FINAL DRAFT UGANDA 
STANDARD  
  FDUS EAS 337 
First  Edition  
2013-mm-dd 
 
 Reference number  
FDUS EAS 337: 2013 
© UNBS 201 3 
  
Henna powder  — Specification  
 FDUS EAS 337: 2013 
ii                © UNBS  2013 - 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 f or its correct application  
© UNBS 20 13 
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 wri tten 
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 41 505 995  
Fax: 256 41 286 123  
E-mail: unbs@infocom.co.ug  
Web: www.unbs.go.ug  
 FDUS EAS 337: 2013 
© UNBS  2013 - All rights reserved                 iii National foreword  
Uganda National Bureau of Standards (UNBS) is a parastatal under the Ministry of Tourism, Trade and 
Industry established under Cap 327, of the Laws of Uganda. UNBS is mandate d 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/SPS Agreemen ts 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 
consum ers, 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 rec ommending the draft standards 
for approval and declaration as Uganda Standards by the National Standards Council.  
This Final Draft Uganda Standard, FDUS EAS 337: 2013, Henna powder  — Specification , is identical with  and 
has been r eproduced from an East African  Standard, EAS 337: 2013, Henna powder  — Specification , and is 
being proposed for adoption as a Uganda Standard.  
Wherever the words, “ East African  Standard" appear, they should be replaced by "Uganda Standard."   EAS 337: 2013 
ICS 71.100.70  
© EAC 2013                                                                                                                         Second Edition 2013  
 
