PUBLIC REVIEW DRAFT DRAFT UGANDA STANDARD  
  DUS DEAS 455 
First  Edition  
2016-mm-dd 
 
 Reference number  
DUS DEAS 455: 2016 
© UNBS 201 6 
  
Long lasting insecticide treated mosquito nets — Specification  
 PUBLIC REVIEW DRAFTDUS DEAS 4 55:2016 
ii                © UNBS  2016  - 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 2016 
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 2 50/1/2/3 
Fax: 256 414 286 123 
E-mail: info@unbs.go.ug  
Web: www.unbs.go.ug  
 PUBLIC REVIEW DRAFTDUS DEAS 4 55:2016 
© UNBS  2016 - 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 Draft Uganda Standard, DUS D EAS 455: 2016, Long lasting insecticide treated mosquito nets — 
Specification,  is identical with  and has been reproduced from a Draft East African Standard , DEAS 455: 2016 , 
Long lasting insecticide treated mosquito nets — Specification,  and is being proposed for adoption as a 
Uganda Standard. 
This standard cancels and replaces US 307:2014, Mosquito nets — Specification , which has been technically 
revised.  
This standard was developed by the Subcommittee on Textiles and textile products (SC 1) under the Textiles, 
leather, paper and related products’ Standards Technical Committee (UNBS/TC 7).  
Wherever the words, “ East Afric an Standard" appear, they should be replaced by "Uganda Standard." 
 
   DEAS 455: 2016  
ICS 59.080.30  
© EA C 2016                                                                                                                        Second Edition 2016   
 
DRAFT EAST AFRICAN STANDARD  
Long lasting insecticide treated mosquito nets — Specification   
EAST AFRICAN COMMUNITY  EAS 455: 2016  
ii © EAC 2016  – All rights reserved  
 Copyright notice  
This EAC document is copyright -protected by EAC. While the reproduction of this document by 
participants in the EAC standar ds development process is permitted without 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 permissi on to reproduce this document for the purpose of selling it should be addressed 
as shown below or to EAC’s member body in the country of the requester:  
© East African Community 2016  — All rights reserved  
East African Community   
P.O.Box 1096  
Arusha  
Tanzania  
Tel: 255 27 2504253/8  
Fax: 255 27 2504481/2504255  
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 455: 2016  
© EAC 2016  – All rights reserved  iii 
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ .............................  v 
1 Scope  ................................ ................................ ................................ ................................ ......................  1 
2 Normative refe rences  ................................ ................................ ................................ ............................  1 
3 Terms and definitions  ................................ ................................ ................................ ...........................  2 
4 Requirements  ................................ ................................ ................................ ................................ .........  3 
4.1 Fibre  ................................ ................................ ................................ ................................ ........................  3 
4.2 Active ingredients for nets treated after manufacturing  ................................ ................................ ... 3 
4.3 Shapes, sizes and dimensions  ................................ ................................ ................................ ............  5 
4.3.1  Shape  ................................ ................................ ................................ ................................ ......................  5 
4.3.2  Sizes and dimensions  ................................ ................................ ................................ ...........................  5 
.4.4 Manufacture and workmanship  ................................ ................................ ................................ ...........  6 
4.4.1  Construction  ................................ ................................ ................................ ................................ ..........  6 
4.4.2  Net attachments or tying tapes  ................................ ................................ ................................ ............  6 
4.4.3  Top support rin g ................................ ................................ ................................ ................................ .... 6 
4.4.4  Defects  ................................ ................................ ................................ ................................ ....................  6 
5 Packing and labelling  ................................ ................................ ................................ ............................  6 
5.1 Packing  ................................ ................................ ................................ ................................ ...................  6 
5.2 Labelling  ................................ ................................ ................................ ................................ .................  6 
7 Sampling  ................................ ................................ ................................ ................................ ................  7 
7.1 Lot ................................ ................................ ................................ ................................ ...........................  7 
7.2 Scale of sampling and testing  ................................ ................................ ................................ ..............  7 
Annex  A (normative)  Determination of Deltamethrin content in insecticide treated mosquito nets 
by High Performance Liqui d Chromatography  ................................ ................................ ..................  9 
Annex B (normative)  Determination of Permethrin content in insecticide treated mosquito nets .........  13 
Annex C (no rmative)  Determination of Alphacypermethrin content in insecticide treated 
mosquito nets  ................................ ................................ ................................ ................................ ...... 19 
Annex D (normative)  Determination of Piperonyl butoxide in polyethylene matrix by Gas 
Chromatograp hy ................................ ................................ ................................ ................................ .. 23 
D.1 Scope  ................................ ................................ ................................ ................................ ....................  23 
D.2 Outline of method  ................................ ................................ ................................ ................................  23 
D.3 Reagents  ................................ ................................ ................................ ................................ ..............  23 
D.4 Apparatus  ................................ ................................ ................................ ................................ .............  23 
D.5 Operating Procedure  ................................ ................................ ................................ ...........................  24 
D.5.1  Operating conditio ns (typical):  ................................ ................................ ................................ ..........  24 
D.5.2  Preparation of sample.  ................................ ................................ ................................ ........................  25 
D.5.3  System equilibration.  ................................ ................................ ................................ ..........................  25 
D.5.4  Determination.  ................................ ................................ ................................ ................................ ..... 25 
D.6 Calculation.  ................................ ................................ ................................ ................................ ..........  25 
Annex  E (normative)  Measurement of net dimensions  ................................ ................................ ...............  26 
D.1 Rectangular nets: Length, width and height  ................................ ................................ ....................  26 
D.1.1  Apparatus  ................................ ................................ ................................ ................................ .............  26 
D.1.2  Conditioning  ................................ ................................ ................................ ................................ ........  26 
D.1.3  Procedure  ................................ ................................ ................................ ................................ .............  26 
D.1.4  Calculation  ................................ ................................ ................................ ................................ ...........  26 
D.1.5  Repor t ................................ ................................ ................................ ................................ ...................  26 
D.2 Circular nets: Top ring diameter, bottom circumference and conical height  ...............................  26 
D.2.1  Apparatus  ................................ ................................ ................................ ................................ .............  26 EAS 455: 2016  
iv © EAC 2016  – All rights reserved  
 D.2.2  Conditioning  ................................ ................................ ................................ ................................ ........  26 
D 2.3  Procedure  ................................ ................................ ................................ ................................ ............  27 
Bibliography  ................................ ................................ ................................ ................................ .....................  28 
 EAS 455: 2016  
© EAC 2016  – 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 ba rriers 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 African 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 organizations. Draft East African Standards 
are circulated to stakeholders through th e 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 Community.  
East African Standards are subject to review, to keep pace with te chnological 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 455 was prepared by Technical Committee EAS/TC 061, Textiles and Textile Produ cts. 
This second edition cancels and replaces the f irst edition (EAS  455:2008 ), which has  been technically revised.  EAS 455: 2016  
vi © EAC 2016  – All rights reserved  
 Introduction  
This East African Standard specifies the requirements of two types of mosquito nets namely treated and 
untreated nets.  
Mosqui to nets which are available in the market can be categorised according to their sizes. In determining 
the quality of this widely used customer item, more emphasis should be given not only to the netting fabric but 
also to stitching and other attachments. I n that case shape, size and dimensions are very important. This East 
African Standard which outlines requirements for the manufacture and workmanship of mosquito nets will be 
the guidance for manufacturers and will protect the buyers.  
For the purpose of de ciding whether a particular requirement of this East African Standard is complied with, 
the final value, observed or calculated, expressing the result of a test or analysis shall be rounded off  in 
accordance with EAS 124 . 
The number of significant places r etained in the rounded off value shall be the same as that of the specified 
value in this East African Standard.  
In the preparation of this Standard assistance was drawn from the following publications:  
US 307: Mosquito Nets – Specifications  
KS 1305 -1, 2 S pecification for mosquito netting.  
Approved specifications published by World Health Organization  on long l  (WHO).  
 DRAFT EAST AFRICAN STANDARD  DEAS 455:2016  
 
