KENYA STANDARD   
 
 
                                                                                                 3004:2024  
FIRST EDITION  
 © KEBS 2023   
 Pyrethrum Refined Extracts - Specification  
 
 
 
  DKS 3004 :2024  
FIRST EDITION  
 
 
 TECHNICAL COMMITTEE REPRESENTATION  
The following organizations were represented on the Technical Committee:  
BASF  EA LTD  
Ecolab Kenya . 
Agrochemicals compan y. 
Competition Authority Kenya.  
Consumer Information Centre . 
Osho Chemical Industries Ltd  
University of  Nairobi  
Pest Control Product Board.  
Pyrethrum Processing company of Kenya.  
Agrochemical Association of Kenya.  
Agricul ture and food Auth ority.  
SC JOHNSON AND SON LTD.  
National Public Health Laboratory.   
Government Chemists  
Kenya Bureau of Standards — Secretariat  
 
REVISION OF KENYA STANDARDS  
In order to keep abreast of progress in industry, Kenya Standards shall be regularly reviewed.  Suggestions for 
improvements to published standards, addressed to the Managing Director, Kenya Bureau of Standards, are 
welcome.  
© Kenya Bureau of Standards  2023  
Copyright. Users are reminded that by virtue of Section 25 of the Copyright Act, Cap. 130 of 2001 of  the Laws of 
Kenya, copyright subsists in all Kenya Standards and except as provided under Section 25 of this Act, no Kenya 
Standard produced by Kenya Bureau of Standards may be reproduced, stored in a retrieval system in any form 
or transmitted by any mea ns without prior permission in writing from the Managing Director.  
  KENYA STANDARD  DKS 300 4:2024  
FIRST 
EDITION  
 
 
 
 Pyrethrum Refined Extracts - Specification  
 
  Kenya Bureau of Standards, Popo Road, Off Mombasa Road,  
P.O. Box 54974 - 00200,  Nairobi, Kenya  
 +254 020 6948000, + 254 722202137, + 254 734600471  
 info@kebs.org  
 @KEBS_ke  
 Kenya  bureau of standards (kebs)  
DKS 3004 :2024  
FIRST EDITION  
 
 
 Foreword  
 
This Draft Kenya  Standard is being developed by the Technical Committee  on pesticides under guidance of the 
Standard projects committee, and it is in accordance with the procedures of the  Kenya  Bureau  of Standards . 
 
This Draft Kenya  Standard is the first edition of Pyrethrum  refined  Extracts – Specification.  
This Draft  Kenya Standard  has been  prepared  with assistance  drawn  from the following  documents:  
IS 1051:1980 (Reaffirmed 2017) Specification for Pyrethrum Extracts, published by India Bureau of Standards . 
TBS/CDC 8 (441) DTZS Pyrethrum Extracts - Specification . 
 WHO/SIT/7. R3 (AUG 2009)  
The assistance obtained from the above source is hereby acknowledged with thank s. 
 
 
 
   DKS 3004:2024  
FIRST EDITION  
  
 
 
 Pyrethrum Refined Extracts –Specification  
 
1. Scope  
This Draft Kenya  Standard specifies the requirements, sampling and test methods of pyrethrum  refined  extracts 
containing  varying percentages of total pyrethrins . 
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 reference d document (including any amendments) applies.  
 
 ASTM D 92, Standard test method for flash and fire points by Cleveland open cup  
ASTM D 445, Standard test method for kinematic viscosity of transparent and opaque liquids  
ASTM D4052, Standard test method for density and relative density of liquids by digital density meter  
ISO13736 Determination of flash point – Abel closed – cup method.  
CIPAC MT 3.2.1  - Specific gravity, density and weight per millilitre . 
KS ISO 760:1978  Determination of water — Karl Fischer method (General method).  
KS EAS 123:2022 Distilled water — Specification . 
 
