.1 327 
2)  16 49.2 307 
3)  17 49.3 289 
4)  18 49.3 274 
5)  19 49.4 260 
6)  20 49.5 247.4  
7)  21 49.5 235.8  
8)  22 49.6 225.5  
9)  23 49.7 216.1  
10)  24 49.8 207.4 
11)  25 49.8 199.3  
12)  26 49.9 191.8  
13)  27 50.0 184.9  
14)  28 50.0 178.5  
15)  29 50.0 172.5  
16)  30 50.1 167.0  
17)  31 50.2 161.8  
18)  32 50.2 156.9  
19)  33 50.3 152.4  
20)  34 50.3 148.0  
21)  35 50.4 143.9  
22)  36 50.4 140.0  
23)  37 50.5 136.4  
24)  38 50.5 132.9  
25)  39 50.6 129.6  
26)  40 50.6 126.5 
27)  41 50.7 123.6  
28)  42 50.7 120.8  
29)  43 50.8 118.1  
30)  44 50.8 115.5  
31)  45 50.9 113.0  
32)  46 50.9 110.6  
33)  47 51.0 108.4  
34)  48 51.0 106.2  
35)  49 51.0 104.1  
36)  50 51.1 102.2  PUBLIC REVIEW DRAFTDEAS 98: 2017  
© EAC 2017  – All rights reserved  9 
 If the value obtained is not comparable with the value given in this table, then the standar d sample of anhydrous 
dextrose shall be rechecked.  
a Milligrams of anhydrous dextrose corresponding to 10 ml of Fehling's solution. Fehling's solution.  
 
Table A.2 — Dextrose factor for 25ml of Fehling’s solution  
S/No . Titre (ml)  Dextrose factor (  Fa) Dextrose content per 100 ml of solution  
(mg)  
1)  15 120.2  801 
2)  16 120.2  751 
3)  17 120.2  707 
4)  18 120.2  668 
5)  19 120.3  638 
6)  20 120.3  601,5  
7)  21 120.3  572,9  
8)  22 120.4  547,3  
9)  23 120.4  523,6  
10)  24 120.5  501,9  
11)  25 120.5  482,0  
12)  26 120.6  463,7  
13)  27 120.6  446,8  
14)  28 120.7  431,0  
15)  29 120.7  416,4  
16)  30 120.8  402,7  
17)  31 120.8  389,7  
18)  32 120.8  377,6  
19)  33 120.9  366,3  
20)  34 120.9  355,6  
21)  35 121.0  345,6  
22)  36 121.0  336,3  
23)  37 121.1  327,4  
24)  38 121.2  318,8  
25)  39 121.2  310,7  
26)  40 121.2  303,1  
27)  41 121.3  295,9  
28)  42 121.4  289,0  
29)  43 121.44  282,4  
30)  44 121.5  276,1  
31)  45 121.5  270,1  
32)  46 121.6  264,3  
33)  47 121.6  258,8  PUBLIC REVIEW DRAFTDEAS 98: 2017 
10 © EAC  2017  – All rights reserved  
 34)  48 121.7  253,5  
35)  49 121.7  248,4  
36)  50 121.8  243,6  
If the value obtained is not comparable with the value given in this tabl e, then the standard sample of anhydrous 
dextros e shall  be rechecked.  
a Milligrams of anhydrous dextrose corresponding to 25 ml of Fehling's solution  
 
 
 
 
 PUBLIC REVIEW DRAFTDEAS 98: 2017  
© EAC 2017  – All rights reserved  11 
 Annex B 
(normative) 
 