© EAC 2016  – All rights reserved  1 
 Long lasting insecticide treated m osquito nets  — Specification  
1 Scope  
This Draft East African Standard prescribes the requirements and tes t methods for treated Long Lasting 
Insecticidal nets (LLIN).  
2 Normative references  
The following referenced documents are indispensable for the application of this standard . For dated 
references, only the edition cited applies. For undated references, the  latest edition of the referenced 
document (including any amendments) applies.  
EAS 124, Rounding off numerical values.  
EAS 237, Textiles — Determination of colour fastness — Colour fastness to washing — Test 3.  
EAS 258, Textiles — Determination of length a nd width of fabrics.  
ISO 105 -B01: Textiles — Tests for colour fastness — Part B01: Colour fastness to light: Daylight  
ISO 105 -B02: Textiles -- Tests for colour fastness -- Part B02: Colour fastness to artificial light: Xenon arc 
fading lamp test  
ISO 139, T extiles — Standard atmospheres for conditioning and testing  
ISO 13938 -1 Textiles — Bursting properties of fabrics — Part 1: Hydraulic method for determination of 
bursting strength and bursting distension  
ISO 13938 -2: Textiles -- Bursting properties of fabr ics -- Part 2: Pneumatic method for determination of 
bursting strength and bursting distension  
ISO 16663 -1: Fishing nets -- Method of test for the determination of mesh size -- Part 1: Opening of mesh  
ISO 1833 -1: Textiles -- Quantitative chemical analysis -- Part 1: General principles of testing  
ISO 1833 -11, Textiles — Quantitative chemical analysis — Part 11: Mixtures of cellulose and Polyester fibres 
(method using sulphuric acid)  
ISO 1833 -16, Textiles — Quantitative chemical analysis — Part 16: Mixtures o f polypropylene fibres and 
certain other fibres (method using xylene)  
ISO 1833 -2: Textiles -- Quantitative chemical analysis -- Part 2: Ternary fibre mixtures  
ISO 1833 -23 Textiles — Quantitative chemical analysis — Part 23: Mixtures of polyethylene and 
polypropylene (method using cyclohexanone)  
ISO 1833 -24 Mixtures of polyester and some other fibres( method using phenol and tetrachloroethane)   
2 © EAC 2016  – All rights reserved  
 ISO 2060, Textiles — Yarn from packages — Determination of linear density (mass per unit length) by the 
Skein method  
ISO 1833 -5: Textiles -- Quantitative chemical analysis -- Part 5: Mixtures of viscose, cupro or modal and 
cotton fibres (method using sodium zincate)  
ISO 3758  Textiles — Care labelling code using symbols  
ISO 3759: Textiles -- Preparation, marking and meas uring of fabric specimens and garments in tests for 
determination of dimensional change  
ISO 3801, Textiles — Woven fabrics — Determination of mass per unit length and mass per unit area  
ISO 3801, Textiles — Woven fabrics — Determination of mass per unit le ngth and mass per unit area  
ISO 5077,  Textiles — Determination of dimensional change in washing and drying  
ISO 6330,  Textiles — Domestic washing and drying procedures for textile testing  
ISO 8388: Knitted fabrics -- Types -- Vocabulary  
ISO/TR 11827:  Textil es -- Composition testing -- Identification of fibres  
ISO 6938:  Textiles -- Natural fibres -- Generic names and definitions  
ISO 2076:  Textiles -- Man-made fibres -- Generic names  
3 Terms and definitions  
For the purposes of this standard, the following term s and definitions  and those in ISO 6938  and ISO 2076 
shall apply  
3.1 
Long Lasting Insecticidal Nets (LLIN)  
factory treated mosquito net made with a netting material that has insecticide incorporated within the yarn or 
wound around the fibres  
3.2 
mono -treated nets  
finished net treated with a single active ingredient  
3.3  
combination nets  
finished  net treated with two or more active ingredients  
3.3 
active ingredients  
biologically active substance that forms part of the formulation mixture that are incorpo rated in LLIN as approved by 
World Health Organization or any other internationally recognized body  
 