 
 
 
 
 
 
 
 
 DKS  3004 :2024  
FIRST EDITION  
 
 
  
 
3.Terms and definitions  
For the purposes of this standard the following terms and definitions shall apply.  
3.1 Pyrethrum   
aromatic plant of the daisy family, typically having feathery foliage whose brightly coloured aromatic flower heads 
contain pyrethrins as the active compounds.  
3.2 pyrethrum extracts  
product in the form of solution prepared by extracting pyrethrum flowers (Chrysanthemum cinerariifolium ) or 
(Chrysanthemum cinarariaefolium)  
3.3 Pyrethrin  
six naturally occurring isomers found in the flower of Chrysanthemum cinerariifolium as esters of pyrethric acid 
(pyrethrin -II, cinerin -II, and jasmolin -II) and chrysanthemic acid (pyrethrin -I, cinerin -1 and jasmolin -I) that have 
insecticidal property.  
 
 
4. REQUIREMENTS . 
4.1 General requirements  
4.1.1  The active ingredients in pyrethrum extract shall be composed of six esters, namely, pyrethrin I &II, 
cinerin I &II and jasmolin I &II. (See Annex B)  
4.1.2  The material shall be an extract of pyrethrum flowers (Chrysanthemum cinerariifolium) or  
(Chrysanthemum cinarariaefolium).  
4.1.3  The material shall be homogeneous  viscous  liquid . 
4.1.4  Sediment and/or suspended matter shall be negligible.  
4.1.5  It shall be free from synthetic pyrethroids.  
4.1.6  It shall be free from other synthetic pesticide residues.  
4.1.7     The mate rial shall b e greenish yellow  to brown in colour and posses the characteristic  odour of the  
commercial pyrethrum flowers . 
4.1.8    Shall  not contain traces of the solvents used during extraction.  DKS 3004: 2024  
FIRST EDITION  
 
 
 4.2 Specific requirements  
4.2.1  Pyrethrum extracts shall conform to the specific requirements given in Table 1  
 
SL. No Characteristic  Requirement  Test method  
i) Flash  Point.  min 32°C  KS ISO 13736  
 
ii) Volatiles  level,  %. max 1.0  ASTM D5191  
iii) Specific  gravity  at 15  ºC, min. 0.91  ASTM  D 4052/IP  
365  
 CIPAC MT 3.2.1  
 
iv) Total  pyrethrin  content, %  min 25   
Annex C  
 
v) Viscosity,  cPs,at  23 °C, min/ 4000  ASTMD 445  
vi) Moisture conte nt % max  1.0 KS ISO 760 
vii) PH, %   1.0  
Annex D  
viii) Optical density  0.9  Annex  E 
ix Matter insoluble in dichloromethane   -  Annex  F 
 
 5. Packaging and Marking  
5.1. Packaging  
5.1.1  The material shall be packed in clean, dry and leak proof containers made of mild steel or tinplate. Other 
non-corrosive/non -reactive, opaque containers may also be used. They shall be sealed air -tight after filling.   
 
5.2 Marking  and labelling.  
5.2.1 The container shall be legibly and indelibly marked in accordance with the Pest Control Products Act Cap 
346 Laws of Kenya (Herein “the Act”). The information on each package and/or on every label and leaflet shall 
be printed in both English and Kiswahili. The information shall be indelibly and legibly marked on a label.  The 
following is the information that must appear and how it should appear on the display panels.  
A) Primary display panel  
i) - Trade name of the products  
-  Its physical form  
-  Purpose of use  DKS  3004 :2024  
FIRST EDITION  
 
 
 ii) Statement “READ THE LABEL BEFORE USING” Must appear prominently in capital letters.  
iii) Statement “KEEP LOCKED OUT OF REACH OF CHILDREN” to appear prominently in capital 
letters.  
iv) Class designation – must appear in capital letters as follows:  
a. DOMESTIC CLASS  
v) Nature and degree of hazard inherent in the pest control product and shown by a precautionary 
symbol and signal word.  
vi) REGISTRATION NO. PCPB(CR) to appear prominently and distinctly . 
vii) Net content  
viii) Name and address of Registrant, Local Agent, Manufacturer, or Distributor  
ix) Date of Manufacture, Batch No. & Expiry date that does not have to be printed.  
x) Shelf life in an original  unopened container.  No Maximum or Minimum shelf -life period should 
appear  
xi) Pictograms and Color Codes.  
 