Determination of salt (Sodium chloride ) 
B.1 Reagents  
B.1.1  Dilute nitric acid:  One volume of concentrated nitric acid (relative density 1.42)  diluted with 4 
volumes of water and freed from lower oxides of nitrogen by boiling until colourless.  
B.1.2  Standard silver nitrate solution 0.1 N  
B.1.3  Ferric indicator solution:  Saturated solution of ferric ammonium sulphate [FeNH 4. (SO 4)2 2H2O] 
B.1.4  Standard potassium thiocyanate solution 0.1 N 
B.2 Procedure:  
Weigh accurately about 2-5 g of the material in a dish preferably of platinum and obtain the total ash as 
described in ISO 928 Dissolve the ash in hot water. Filter and wash the dish and residue thoroughly with hot 
water till it is free from chlorides. Collect the filtrate and washings in an Erlenmeyer flask. Add a known 
volume of the standard silver nitrate solution in slight excess, 5 ml of the ferric indicator solution and a few 
milliliters of nitric acid. Titrate the excess silver nitrate with the standard potassium thiocyanate solution until 
permanent light brown colour appears  
B.3 Calculation  
Sodium chloride per cent by mass  = 5.85 ( V 1N1 -V2N2) 
                                                                                                 M  
Where: 
V1= Volume in ml of the standard silver nitrate solution used 
N1= Normality of the standard silver nitrate solution used 
V2= Volume in ml of the standard potassium thiocyanate solution and 
N2= Normality of the standard potassium thiocyanate solution and 
M= Mass in g of the material taken for the test  
 
 PUBLIC REVIEW DRAFTDEAS 98: 2017 
12 © EAC  2017  – All rights reserved  
 ANNEX C 
(normative) 
Determination of crude fibre  
C.1 Reagents 
C.1.1  Petroleum ether :   
C.1.2  Dilute sulphuric acid : 1.25 % (m/v)  accurately prepared.  
C.1.3  Sodium hydroxide solution : 1.25 % (m/v)  accurately prepared.  
C.1.4 Ethanol : 95 % (v/v) 
C.2 Procedure:  
Weigh accurately about 2.5 g of the ground material into a thimble and extract for about 1 hour with 
petroleum ether using a Soxhlet apparatus. Transfer the material in the thimble to a one-litre flask. Take 200 
ml of the dilute sulphuric acid in a beaker and bring to boil. Transfer the whole of the boiling acid to the flask 
containing the fat-free material and immediately connect the flask with a water-cooled reflux condenser and 
heat so that the contents of the flask begin to boil within 1 minute. Rotate the flask frequently taking care to 
keep the material from remaining on the sides of the flask and out of contact with the acid. Continue boiling 
for exactly 30 minutes. Remove the flask and filter through fine linen (about 18 thread to the centimetre) or 
through a coarse acid washed hardened filter paper, held in a funnel  and wash with boiling water until the 
washings are no longer acidic to litmus paper. Bring some quantity of sodium hydroxide solution to boil 
under reflux condenser. Wash the residues on the filter into the flask with 200 ml of boiling sodium hydroxide 
solution. Immediately connect the flask with the reflux condenser and boil for exactly 30 minutes. Remove 
the flask and  immediately filter through the linen or the filter paper. 
Thoroughly wash the residue with boiling water and transfer to a Gooch crucible prepared with a thin 
but compact layer of ignite asbestos. Wash the residue thoroughly first with hot water and then with 
about 15 ml of ethyl alcohol and with three successive washings of 15 ml of petroleum ether each. Dry 
the Gooch crucible and contents at 105 ± 1o C in an air-oven for 3 hours, cool and weigh. Repeat the 
process of drying for 30 minutes, cooling and weighing until the difference between two consecutive 
weighings is less than 1 mg. Incinerate the contents of the Gooch crucible in the muffle furnace at 550 ± 20 
oC until all the carbonaceous matter is burnt. Cool the Gooch crucible containing the ash in a desiccator  arid 
weigh.  
C.3 Calculation   
Crude fibre (on dry basis), percent by mass 
   = l00 (M 1 – M2)  *   100 
                        M          (100- H) 
Where:   M 1 = mass in g of Gooch crucible and contents before ashing.  
               M 2 = mass in g of Gooch crucible containing asbestos and ash,  PUBLIC REVIEW DRAFTDEAS 98: 2017  
© EAC 2017  – All rights reserved  13 
                M = mass in g of the material taken for the test 
     H= moisture content of the sample as received in percent  
 
 PUBLIC REVIEW DRAFTPUBLIC REVIEW DRAFTDEAS 98: 2017    
 
© EAC 2017  – All rights reserved