3.4 
top ring  
used in conical nets and made of  non-corrosive , anti-rust and anti -buckling material, fixed to the  roof of the net  
 
3.5 
height  
the dimension  measured along a vertical seam from the top  to the bottom edge of the net  
  
© EAC 2016  – All rights reserved  3 
 3.6 circumference  
the perimeter of the net at its bottom edge  
 
4 Requirements  
4.1 Mono -treated nets  
4.1.1  Physical characteristics   
Long lasting insecticidal mosquito nets shall conform to the physical characteristics sp ecified in Table 1 when 
tested in accordance with the methods specified therein.  
Table 1 — Physical  characteristics for Long lasting insecticidal mosquito nets  
Parameter  Specification  
Test method   
Polypropylen e  
Polyester  Polyethylene  
Fibre  100% Polypropylene   
100 % polyester  100 % polyethylene  ISO 1833 -1,2,5,11,16,24, 
25 
ISO 11827  
Liner density 
(Denier), min.  100 ISO 2060  
Filaments  Mono/Multi -filament  Multi -filament  Mono/multi -filament   
Mesh count, 
holes/cm2,  20 – 25 20 – 25 
≥ 8  ISO 139, ISO 16663 -1 
 
Weight, g/m2,  ≥30 ≥36 40±10 ISO 3801  
Bursting strength 
at 7.3 cm2, Kpa, 
min 450 350  250 ISO 13938 -1 or ISO 
13938 -2 
Dimensional 
stability, max.   
Threshold of 5 %  ISO 5077  
ISO 6330  
ISO 3759  
Colour fastness 
to: 
 Light  
 Washing  4 or better  
4 or better  
  
ISO 105 -B01, B02  
EAS 237  
Seam   
Sewn using 100% polyester thread  
  
 
4.1.2 Active ingredient   
For mono -treated nets, the active ingredien t shall comply with the requirements of Table 2 when tested in 
accordance with the methods sp ecified therein.   
4 © EAC 2016  – All rights reserved  
 Table 2 ― Specification for  active ingredient for mono -treated nets 
SL NO  Ingredient*  Specification,  
g/kg 
 Test Method  
 
i Deltamethrin  1.05 – 2.8 
 
 A 
ii Permethrin  17 – 23 
 B 
iii Alpha –
cypermethrin  3.75 - 8.4 
 C 
* In the event that an active ingredient ot her than those already mentioned above is used, it shall be as  
recommended by WHO  (http://www.who.int/whopes/quality /) or any other internationally recognized body  
and their affiliated entities published specifications for public health pesticides for treated mosquito nets  
 
4.2 Combination nets  
4.2.1  Combination nets with single fibre construction shall comply with the requirements of Table 1 
and the active ingredient requirement shall be as follows:  
 Perm ethrin as 20 g/kg ± 25 %; and  
 Piperonyl butoxide (PBO) as 10 g/kg ± 25 %.  
 