B) Secondary display panel  
(i) A brief description of the product.  
(ii) Directions of use that must include dosage, rate in the amount of formulation per unit area and the 
spray volume.  
(iii) Significant hazards respecting handling, storage, and procedures to alleviate the hazards.  
(iv) Decontamination procedures  
(v) Disposal of product and empty containers  
(vi) Significant hazards to the public health and environment and how to alleviate such hazards.  
(vii) FIRST AID INSTRUCTIONS – in capital letters.  
(viii) TOXICOLOGICAL INFORMATION/NOTICE TO DOCTOR.  
(ix) NOTICE TO USER* - To appear as stated in the Act  
(x) SELLERS GUARANTEE* – To appear as stated in the Act . 
(xii)   To be stored at room temperature.  
 
6. Sampling  
6.1. Representative samples of the material shall be drawn as prescribed in the Annex A.   
6.2. Tests shall be carried out by the appropriate method referred to under 4.2.1.  
 
6.3. Quality of Reagents  
Unless specified otherwise, analytical grade chemicals and distilled water complying with KS EAS 123:2022 (see 
Clause 2) shall be used . 
NOTE : Analytical grade  chemicals  shall mean  chemicals  that do not contain  impurities  which  will affect  the results  
of analysis.  DKS 3004: 2024  
FIRST EDITION  
 
 
  
Annex  A 
(Normative)  
SAMPLING  OF PYRETHRUM  EXTRACTS  
A.1 GENERAL  PRECAUTIONS  
A1.0 In drawing,  preparing,  storing  and handling  test samples,  the following,  precautions  and directions  
shall        be observed.  
A1.1  Samples  shall not be taken  in exposed place . 
A1.2 The sampling  equipment  shall be clean  and dry when  used . 
A1.3 Precautions shall be taken to protect the samples, the material being sampled, the sampling equipment  
and the containers  for samples  from adventitious  contamination.  
A1.4 To draw a representative sample, the contents of  each container selected for sampling  shall be 
mixed  as thoroughly  as possible  by shaking  or stirring  or both,  by suitable  means  or by rolling  so as to 
bring  all portions  into uniform  distribution  (See  A. 3.3.1).  
A1.5 The samples shall  be placed  in suitable, clean,  dry and  air-tight amber colored glass, containers, on  
which  the material  has no  action.  
A1.6 The sample container shall be of such as size that they are almost, but not completely, filled by 
the sample.  
A1.7  Each  container  shall be closed  tightly  with a stopper  after filling  and marked  with full details  of 
sampling,  the date of manufacture,  name  of the manufacturer  and other  particularities  of the 
consignment.  
A1.8 Sample shall be stored in such a manner that the temperature of the material does not vary unduly 
from the normal  temperature.  It should  preferably  be refrigerated  at 0OC or below.  
 
A.2 SAMPLING  TUBE  
 
A2.1 A pipette  of convenient  volume  may be used  for drawing  the sample.  
A.3 SCALING  OF SAMPLING  
A3.1  All the containers in a single consignment of the material drawn from the same batch of manufacture shall 
constitute a lot. If a consignment is declared or is known to consist of different batches these shall be grouped 
together and each such, group shall constitute a separate Iot.  
A3.2 Samples  shall be tested  for each  lot for ascertaining  the conformity  of the material  to the requirement   of 
the specification.  
A3.3 The number  (n) of containers  to be chosen  from the lot shall depend  on the size of the lot and shall be 
in accordance  with col 1 and 2 of Table  1. 
A3.4 These containers shall be chosen at random from the lot and in order to ensure that randomness of  
selection,  some  random  number  table,  as agreed  to between the  purchaser  and the vendor,  shall be used.  
In case  such  a table  is not available,  the following  procedure  shall be adopted.  DKS  3004 :2024  
FIRST EDITION  
 
 
 A3.5 Starting from any container in the lot, count them as 1, 2, 3 .  etc, up to r in a systematic  manner,  
where  r is equal  to the integral  part of the value  of N/n. N being  the total number  of containers  in the lot and n 
the number of containers to be chosen (see Table 1). Every rth container thus counted shall be  separated  
until the requisite  number  of containers  is obtained  from the lot to give samples  for test. 
TABLE  1 Number  of containers  to be chosen  for sampling  (clauses  A-3.3.1,  A-3.2, A-4.1 and A-4.3) 
 