EAST AFRICAN STANDARD  
 
Henna powder — Specification  
EAST AFRICAN COMMUNITY  EAS 337: 2013 
ii © EAC  2013 – 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 with out prior permission from EAC, 
neither this document nor any extract from it may be reproduced, stored or transmitted in any form for 
any other purpose without prior written permission from EAC.  
Requests for permission to reproduce this document for the pu rpose of selling it should be addressed 
as shown below or to EAC’s member body in the country of the requester:  
© East African Community 2013 — All rights reserved  
East African Community   
P.O.Box 1096  
Arusha  
Tanzania  
Tel: 255 27 2504253/8  
Fax: 255 27 25044 81/2504255  
E-mail: eac@eachq.org  
       Web: www.eac -quality.net  
Reproduction for sales purposes may be subject to royalty payments or a licensing agreement.  
Violators may be persecuted  EAS 337: 2013 
© EAC 2013 – All rights reserved  iii 
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ .............................  v 
1 Scope  ................................ ................................ ................................ ................................ ......................  1 
2 Normative references  ................................ ................................ ................................ ............................  1 
3 Requirements  ................................ ................................ ................................ ................................ .........  1 
3.1 General requirements  ................................ ................................ ................................ ...........................  1 
3.2 Specific quality requirements  ................................ ................................ ................................ ..............  1 
4 Packaging and labelling ................................ ................................ ................................ ........................  2 
4.1 Packaging  ................................ ................................ ................................ ................................ ...............  2 
4.2 Labelling  ................................ ................................ ................................ ................................ .................  2 
5 Sampling  ................................ ................................ ................................ ................................ ................  2 
5.1 General  ................................ ................................ ................................ ................................ ...................  2 
5.2 Scale of sampling  ................................ ................................ ................................ ................................ .. 3 
5.3 Test samples and reference sample  ................................ ................................ ................................ .... 3 
5.3.1  Preparation of test sample  ................................ ................................ ................................ ...................  3 
5.3.2  Reference sample  ................................ ................................ ................................ ................................ .. 3 
6 Methods of test  ................................ ................................ ................................ ................................ ...... 4 
6.1 Quality of reagents  ................................ ................................ ................................ ................................  4 
6.2 Preparation of sample for analysis  ................................ ................................ ................................ ...... 4 
Annex  A (normative)  Determination of moisture and volatile matter  ................................ ..........................  5 
A.1 Procedure  ................................ ................................ ................................ ................................ ...............  5 
A.2 Calculation  ................................ ................................ ................................ ................................ .............  5 
Annex B (normative)  Determination of cold water extract  ................................ ................................ ............  6 
B.1 Procedure  ................................ ................................ ................................ ................................ ...............  6 
B.2 Calculation  ................................ ................................ ................................ ................................ .............  6 
Annex C (normative)  Determination of crude fibre  ................................ ................................ ........................  7 
C.1 Reagents  ................................ ................................ ................................ ................................ ................  7 
C.2 Procedure  ................................ ................................ ................................ ................................ ...............  7 
C.3 Calculation  ................................ ................................ ................................ ................................ .............  7 
Annex D (normative)  Determination of mineral matter  ................................ ................................ ..................  8 
D.1 Procedure  ................................ ................................ ................................ ................................ ...............  8 
D.2 Calculation  ................................ ................................ ................................ ................................ .............  8 
Annex E (normative)  Determination of acid insoluble ash  ................................ ................................ ...........  9 
E.1 Reagent  ................................ ................................ ................................ ................................ ..................  9 
E.2 Procedure  ................................ ................................ ................................ ................................ ...............  9 
E.3 Calculation  ................................ ................................ ................................ ................................ .............  9 
Annex F (normative)  Determination of extraneous sand  ................................ ................................ ............  10 
F.1 Procedure  ................................ ................................ ................................ ................................ .............  10 
F.2 Calculation  ................................ ................................ ................................ ................................ ...........  10 
Annex G (normative)  Thin layer chromatographic (TLC) test for detection of ext raneous dyes  ............  11 
G.1 Preparation of plates  ................................ ................................ ................................ ...........................  11 
G.2 Preparation of sample  ................................ ................................ ................................ .........................  11 
G.3 Development of chromatogram  ................................ ................................ ................................ .........  11 
G.4 Results  ................................ ................................ ................................ ................................ ..................  11 
Annex H (normative)  Determination of Lawsone pigment content  ................................ ............................  12 
H.1 Outline of method  ................................ ................................ ................................ ................................  12 EAS 337: 2013 
iv © EAC  2013 – All rights reserved  
 H.2 Apparatus  ................................ ................................ ................................ ................................ ............  12 
H.3 Reagents  ................................ ................................ ................................ ................................ ..............  12 
H.4 Procedure for preparation of Standard Calibration Curve  ................................ .............................  12 
H.5 Calculation  ................................ ................................ ................................ ................................ ...........  12 
Annex I (normative)  Determination of fineness  ................................ ................................ ...........................  13 
I.1 Reagent  ................................ ................................ ................................ ................................ ................  13 
I.2 Procedure  ................................ ................................ ................................ ................................ ............  13 
I.3 Calculation  ................................ ................................ ................................ ................................ ...........  13 
 EAS 337: 2013 
© EAC 2013 – All rights reserved  v 
 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.  
In order to achieve this objective, the Community established an East Afric an Standards Committee mandated 
to develop and issue East African Standards.   
The Committee is composed of representatives of the National Standards Bodies in Partner States, together 
with the representatives from the private sectors and consumer organizat ions. 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 procedures 
of the C ommunity.  
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 .  
EAS 337 was prepared by Technical Committee EAS/TC 071, Cosmetics and cosmetic products.  
This second edition cancels and re places the first edition (EAS 337 :2004), which has been technically revised  
 EAST AFRICAN STANDARD  EAS 337:2013  
 