4.2.2  Combination nets constructed with more than one fibre shall comply with the requirements of 
Table 3.  
Table 3 — Specification for combination nets  
Parameter  
 Requirement  Test method  
Roof  Sides  
Fibre composition  Polyethylene  Polyester  ISO 1833 -
1,2,5,11,16,24,25  
ISO 11827  
Linear density 
(Denier), min.  100 75 with strengthened 70 cm lower 
border or 100 without border  ISO 2060  
Mesh count, 
holes/cm²  20 – 25 20 – 25 ISO 139, I SO 
16663 -1 
Weight, g/m²  40 ± 5  35 ± 5  ISO 3801  
Bursting strength, 
kPa, min.  400 250 for 75 Denier and 350 for 100 
Denier  ISO 13938 -1 
Shrinkage/expansion 
(%) max.  5 5 ISO 5077  
ISO 6330  
Colour fastness to:  
 Light   
4 or better   
ISO 105  B01, 
B02  
© EAC 2016  – All rights reserved  5 
  Washing  4 or better  EAS 237  
Active 
ingredient *, g/kg  
 PBO:   4 ± 25 %.  
 Deltamethrin:  2.8 ± 25 %.  Annex D  
Annex A  
* As per WHO  (http://www.who.int/whopes/quality /) or any other internationally recognized body  and their affiliated entities 
published specifications for public health pesticides for treated mosquito nets  
 
4.3 Shapes, s izes and dimensions  
4.3.1  Shape  
The mosquito net shall be rectangular or conical in shape unless otherwise agreed between the purchase r 
and the supplier.  
4.3.2  Sizes and dimensions  
The nets shall be supplied in  sizes and dimensions  as specified in Table 4 and Table 5  for rectangular and 
conical nets respectively  or in other sizes, as the purchaser may require.  
Table 4 — Sizes and dimensi ons for r ectangular net  
No Net size  Width, min.,  
cm Length, min.,  
cm  Height, min.,  
cm  
1 X-small  70 120 150 
2 Small  100 180 170 
3 Medium  130 180 170 
4 Large  160 180 170 
5 X- Large  190 180 170 
 Test method  Annex E  
 
Table 5 — Sizes and dimensions fo r conical nets  
No. Net size  Height, min.,  
cm Circumference , min.,  
cm Top r ing diameter, min.,  
cm 
1 Dome shaped cover net  50 230 - 
2 X small  120 300 40 
3 Single fitted conical  180 850 56 
4 Double fitted conical  220 1050  56 
5 Extra double fitted  250 1250 65 
 Test method  Annex E  
  
6 © EAC 2016  – All rights reserved  
 .4.4 Manufacture and workmanship  
4.4.1  Construction   
4.4.1.1  Reinforcement at Bottom:  
The bottom edge of the w alls shall be stitched and reinforced.  The hem shall be firm and capable of 
withstanding the normal conditions of use . 
NOTE  A sheeting border is sometimes required to improve the lifespan of nets.  
4.4.1.2  Seams and Stitching  
When visually examined , the seams  shall be  of even tension throughout and loose ends securely fastened off. 
The net seams shall be made with lock st itch and  the number of stitches per decimetre shall be 30 to 38. The 
stitching shall be made by using spun polyester sewing thread of matching shade . 
4.4.1.3 Knit type  
The net shall be in any one of the warp knitted constructions for example raschel and tr icot as specified in ISO 
8388  
4.4.2  Net attachments or tying tapes  
4.4.2 .1 Rectangular nets shall be equipped with non -rusting metal rings or fabric loops.  
4.4.2 .2 Each ring/loop shall have a corresponding string for suspensions.  
4.4.2 .3 Conical nets sh all be equipped with a loop/non -rusting ring with sufficient strength.  
4.4.3 Top support ring  
Conical nets shall have a top support ring made of non -rusting metal and which has sufficient strength to 
withdraw the net when hanged at the required position.  
4.4.4  Defects  
The mosquito nets shall be free from defective holes (holes having diameter more than the normal hole size of 
the netting), stitching defects, stains and observable defects.  
5 Packing and labelling  
5.1 Packing  
For bulk packaging, the material  shall be leakproof, sufficiently large to wrap and strap completely the 
mosquito net bundles.  
For individual nets, the requirements for packaging materials shall comply with the respective Partner States 
relevant legislation . 
5.2 Labelling  
5.2.1  Outside packa ging  
The following information shall be legibly and indelibly marked on the outside packaging of  individual  nets  
© EAC 2016  – All rights reserved  7 
 a) type of netting fibre;  
b) net size and dimensions in centimetres (height, width and length for rectangular nets or diameter and 
height for conical  nets;  
c) country of origin;  
d) colour;  
e) name and physical address of the manufacturer and/or importer/distributor;  
f) lot or batch number;  
g) name and amount (in the net in grams per kilogram) of  insecticide incorporated  in the net ; 
h) care instructions in accordance wit h ISO 3758  
5.2.2  Tag 
The following information shall be legibly and indelibly marked on a permanent tag  attached to individual  nets 
a) brand name or registered  trademark;  
b) type of netting fibre ; 
c) net size and dimensions in centimetres (height, width and l ength  for rectangular nets or diameter and 
height for conical nets ; 
d) country of origin;  
e) name of the manufacturer and/or importer/distributor;  
f) lot or batch number;  
g) name and amount (in the net in grams per kilogram) of insecticide incorporated in the net;  
h) the effi cacy of the chemical indicated in terms of the number of washes  and; 
i) care instructions in accordan ce with ISO 3758  
7 Sampling  
7.1 Lot  
In any consignment all the pieces of mosquito nets delivered to a consignee against the same dispatch note 
shall consti tute a lot  
7.2 Scale of sampling  and testing  
The number of pieces to be selected from a lot shall be in accordance with table 6. Samples shall be tested 
from each lot for ascertaining conformity to the requirements of this East African Standard.  
 