Lot size No. of containers  to be chosen  
N(1) n(2) 
3 to 15 3 
16 to 40 4 
41 to 65 5 
66 to 110 7 
Over  110 10 
 
A.4 TEST  SAMPLES  AND  REFERENCE  SAMPLES  
A4.1 Before  drawing  the test sample,  mix thoroughly  the contents  of each  container  selected  (see Table  1) 
by shaking or stirring by suitable means or by rolling. Draw, by inserting the pipette through the bung  
hole or any other convenient opening, small portions of the material from different parts of each container  
selected.  The total quantity  of the material  drawn  from each  container shall  be sufficient to  conduct  the 
tests  for all the characteristics  given  in 4.1 and 4.2. 
A4.2 Mix thoroughly all portions of the material drawn from the same  container. Out of these portions, a small  but 
equal quantity shall be taken for each selected container and shall be well mixed together so as to  form 
a composite sample of not less than 200ml. This composite (sample shall be divided into three  equal  
parts,  one for the purchaser,  another  for the vendor  and the third for the referee.  
A4.3 Referee samples - Referee samples shall consist of the composite sample (see A -4.2) marked for this  
purpose  and shall bear the identification  mark  of the purchaser  and the vendor.  These  shall be kept at a 
place  agreed  to between  the two. 
 
 
A.5 NUMBER  OF TESTS  
A A5.1 Tests for the determination of total pyrethrin content of the material shall be conducted on composite  
samples.  (See A4.2).  
B A5.2 Test for the  determination  of the remaining characteristics namely,  colour  and odour  and flash  point 
shall be conducted  on the composite  sample  as prepared  under  A-4.2 
 
 
 
 
 DKS 3004: 2024  
FIRST EDITION  
 
 
 Annex  B 
(Normative)  
 
IDENTITY  TEST  FOR  PYRETHRINS  
B.0 PRINCIPLE  
B.0.1  HPLC  Method  of analysis  for pyrethrins  
 
B.1 APPARATUS  
B.1.1  High pressure  liquid  chromatograph  equipped  with a C-8 reverse  phase  column  (Agilent  Eclipse  XDB,  5 
micron),  4.6 mm id. x 150 mm length  or (equi valent coloum)  and a UV detector . 
B.2 REAGENTS  
 
B.2.1  Acetone  – UV Grade  
 
B.2.2  Methanol  – UV Grade  
 
B.3 HPLC  Conditions  
 
B.3.1  Mobile  phase : 85 % Methanol/  15 % water  
 
B.3.2  Flow  rate: 1.0 ml/min  
 
B.3.3  Wavelength:  225 nm 
 
B. 4 STANDARD  PREPARATION  
 
B.4.1  weigh  out the following  standard  amount  into a 100 ml volumetric  flask.  
 
B.4.2  add 5.0 mls acetone,  mix and bring  to volume  with methanol.  
 
Active  MG.(  actual)  
 
Pyrethrum  20% standard  100 ( 20 mg PY’s)  
 
B.4.3  a well-established  standard  quantitated  using  official  AOAC  Mercury  reduction  methodology  should       
be used  qualified  standards  solution  may be supplied  as needed  by the manufactu rers. 
 
B.5 SAMPLE  PREPARTION  
 
B.5.1 weigh  out sample  equivalent  of 20 mgs of pyrethrins  into a 100 ml volumetric.  DKS  3004 :2024  
FIRST EDITION  
 
 
  
B.5.2 add 5.0 mls acetone,  mix and dilute  to 100 mls with methanol . 
 