© EAC 2013 – All rights reserved  1 
 Henna powder — Specification  
1 Scope  
This East African Standa rd specifies  the requirements, and methods of sampling and test for pure henna 
powder.  
2 Normative references  
The following referenced documents are indispensable for the application of this document. For dated  
references, only the edition cited applies. F or undated references, the latest edition of the referenced  
document (including any amendments) applies.  
EAS 346 , Labelling of cosmetics — General requirements  
EAS 377 -1, Cosmetics and cosmetic products — Part 1: List of substances prohibited in cosmetic p roducts  
EAS 377 -2, Cosmetics and cosmetic products — Part 2: List of substances which cosmetic products must not 
contain except subject to the restrictions laid down  
EAS 377 -3, Cosmetics and cosmetic products   Part 3: List of colorants allowed in cosmetic  products  
EAS 377 -4, Cosmetics and cosmetic products   Part 4: List of preservatives allowed in cosmetic products  
EAS 377 -5, Cosmetics and cosmetic products  Part 5: Use of UV filters in cosmetic products  
3 Requirements  
3.1 General requirements  
3.1.1 The material shall be in the form of fine, dried powder obtained from fresh leaves of henna  plant.  
3.1.2 The henna shall be free from extraneous adulterants. These include stems, small  fruits, husk of 
paddy, leaves and twigs of other shrubs.  
3.2 Specific quality requirements  
3.2.1  The ingredients  shall comply with the requirements specified in all parts of EAS 377 . 
3.2.2  The powder shall also comply with the chemical requirements given in Table 1 when tested in  
accordance with the test methods prescribed therei n. EAS 337: 2013 
2 © EAC  2013 – All rights reserved  
 Table 1 — Requirements for henna powder  
S/No.  Characteristic  Requirement  Method of test  
i.  Moisture and volatile matter, % by mass, max . 10 Annex A  
ii.  Cold water extract, % by mass  25 to 32  Annex B  
iii.  Crude fibre, %t by mass  10 to 15  Annex C  
iv.  Mineral mat ter, % by mass  8 to 12  Annex D  
v.  Acid insoluble ash, % by mass  3 to 6  Annex E  
vi.  Extraneous sand, % by mass, max . 5 Annex F  
vii.  Presence of extraneous dyes  To pass the test  Annex G  
viii.  Lawsone pi gment, % by mass, min . 1.0 Annex H  
ix.  Residue on 250 micron sieve, % by mass, max . 5.0 Annex I 
4 Packaging and labell ing 
4.1 Pack aging  
The product shall be pack aged in suitable well -sealed containers that shall protect the contents a nd shall not 
cause any contamination or react with the product.  
4.2 Labelling  
4.2.1  The labelling shall be in accordance with  EAS 346  in English, Kiswahili or French or in combination as 
agreed between the manufacturer and supplier.  
4.2.2  In addition, the labelling shall  include the instructions  for use with  a clear statement that only water 
shall be used as a solvent . 
5 Sampling  
5.1 General  
In drawing, preparing, storing and handling test samples the following precautions and directions shall be 
observed : 
a) samples shall not be taken in an exposed place ; 
b) the sampling instrument shall be clean  and dry ; 
c) precautions shall be taken to protect the samples, the material being sampled, the sampling  instrument, 
and the containers for samples, from adventitious contamination ; 
d) to draw a representative sample, the contents of each container for sampling shall be mixed  as 
thoroughly as  possible by suitable means ; 
e) the sample containers shall be placed in clean dry, airtight glass or other suitable containers ; 
f) the sample containers shall be of such a size that they are almost completely filled by the  sample ; and 
g) each sample container shall be sealed airtight with a suitable stopper after filling, and marked  with full 
details of sampling, the date of sampling and the year of manufacture of the material.  EAS 337: 2013 
© EAC 2013 – All rights reserved  3 
 5.2 Scale of sampling  
5.2.1 All the containers in a singl e consignment of the material drawn from a single batch of  manufacture 
shall constitute a lot. If a consignment is declared to consist of different batches of  manufacture, the batches 
shall be marked separately and the group of containers in each batch sha ll constitute separate lots.  
Samples shall be tested from each lot for ascertaining conformity of the material to the requirements  of the 
specification.  
5.2.2 The number of containers n to be chosen from the lot shall depend on the size of the lot (N)  and shall 
be in  accordance with column 1 and 2 of Table 2.  
Table 2 — Number of containers to be selected for sampling  
Lot size N  Number of containers to be selected  
1 and 2  Each container  
3 to 50  3 
51 to 200  4 
201 to 400  5 
401 to 650  6 
651 to 1000  7 
 