  
8 © EAC 2016  – All rights reserved  
 Table 6 — Sampling plan  
Number of pieces in a lot  Number of pieces to be sampled  
Up to 8  2 
9 to 15  3 
16 to 25  4 
26 to 50  5 
51 and above  7 
  
© EAC 2016  – All rights reserved  9 
 Annex  A 
(normative)  
 
Determination of Deltamethrin content in long lasting insecticide treated 
mosquito nets by High Pe rformance Liquid Chromatography  
A.1 Sampling  
A sample is defined as one finished bed net taken randomly from a batch of bed net.  Sub -sample by cutting 
18 pieces of size 100 cm2 randomly from the whole net.  Cut 18 pieces into half, one portion is used fo r 
Deltamethrin content analysis and the other is used for washing test if required.  
The portion used for Deltamethrin content analysis is cut into pieces of less than 2 cm x 2 cm each.  Mix well. 
The sample shall be separately packed in aluminium foil and kept out of direct sunlight at room temperature or 
lower.  
A.2 Identification tests  
Use the HPLC method below.  The retention time of Deltamethrin in the sample solution should not deviate by 
more than 15 s from that of the calibration solution if column ov en is available.  
A.3 Active ingredient  
A.3.1  Outline of method  
The sample is extracted in a mixture of iso -octane and 1,4 -dioxane.  
The Deltamethrin content is determined by normal phase high performance liquid chromatography using 
dipropyl phthalate as int ernal standard and detection at 236 nm.  
A.3.2  Scope  
This method is used for Deltamethrin determination in the net sample, before and after washing.  
A.3.3  Reagents  
A.3.3.1  Iso octane , HPLC grade  
A.3.3.2  1,4 Dioxan , HPLC grade.  Add 0.15 % (v/v) water befor e use.  
A.3.3.3  Deltamethrin , neat standard  
A.3.3.4  Dipropyl phthalate   
A.3.3.5  Water, HPLC grade or high   
A.3.3.6  Extraction solvent (ES) : iso octane + 1,4 dioxane = 80 + 20  
A.3.3.7  Mobile Phase (MP) :iso octane + 1,4 dioxane = 95 + 5   
10 © EAC 2016  – All rights reserved  
 A.3.3.8  Internal stan dard solution  (IS), 0.5 mg/mL of dipropyl  phthalate in extraction solvent  
A.3.3.9  Deltamethrin standard solution,  0.6 mg/mL (DS)  
Weight 0.03 g(to the nearest of 0.01 mg) of Deltamethrin neat standard, quantitatively transfer to 50 -mL 
volumetric  flask, di ssolve completely with extraction  solvent , keep regulated by water bath at 20 °C, fill up to 
mark with extraction solvent.  
A.3.4  Apparatus  
A.3.4.1  Shaker  
A.3.4.2  Ultrasonic bath  
A.3.4.3  HPLC , equipment with pump, auto -injector, column oven (optional) and  UV detector, Guard              
Column (Supelguard Si). Analytical Column Supelco Si 5 µm, 150 x 4.6 or Lichrosorb Si60, 5 µm, 150 x 4.6  
A.4 Procedure  
A.4.1  Operating conditions  
A.4.1.1  Mobile Phase: iso octan + 1,4 dioxane = 95 + 5  
A.4.1.2  Flow rate 1.3m L/min, isocratic  
A.4.1.3  Guard Column Superguard Si  
A.4.1.4  Analytical Column Licherosorb Si 60, 5 µm, 150 x 4.6 40 °C if column oven is available, or room 
temperature  
A.4.1.5  Inject volume 5 µL  
A.4.1.6  Wavelength 236 nm  
A.4.1.7  Run time 6 min - 8 min  
A.4.2 Preparation of calibration curve  
A.4.2.1  Into a series of clean 20 mL PTFE liner screw cap vials, add accordingly as table below.  Filter 
through 0.45 µm syringe filter before use.  
Code  IS, 
mL DS, 
mL ES, 
mL Delta,  
mg Total volume,  
mL 
C1 1 0.5 13.5  0.30 15 ml  
C2 1 0.7 13.2 ml  0.42 15 ml  
C3 1 0.9 12.8 ml  0.54 15 ml  
C4 1 1.1 12.4 ml  0.66 15 ml  
C5 1 1.3 12.1 ml  0.78 15 ml  
 