B.6 HPLC  INJECTION  PROCEDURE  
 
B.6.1 inject 5 µ l of standard solution into HPLC instrument until acceptable reproducibility is obtained.  
Inject  sample  solution  in the same  manner.  Use peak  area or height  for calculation.  The pyrethrin  II’s are 
calculated using the sum of the two peaks at 2.9 and 3.4 minutes. The pyrethrin I’s are calculated using  
the sum of the two peaks  at 4.8 and 5.9  minutes.    
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 DKS 3004: 2024  
FIRST EDITION  
 
 
 Annex  C 
(Normative)  
DETERMINATION  OF TOTAL  PYRETHRIN  CONTENT  
C.0 PRINCIPLE  
C.0.1  The pyrethrins  after extraction  are hydrolysed  to chrysanthemum  mono - and dicarboxylic  acids.  
Monocarboxylic  acid from 'Pyrethrin  I, after extraction  is reacted  with Deniges  reagent  and mercurous  sulphate 
formed is titrated with potassium iodate. Dicarboxylic acid from Pyrethrin II, remaining after  the extraction of  
monocarboxylic  acid is  extracted  and titrated with  standard  sodium  hydroxide . 
 
C.1 REAGENTS  
C.1.1 Deniges Reagents - Mix 5 g yellow mercuric oxide with 40 ml water, and while stirring, slowly  
add 20 ml sulphuric acid, then add additional 40 ml water and stir until all dissolves. Test for the  
absence of mercurous mercury by adding a few drops of iodine monochloride solution to 10 ml and  
titrating with  potassium  iodate  standard  solution  as in B.2.2.  
 
C.1.2 Iodine Monochloride Solution - Dissolve 10 g potassium iodide and .6.44 g potassium iodate in  
75 ml water in glass stoppered bottle, add 75 ml hydrochloric acid and 5 ml chloroform and adjust to  
faint iodine colour (in chloroform) by adding dilute potassium iodide or potassium iodate solution. If  
much iodine is liberated, use stronger solution of potassium iodate than 0.01 M at first, making final  
adjustment with 0.01 M solution. Keep in dark and readjust when necessary. It should not be stored  
in refrigerator.  
C.1.3 Potassium  Iodate  Standard  Solution  - 0.01 M, Dissolve  2.14 g pure potassium  iodate,  previously  
dried at  105°C,  in water  and dilute  to one litre.  One ml of solution  = 0.0057  g pyrethrin I.  
C.1.4 Alcoholic  Sodium  Hydroxide  Solution -1 Nand  0.5 N 
C.1.5 Petroleum  Ether  - aromatic  free, boiling  range  40-60°C  or 60 -80°C  
C.1.6 Ethyl  Ether  -peroxide  free 
C.1.7 Sodium Hydroxide  Standard  Solution  – 0.02 N 
C.1.8 Filter  Cel 
C.1.9 Barium Chloride  Solution  -10 percent  (m/v).  
C.1.10 Dilute  Sulphuric  Acid -1: 4 (vlv). 
C.1.11 Ethyl Alcohol -95 percent  (vlv) and 99 percent  (vlv),  anhydrous  
C.1.12 Sodium  Chloride  - solid as well  as saturated  solution,  
C.1.13 Chloroform  
 
C.1.14 Dilute  Hydrochloric Acid -3: 2 (v Iv), 
C.1.15 Phenolphthalein  Indicator  Solution  - one percent  (m/v)  in ethyl  alcohol.  DKS  3004 :2024  
FIRST EDITION  
 