5.2.3 The containers to be selected for sampling shall be chosen at random from the lot and for this 
purpose random number tables shall be used; in case such tables are not available, the following procedure 
shall be adopted:  
Starting from any container coun t them as 1, 2, 3…etc, up to r and so on in a systematic manner, where r is 
the integral part of N/n. Every rth container thus counted shall be withdrawn from the lot.  
5.3 Test samples and reference sample  
5.3.1 Preparation of test sample  
5.3.1.1  Draw with  an appropriate sampling instrument a small portion of the material from different parts  
of each container selected (see Table 2). The total quantity of the material drawn from each  container shall be 
sufficient to conduct the tests for all the characteris tics given under Clause 2  and shall be not less than 0.5 kg.  
5.3.1.2  Thoroughly mix all portions of the material drawn from the container. Equal quantit ies of the  
thoroughly mixed material taken from each of the selected containers shall be well mixed  together so as to  
form a composite sample weighing not less than 0.5 kg. This composite sample  shall be divided into three 
equal parts, one for the purchaser, another for the supplier and the  third for the reference.  
5.3.1.3  Tests for all the requirements give n in Clause 2 shall be conducted on the composite sample.  
5.3.2 Reference sample  
5.3.2.1  The reference sample shall consist of the composite sample marked for this purpose and  shall 
bear the seals of the purchase and the supplier. It shall be kept at a pla ce agreed to between  the purchaser 
and the supplier and shall be used in case of dispute between the two.  
5.3.2.2  A lot shall be declared as conforming to this specification if the composite sample satisfies all  the 
requirements.  EAS 337: 2013 
4 © EAC  2013 – All rights reserved  
 6 Methods of test  
6.1 Qual ity of reagents  
Unless specified otherwise analytical reagent grade chemicals and distilled water shall be used in  tests.  
6.2 Preparation of sample for analysis  
If the sample is in coarse condition, grind and/or crush it as rapidly as possible without loss  or gain of moisture 
and with minimal exposure so that it passes through a 250 -micron sieve. Mix the sample  thoroughly, divide 
and keep at least 100  g portion in a non -corrodible, clean and dry airtight container  for analysis.  EAS 337: 2013 
© EAC 2013 – All rights reserved  5 
 Annex  A 
(normative)  
 
Determin ation of moisture and volatile matter  
A.1 Procedure  
Weigh accurately about 5 g of the prepared sample material in a moisture dish, about 6 cm to 8 cm in 
diameter and about 2 cm to 4cm in depth. Dry in an air oven at a temperature of 105 °C ± 2 °C to consta nt 
mass (within ± 5 mg).  
A.2 Calculation  
The m oisture and volatile matter  content shall be calculated as follows:  
Moisture and volatile matter, % by mass  = 
21x100
MM  
where  
M1 is the loss in mass , in grams,  on drying, and  
M2 is the mass , in grams,  of the material taken for test.  
 EAS 337: 2013 
6 © EAC  2013 – All rights reserved  
 Annex B  
(normative)  
 
Determination of cold water extract  
B.1 Procedure  
Weigh to the nearest 0.001 g, about 2 g of the prepared sample. Transfer the material quantitatively with 
water to a 100 -mL volumetric flask and fi ll to the mark with cold water. Stopper the flask and shake at 
approximately 30 min intervals for 8 h and allow to settle for another 16 h without shaking. Filter the extract 
through a dry filter paper. Reject first few millilitres, then evaporate a 25 - mL aliquot to dryness in a tared dish 
on the water -bath and heat in the oven at 100 °C ± 2 °C to constant mass. Record the final mass.  
B.2 Calculation  
The cold water soluble extract  content shall be calculated as follows:  
Cold water soluble extract, % by mas s =
12100x x4
MM  
where  
M1 is the mass , in grams,  of the text sample, and  
M2 is the mass , in grams,  of the residue obtained.  
 EAS 337: 2013 
© EAC 2013 – All rights reserved  7 
 Annex C  
(normative)  
 