A.4.2.2  All standards should be kept in the refrigerator if not in use in well -tightened paraffin film sealed 
cap.  
© EAC 2016  – All rights reserved  11 
 A.4.3  Calibratio n 
Daily calibrate HPLC system with full series of 05 standards, beginning with the lowest level standard.  The 
correlation coefficient should be less than 0.99 over this range.  
A.4.4  Preparation of sample  
Weigh (to the nearest 0.1 mg) into an Erlenmeyer or  a screw cap neutral glass bottle (50 mL) sufficient 
sample to contain about 0.5 mg of Deltamethrin.  For 75D, 100D and 150D netting sample, suitable weight ( w 
g) is 0.3 g, 0.4 g and 0.6 g respectively.  Add by pipette 1.0 mL internal standard solution.  A dd 14 mL extract 
solvent.  Replace the cap closely.  
Put the bottles into the ultrasonic bath, setting temperature 80 °C, running time 15 min.  Vigorously shake the 
bottle using the shaker in 30 min at room temperature, speed of shaking is at level of 150 - 200 beats per 
minute.  
Using a syringe membrane filter with pore size of 0.45 µm or finer, filter c.a 1 mL of extract solution into clean 
amber. The sample shall be injected within 24 h since extraction; for longer waiting time the vial should be 
kept in a  refrigerator.  
A.4.5  Determination  
Deltamethrin content (g/kg) = 
wa  
where  
a is the Deltamethrin reading from the analysis in milligrams; and  
w is the mass, in grams, of sample taken.  
NOTE  Conventional unit of active ingredient content (deltamethrin) for netting is milligrams per square metre.  The 
conversion from grams per kilogram (g/kg) to milligrams per square metre (mg/m2)   is made as follows:  
Deltamethrin content (mg/m2) = Deltamethrin content (g/kg) x D  
where  
D is the weight per square metre of typical polyester netting  
 75 Denier netting, D=30 g/m2 
 100 Denier netting, D=40 g/m2 
 150 Denier netting, D=60g/m2 
A.4.6  Method validation summary  
A.4.6.1  Precision  
Analyze 05 replicates RSD is 1.8 %.  
A.4.6.2  Accuracy  
Recovery of 04 Laborato ry Synthetic samples is in the range of 97 % to 101 %.  
Averaged at 99.3 %   
12 © EAC 2016  – All rights reserved  
 A.4.6.3  Linearity  
Over the range of Deltamethrin from 0.30 mg to 0.78 mg, the correlation coefficient R2 is observed not less 
than 0.995.  
Determination of release /Retention Index  
 
Figure 1 ― Chromatogram of calibration solution  
 
Figure 2 ― Chromatogram of sample   
© EAC 2016  – All rights reserved  13 
 Annex B  
(normative ) 
 
Determination of Permethrin content in long lasting insecticide treated 
mosquito nets  
B.1 Sample preparation  
B.1.1  General  
Take at least 100 g.  
B.1.2  Identity tests  
B.1.2.1  GLC, equipped with a split/splitless and a flame ionization detector. Capillary column fused silica, 
30 m x 0.25 (i.d) mm, film thickness:0.25 µm, coated with cross linked dimethyl (DB -1 or equivalent) and 
electric integrator or dat a system  
B.1.2.2  Infrared. Extract the sample with suitable solvent.  Filter and evaporate the solvent.  Proceed as 
for 331/TC/m/2.2  
B.1.2.3  Permethrin. The content of permethrin in test samples are determined by capillary GC using 
flame ionization detecti on and triphenyl phosphate as internal standard, and trans -isomer ratio is calculated 
from the chromatogram obtained  
B.2 Reagents  
B.2.1  Heptane analytical grade  
B.2.2  Internal standard solution .  Dissolve triphenyl  phosphate (1.0 g) in heptane (150 mL).  Ensure that 
a sufficient quantity of this solution is prepared for all samples and calibration standards to be analysed.  
B.2.3  Calibration solution .  Homogenise the permethrin working standard.  When the permethrin working  
standard is waxy solid or partl y waxy solid homogenize it by warming it to melting and stirring.  Prepare 
calibration solutions in duplicate.  Weigh (to the nearest 0.1 mg) 72 mg - 88 mg of permethrin working 
standards into a vial or stoppered flask (200 mL).  Add by pipette internal st andard solution (10 mL) and 
dissolve completely.  Add by measuring cylinder heptanes (90 mL) and mix well (solutions C A and C B) 
B.3 Procedure  
B.3.1  Preparation of sample solution  
Clean scissors with acetone before use.  Cut the sample with the scissors int o 5 mm -10 mm square.  Prepare 
sample solutions in duplicate for each sample.  Weigh (to the nearest 0.1 mg) sufficient sample to contain 36 
mg - 44 mg (w mg) of permethrin into a vial or stoppered flask (100 mL).  Add by pipette internal standard 
solution  (5 mL) and by measuring cylinder heptane (45 mL).  Place the vial or stoppered flask in a water 
bath(85 ºC – 90 ºC) for 45 min.  Shake the vial or stoppered flask once or twice during extraction.  Filter a 
portion of each sample solution through a filter paper prior to analysis (Solutions S A and S B)  
14 © EAC 2016  – All rights reserved  
 B.3.2  Calculation of permethrin content   
B.3.2.1  Calculate the mean value of each pair of response factors bracketing the two injections of a 
sample and use this value for calculating the permethrin contents o f the bracketed sample injections.  
2xxx
sr
i
HPslf
 