 
 C.2 PROCEDURE  
C.2.0  Weigh sample containing 40 -150 mg total pyrethrins, add 50 ml petroleum ether and I g filter  
cell, and place in refrigerator at 0 ± 0.5°C overnight. Filter through Gooch filter into 300 ml Erlenmeyer flask  
and wash  with three  15 ml portions  of cold petroleum  ether,  evaporate  filtrate  and washings  on water  
bath, using  air current  until the petroleum  ether is  almost  entirely  removed.  
C.2.1  Add 20 ml 1 N alcoholic sodium hydroxide, or more,  if necessary, to extract pyrethrins, connect 
to reflux condenser, and boil gently for 60 to 90 minutes. Transfer to 600 -ml beaker and add enough 
water  to make aqueous layer 200 ml. If more than 20 ml alcoholic sodium hydroxide solution was used, 
add enough  water  so that all alcohol  is removed  when  volume  is reduced  to 150 ml. Add few glass  
beads  and boil aqueous layer down to 150 ml. Transfer to 500 -ml separator and drain aqueous layer 
into 250 -ml volumetric flask. Wash oil layer once with water and add washings to aqueous portion. If 
slight emulsion  still persists after draining aqueous layer and washings, add two to three ml 10 percent 
barium chloride  solution but do not shake vigorously after adding barium chloride, because reversed 
emulsion difficult to  separate may form. To aqueous solution in 250 -ml flask add I g filter cel and 
approximately 10 ml of the  barium chloride solution, swirl gently and let stand for 30 minutes. Dilute 
to volume; mix thoroughly and  filter off 200 ml. Test filtrate  with barium  chloride  solution  to see if enough  
has been  added  to obtain  clear  solution. Neutralize with sulphuric acid (1:4), using 1 drop 
phenolphthalein and add 1 ml excess. (If necessary  to hold solution  overnight  at this point,  leave  in 
alkaline  condition.)  
C.2.2  Determination of Pyrethrin  I - Filter acid solution from C.2.1 through 7 cm paper, coated lightly with  
suspension  of filter  cell in water,  on buchner,  and wash with  three  15 ml portions  of water.  Transfer  to 500- 
ml glass stoppered separator and extract with two 50 ml portions petroleum ether. Shake each extract  
approximately for one minute, releasing pressure,  if necessary,  by inverting separator and carefully venting  
through stopcock. Let layers separate for approximately five minutes or until aqueous layer is clear before  
draining  and re-extraction,  Reserve  aqueous  layer  for pyrethrin  II determination.  Do not combine  petroleum  
ether  extracts  but wash  each  in sequence  with same  three  10 ml portions  water, and  filter petroleum  ether  
extracts  through  small  cotton  plug,  into a clean  250-ml separator.  Wash  separators  and cotton  in sequence  
with 5 ml petroleum ether. Extract combined petroleum ether solutions with 5 ml 0.1 N sodium hydroxide,  
shaking vigorously for approximately one minute. Let layers separate for approximately 5 minutes before  
draining  aqueous  layer  into I00-ml beaker.  Wash  petroleum  ether  with additional  5-ml portion  0.1 N sodium  
hydroxide and with 5 ml water, adding washings to beaker. Add 10 ml Deniges reagent and let stand in  
complete darkness for one hour at 25 ± 2° C. Add 20 ml alcohol and precipitate mercurous chloride with 3  
ml saturated sodium chloride solution. Warm to approximately 60°C and let stand several minutes until  
precipitate  coagulates  and settles.  Filter  through  small  paper,  transferring  all precipitate  to paper,  and wash  
with approximately 10 ml hot alcohol. Wash with 2 or more 10 ml portions hot chloroform and place paper  
and contents  in 250-ml glass  stoppered  conical  flask.  Add 50 ml cooled  dilute  hydrochloric  acid (3: 2). Add 
5 ml chloroform  and 1 ml freshly  adjusted  iodine  monochloride  solution  and titrate  with standard  potassium  
iodate solution, shaking vigorously approximately 30 second after each addition, until no iodine colour  
remains in chloroform layer. Take as end point when red colour disappears from solvent layer and does  
not return within three minutes. From standard potassium iodate solution used in titration and blank on  
Deniges  reagent,  calculate  percent  pyrethrin  I. 
 DKS 3004: 2024  
FIRST EDITION  
 
 
 C.2.3  Calculation  -1 ml of 0.01 M KIO3= 0.005  7 g pyrethrin  I. 
NOTE - Chrysanthemum monocarboxylic acid reacts with Deniges reagent to form series of colours  
beginning with phenolphthalein red, which gradually changes to purple, then to blue and finally to bluish  
green. Colour reaction is very distinct with 5 mg monocarboxylic acid and amounts as low as 1 mg can  
usually be detected. Therefore, no pyrethrin I should be reported if colour reaction is negative. With  
samples containing much perfume or other saponifiable ingredients, it may be. necessary to use as much  
as 50 ml 1 N alcoholic sodium hydroxide. When lethanes are present, after washing mercurous chloride  
precipitate  with alcohol  and chloroform,  wash  once  more  with alcohol  and then several  times  with hot water.  
 