Determination of crude fibre  
C.1 Reagents  
C.1.1  Petroleum ether , low boiling  range  of 40  C - 60 C  
C.1.2  Dilute sulphuric acid , 1.25 % ( v/v), accurately prepared  
C.1.3  Sodium hydroxide solution , 1.25 % (m/v), accurately prepared   
C.1.4  Ethyl alcohol , 95 % (v/v)  
C.2 Procedure  
Weigh accurately about 2.5 g of the prepared sample. Transfer the material int o 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 material and immediately connec t the flask with a water -cooled reflux condenser and heat, so that 
the contents of the flask begin to b oil within 1 min. Rotate the flask frequently, taking care to keep the material 
from remaining on th e sides of the flask and out of contact with the acid. Continue boiling for exactly 30 min.  
Remove th e flask and filter t hrough fine linen about 18 threads to the centimetre or through a coarse acid -
wash ed, hardened filter paper, held in a funnel, and wash with boiling water until the washings are no lo nger 
acid to litmus. Bring some quantity of sodium hydroxide solution to boil under a reflux condenser.  Wash the 
residue on the filter into the flask with 200 mL of boiling sodium hydroxide solution. Imme diately connect the 
flask with the reflux condenser. Immediately connect the flask with the reflux co ndenser and boil for exa ctly 30 
min. Remove the flask and immediately filter through the linen or t hrough filter paper.  
Thoroughly wash the residue with boiling water and transfer to a Gooch crucible p repared with a thin but 
compact layer of ignited asbestos. Wash the residue th oroughly first with hot water and th en with about 15ml 
of ethyl alcohol and with three successive washings of 15 mL o f petroleum ether each. Dry the Gooch crucible 
and contents at 105 C ± 1 C in an air - oven for 3 h , cool and weigh. Repeat the process of  drying for 30 min, 
cooling and weighing until the dif ference between two consecutive weighings is less than 1 mg. Incinerate the 
contents of the Gooch cr ucible in the muffle furnace at 550 C ± 20 C until all the carbonaceous matter is 
burnt. Cool the Go och crucible containing the ash in a desiccator and weigh.  
C.3 Calculation  
The crude fibre  content shall be calculated as follows:  
Crude fibre, % by mass =  
MM M ) 100(2 1  
where  
M1 is the mass, in g rams , of Gooch crucible and contents before ashing ; 
M2 is the mass, in g rams , of Gooch crucible and contents after ashing ; and  
M is the mass of the material taken for the test.  EAS 337: 2013 
8 © EAC  2013 – All rights reserved  
 Annex D  
(normative)  
 
Determination of mineral matter  
D.1 Procedure  
Weigh accurately about 5 g of the prepared sample in a silica dish.  
Heat the dish at first on a low flame and then in a muffle furnace maintained at about 600 C. Cool in a 
desiccator and weigh. Repeat the process of heating, cooling and weighing until constant mass is obtained. 
Preserve the ash for test under Annex E. 
D.2 Calculation  
The mineral matter  content shall be calculated as follows:  
Mineral matter, % by mass =
12x100
MM  
where  
M2 is the mass , in grams,  of the ash, and  
M1  is the mass in g rams,  of the material taken for the test.  
 EAS 337: 2013 
© EAC 2013 – All rights reserved  9 
 Annex E  
(normati ve) 
 
Determination of acid insoluble ash  
E.1 Reagent  
Dilute hydrochloric acid , approximately 5 N.  
E.2 Procedure  
To the ash preserved in D.1 add 25 m L of dilute hydrochloric acid (5  N), heat on water -bath for 10 min, allow 
to cool and filter the contents of  the dish through Whatman filter paper No. 42, wash the filter with distilled 
water till the washing is free from acid. Return the filter and residues to the dish.  
Keep it in oven to dry and ignite to free from carbon (in muffle furnace to 600 C). Cool th e dish in desiccator 
and weigh. Repeat the process of igniting, cooling and weighing, until the difference between two successive 
weighings is less than one milligram. Note the lowest mass.  
E.3 Calculation  
The acid insoluble ash  content shall be calculated  as follows:  
Acid insoluble ash, % by mass =
12x100
MM  
where  
M2 is the mass , in grams,  of the residue, and  
M1 is the mass , in grams,  of the material taken for test in D.1 . 
 EAS 337: 2013 
10 © EAC  2013 – All rights reserved  
 Annex F  
(normative)  
 
Determination of extraneous sand  
F.1 Procedure  
Weigh 5 g of prepared sample and transfer to a beaker. Add about 100 m L of carbon tetrachloride and mix the 
contents intimately and allow to settle. The supernatant liquid is decanted and the residue again stirred with 
another 100 -mL portion of carbon tetrac hloride. This process is repeated till it is freed of all vegetable matter. 
Transfer the residue to a tared silica dish, ignite and weigh to constant mass.  
NOTE  That the residue has been freed from vegetable matter can be judged by the absence of formation  of light 
leafy scum on inside of the beaker when carbon tetrachloride evapor ates partially.  
F.2 Calculation  
The extraneous sand  content shall be calculated as follows:  
Extraneous sand =
12x100
MM  
where  
M2 is the mass , in grams,  of the sand, a nd 
M1 is the mass , in grams,  of the material taken for test  
 EAS 337: 2013 
© EAC 2013 – All rights reserved  11 
 Annex G  
(normative)  
 