Content of permethrin, g/kg 
wlHf
xx
qw  
where  
fi is the individual response factor,  
f is the mean response factor,  
Hs is the total peak area of permethrin (cis -permethrin + trans -permet hrin) in the calibration solution,  
Hw is the total peak area of permethrin (cis -permethrin + trans -permethrin) in the sample solution,  
Ir is the peak area of the internal standard in the calibration solution,  
Iq is the peak area of the internal standard i n the sample solution,  
s is the mass, in milligrams, of permethrin working standard in the calibration solution,  
w is the mass, in milligrams, of sample taken, and  
P is the purity, in grams per kilograms, of permethrin working standard.  
B.3.2.2  To determin e precision,  
Repeatability, r =  1.6 g/kg at 20.3 g/kg active ingredient content  
      1.3 g/kg at 20.0 g/kg active ingredient content  
      0.9 g/kg at 18.7 g/kg active ingredient content  
Reproducibility, R = 1.9 g/kg at 20.3 g/kg active ingredient conten t 
      1.5 g/kg at 20.0 g/kg active ingredient content  
      1.5 g/kg at 18.7 g/kg active ingredient content  
B.4 Determination of surface concentration and release index  
B.4.1  Reagents  
To prepare the internal standard solution for calibration solution, di ssolve triphenyl phosphate (0.1 g) in 
acetone (200 mL) to prepare a stock solution.  Transfer by pipette the stock solution (5 mL) to a volumetric 
flask (50 mL).  Make up to volume with acetone and mix well.  Ensure that a sufficient quantity of this solut ion 
is prepared for all calibration standard to be analysed.   
© EAC 2016  – All rights reserved  15 
 To prepare the calibration solution, homogenise the permethrin working standard .  When the permethrin 
working standard is always solid or partly solid homogenise it by warming it to melting and b y stirring.  Prepare 
calibration solutions in duplicate.  Weigh (to the nearest 0.1 mg) 90 mg - 110 mg (s mg) of permethrin working 
standard into a volumetric flask (100 mL) and make up to volume with acetone and mix well.  Transfer by 
pipette this solutio n (1 mL to a volumetric flask (20 mL), make up to volume with acetone and mix well.  
Transfer by pipette this solution (5 mL) to a vial (20 mL), add by pipette internal standard solution for 
calibration solution (5 mL) and mix well (Solution C A and C B). 
B.4.2 Apparatus as for 331/TC/m/3 except:  
B.4.2.1  Constant temperature oven  capable of controlling temperature with the range of ±2 °C is 
recommended.  
B.4.2.2  Rotary evaporator  
B.4.3  Procedure as for 331/TC/m/3 except:  
B.4.3.1  Gas chromatographic conditions (typical)  
B.4.3.2  Injection system  
B.4.3.3  Slit flow approximately 10mL/min  
B.4.4  Linearity check  
Check the linearity of the detector response by injecting 1 µL of solution s with permethrin concentrations 0.1, 
1 and 2.5 times that of the calibration solut ion before conducting analysis.  
B.4.5  System equilibration  
Prepare two calibration solutions.  Inject 1 µL portions of the first one until the response factors obtained for 
two consecutive injections differ by less than 2.0 %.  Then inject a 1 -µL portion of the second solution.  The 
response factor for this solution should not deviate by more than 2.0 % from that for the first calibration 
solution, otherwise prepare new calibration solutions.  
B.4.6  Preparation of sample solution  
Clean scissors and tweezers  with acetone before use.  Prepare sample solutions in tripricate for each sample 
(see Note 1) Cut ca .5 cm x 5 cm net samples with the scissors.  Weigh accurately, to the nearest 0.1 mg, of 
each sample (w mg). Transfer it with the tweezers into a vial (20  mL).  Add by pipette internal standard 
solution for sample solution (10 mL).  Cap the vial and shake the solution by hand for 1 min (see Note 2).  
Take out ht netting with the tweezers and discard the solution.  
Let the netting dry at room temperature for ca. 10 min. Transfer it into a vial (20 mL) with the tweezers.  Cap 
the vial and place it in a temperature -controlled oven set at 70 OC.  Heat the sample for 2 h (see Note 3). After 
heating, remove the vial from the oven and let it equilibrate to room temp erature.  Add by pipette internal 
standard solution for sample solution (10 mL) into the vial.  Cap the vial tweezers.  Let the netting dry at room 
temperature for ca. 10 min. Transfer the sample solution from the vial into the same round -bottom flask.  
Evaporate the solution in vacuo to dryness.  Add by pipette acetone (2 mL) into the flask to dissolve the 
residue (solutions for “surface concentration at pot -wash 1”, S A1,SBI and S C1).    
Transfer the dried netting into a vial (20 mL) with the tweezers.  Re peat heating, internal standard solution 
adding, evaporation and dissolving procedures as above (solutions for surface concentration at post -wash 2”, 
SA2, SB2 and S C2). Let the netting dry at room temperature for ca. 10 min.  Transfer the dried netting in to a vial 
(20 mL) with the tweezers.  Repeat heating, internal standard solution adding, evaporation and dissolving 
procedures as above.  (Solutions for surface concentration at post -wash 3”, S A3,SB3, and  S C3)  
16 © EAC 2016  – All rights reserved  
 NOTE 1  Analytical error is larger than averag e content determinations. Triplicate determinations, therefore, are 
recommended.  
NOTE 2  The shaking speed is about 30 times per 10 s  
NOTE 3  Put vials in a covered cardboard box while heating so that the vials are not exposed to direct streams of warm   
air. 
B.4.7  Determination  
Inject in duplicate 1 µL portions of each sample solution bracketing them by injections if the calibration 
solutions as follows; calibration solution  CA, sample solution S A1, sample solution S A1, calibration solution CB, 
sample solu tion S B1, sample solution S B1, calibration solution CA and so on measure the relevant peak areas.  
B.4.8  Calculation of surface concentration  
Calculate the mean value of each pair of response factors bracketing the two injections of a sample and use 
this v alue for calculating the surface concentration of the bracketed sample injections.  
sr
ixx
HPslf
 