C-2.4 Determination  of Pyrethrin  II - If necessary,  filter aqueous  residue  reserved  in C.2.2  from petroleum  
ether extract through Gooch. Concentrate filtrate to approximately 50 ml and transfer to 500 -ml glass  
stoppered  separator.  Wash  beaker  with three  15 ml portions  water.  Acidify  with 10 ml hydrochloric  acid and 
saturate with sodium chloride. (Acidified aqueous layer must contain visible sodium chloride crystals  
throughout  following  extractions.)  
Extract with 50 -ml ether, drain aqueous layer into second separator and extract again with 50 ml ether.  
Continue  extracting  and draining  aqueous  layer,  using  35 ml for third and fourth  extractions.  Shake  each  
extract for approximately one minute, releasing pressure, if necessary, by inverting separator and  carefully 
venting through stopcock. Let layers separate for approximately five minutes or until aqueous  layer is clear 
before subsequent draining and extraction. Combine ether extracts, drain and wash with  three  10 ml 
portions  saturated  sodium  chloride  solution.  Filter  ether  extracts  through  cotton  plug into 500- ml conical flask 
and wash separator and cotton with additional 10 ml ether. Evaporate ether on water  bath and  remove  any 
fumes  of hydrochloric  acid with air current  and continue  heating  for approximately  five minutes.  Dry for 10 
minutes  at 100°C.  Add 2 ml neutral  alcohol  and 20 ml water  and heat to dissolve  acid. Cool, filter through 
Gooch,  if necessary, add two drops phenolphthalein and titrate with 0'02 N sodium hydroxide. Check 
normality of 0'02 N sodium hydroxide on the same day, as the sample is  titrated.  
 
 
 
 
 
 
 
 
 
C.2.5  Calculation  
1 ml of 0.02  N NaOH =  0.00374  g pyrethrin  II. 
 
Total  pyrethrin  shall be  obtained  by adding  pyrethrin  I and pyrethrin  II 
Note:  Total  pyrethrin  should  be in percentage  (w/w)  DKS  3004 :2024  
FIRST EDITION  
 
 
 Annex  D 
(Normative)  
 
DETERMINATION  OF PH 
D.1 Apparatus  
A pH Electrode System such as a single or dual glass electrode system conditioned and maintained according to 
the manufacturer’s instructions.  
D.2 Reagents  
Freshly distilled/deionized water free from accumulation of CO2 from the atmosphere.  
D.3 Procedure  
Prepare 1 % solution of the extract by weighing 1.0 g of sample into a calibrated beaker. Add 50 mL  
Distilled water or equivalent neutral organic solvent such as ethanol. Top up reagent water to 100 mL, mix 
vigorously using magnetic stirring rod until the formulation is completely . 
Mixed or dispersed.  
Prior to pH measurement, calibrate the pH -meter using a standard buffer  4, 7 and 10 but ensure that the 
temperature of the solution does not differ from the reference solutions used for calibration. Rinse the cell several 
times with a small amount of the solution. Immerse the electrode into the solution and measure the pH wit hout 
stirring. Record the pH value after a stable figure is obtained.  
 
 
 
 
 
 
 
 
 
 
 
 DKS 3004: 2024  
FIRST EDITION  
 
 
 Annex  E 
(Normative)  
 
DETERMINATION  OF OPTICAL DENSITY  
E.1 General  
The natural colouring matter content of pyrethrum extract is extracted with mineral turpentine oil. The absorbance 
of the solution obtained is measured by using a UV -Visible Spectrometer at a wavelength of 435 nm.  
E.2 Apparatus  
A UC -visible Spectrophotometer suitable for measuring at a wavelength of 435 nm and having a band width of 2 
nm. 
A 20 mL volumetric flask  
Measuring Cylinder  
A pair of cuvettes  
E.3 Reagents  
Mineral turpentine oil of known purity.  
E.4 Procedure  
Measure and transfer exactly 1 mL of the pyrethrum extract in the 20 mL volumetric flask. Add to it mineral 
turpentine oil and make up the volume up to the mark. Shake the flask to mix the content thoroughly.  
Take a pair of clean cuvettes. Switch on the Spectrophotometer and set the wavelength at 435 nm. In one cuvette 
take the solvent and place this cuvette in the reference cell of the spectrophotometer. Take the diluted sample 
from the volumetric flask in the other cuvette and pl ace the cuvette in the sample cell of the spectrophotometer. 
Close the chamber and measure the absorbance at 435 nm.