Thin layer chromatographic (TLC) test for detection of extraneous dyes  
G.1 Preparation of plates  
Mix 10 g of the silica gel (of TLC grade, particle size 10 μm to 40 μm) with 20 mL of distilled water to  make a 
slurry and spread over glass plates to a depth of 250 microns. Activate the plates for 30 mi n, by keeping in an 
oven maintained at 105 °C. 
G.2 Preparation of sample  
Extract about 0.1 g of the prepared sample with 5 mL of chloroform and apply one drop of the extract  on the 
base line of the plate.  
G.3 Development of chromatogram  
Keep the prepared plates in a jar containing a mixture of chloroform: methyl ethyl ketone: glacial  acetic acid 
(5:4:1). Allow the solvent front to r un up to 15 cm (the time taken is about 3 h) at room temperature (25 C to 
30 C). Observe the spots obtained, under ultra violet light.  
G.4 Results  
G.4.1  The principal ingredients of genuine henna powder, namely Lawsone and chlorophyll will give  spots 
on the chromatogram as given below: Lawsone Reddish spot with Rf value approximately 0.4 Chlorophyll 
Greenish spot coincident with the liquid front. 
G.4.2  Any other spots on the chromatogram indicate extraneous dyes.  
G.4.3  For comparison, use a reference samp le prepared from standard henna powder.  
 
 EAS 337: 2013 
12 © EAC  2013 – All rights reserved  
 Annex H  
(normative)  
 
Determination of Lawsone pigment content  
H.1 Outline of method  
The pigment is extracted and the Lawsone content is determined by comparing the observed optical density 
(measured colorimetricall y) with a calibration curve, relating optical density to various concentrations of 2 -
hydroxy -1,4-naphthoquin one. 
H.2 Apparatus  
Spectrophotometer or photoelectric colorimeter , with a filter of 490 nm  
H.3 Reagents  
H.3.1  Sodium bicarbonate solution , 5 % (m/v)  
H.3.2  2-Hydroxy -1,4-naphthoquinone  
H.4 Procedure  for preparation of Standard Calibration Curve  
H.4.1  Construct a calibration curve by dissolving known amounts of 2 -hydroxy -1,4-naphthoquinone 
(C10H6O3) varying in concentration from 0 % to 2 % under the sam e condition as described in H.4.2 below.  
H.4.2  Weigh 2.0 g of the prepared sample. Transfer it to a 100 -mL volumetric flask. Add 5 % (m/v) solution 
of sodium bicarbonate and make up the volume to mark. Shake the contents of the flask every half an hour or 
so for about 8 h. Allow to settle overnight, there -after filter the solution through a filter paper and reject the first 
few millilitre . Take 10 m L of the filtrate in a 25 -mL volumetric flask and dilute with distilled water up to the 
mark. Measure the opti cal density of this solution with a spectrophotometer at 490  nm. 
H.5 Calculation  
Refer to the calibration curve and determine the percent lawsone content of the sample from the curve.  
 EAS 337: 2013 
© EAC 2013 – All rights reserved  13 
 Annex I  
(normative)  
 
Determination of fineness  
I.1 Reagent  
Denatured sp irit, filtered  
I.2 Procedure  
Place about 10 g of the sample, accurately weighed, in the specified sieve and wash by means of a low 
stream of running tap water and finally with fine stream from a wash bottle until, as much material as would 
pass through the  sieve has passed. In case the material is not easily wetted by water, the washing could be 
started with a slow stream of filtered denatured spirit. Let the water drain from the sieve and then dry the sieve 
containing the residue on a steam bath. Transfer the residue onto a tared watch glass carefully and dry it to 
constant mass at 105 °C ± 2 °C. 
I.3 Calculation  
The material retained on the specified sieves  content shall be calculated as follows:  
Material retained on the specified sieves =
21x100
MM  
where  
M1 is the mass , in grams,  of the residue retained on the specified sieve and  
M2 is the mass , in grams,  of the sample taken for test.  
 
 EAS 337: 2013    
 
© EAC 2013  – All rights reserved