Surface concentration, µg/g 
2xxx
qw
wlHf  
where  
fi is the individual response factor,  
f is the mean response factor,  
Hs is the total peak a rea of permethrin (ci s-permethrin + trans -permethrin ) in the calibration solution,  
Hw is the total peak area of permethrin (cis -permethrin + trans -permethrin) in the sample solution,  
Ir is the peak area of the internal standard in the calibration solution,  
Iq is the peak area of the internal standard in the sample solution,  
s is the mass of permethrin working standard taken,  
w is the mass of sample taken, and  
P is the purity of permenthrin working standard.  
B.4.9  Calculation of release index  
Calculate the mean value of the two injections of sample solutions SA3, SB3, and SC3 by the equations 
described in B.9.1 , and the release inde x for each piece of the netting.  
Release index =
BC  
Where  
B is the mean value of surface concentration at po st-wash 2 (µg/g)   
© EAC 2016  – All rights reserved  17 
 C is the mean value of surface concentration at post -wash 3 (µg/g)  
 
Figure 1 ― Infrared spectrum of permethrin  
 
Figure 2 ― Example of gas chromatogram of permethrin TC   
18 © EAC 2016  – All rights reserved  
 
 
Figure 3 ― Example of gas chromatogram of permethrin LN  
 
  
© EAC 2016  – All rights reserved  19 
 Annex C  
(normative)  
 
Determination of Alphacypermethrin content in long lasting insecticide 
treated mosquito nets  
C.1 Sampling  
Take net specimens.  
C.2 Identity test  
GLC capable of operating over a range 100 ºC - 300 ºC, fitted with a flame ionization detector  
C.3 Alphacypermethrin  
Alphacypermethrin 454/TC/(M)3 is dissolved in tetrahydrofuran and determined by capillary gas 
chromatography in split injection mode using flame ionization and internal standardization.  
C.4 Reagents  
C.4.1  Tetrahydrofuran  
C.4.2  Aphacyperme thrin standard  of known purity, Di(2 -ethylhexyl)phthalate(dioctyl phthalate, DOP), 
internal standard,purity atleast 980 g/kg and giving no peaks with similar retention times to alphcypermethrin  
C.4.3  Citric acid 5% solution,  dissolve citric acid (25 g) in water (500 mL)  
C.4.4  Internal standard solution,  dissolve dioctyl phthalate (5.0 g) intetrahydrofuran (500 mL). Ensure 
sufficient quantity of this solution is prepared for all samples and calibration solutions to be analysed.  
C.5 Calibration solutions  
C.5.1 Preparation of calibration solutions  
Weigh 50 mg alpha cypermethrin (to the nearest 0.1 mg) in a volumetric flask (25ml). Fill to the mark with 
THF. Place the flask in an ultrasonic bath for 10 min. After temperature equilibrium pipette 1.50 mL, 4.50 mL 
of this solution into three volumetric flaks (50 mL). Add 0.5 mL of internal standard solution (dioctyl phthalate, 
1 % in acetone) and fill up each to the mark with THF.  
These solutions are used as calibration solutions A (C A), B (C B) and C (C C). Transfer 200 µL out of each flask 
into separate GC vials. Add one drop of citric acid in each case and seal the vials. Place the vials into the 
sample tray (cooled down to 15 ºC) of the GC apparatus.  
NOTE  Citric acid is added to stop epimerization of alphacypermeth rin in solution.   
20 © EAC 2016  – All rights reserved  
 C.5.2  Description of calibration solutions  
The calibration solutions are described as follows:  
 CA: concentration of approximately 3.0 mg alphacypermethrin in 50 mL THF;  
 CB: concentration of approximately 6.0 mg alphacypermethrin in 50 mL THF; and  
 CC: concentration of approximately 9.0 mg alphacypermethrin in 50 mL THF.  
C.5.3  Apparatus  
C.5.3.1  Gas chromatograph  with flame ionization detector (for example, HP6890 Plus)  
C.5.3.2  Automatic sample injector (for example, HP series 7683) equipped with a sample which is 
cooled down to 15 ºC  
C.5.3.1  Capillary column fused silica (for example, DB -1) 30mx 0.32 mm, film thickness of 0.25 µm  
C.5.3.2  Electronic data evaluation system  (for example, HP ChemStation)  
C.5.3.3  Ultrasonic bath  
C.5.3.4  Electronic  balance  
C.5.3.5  Laboratory glassware  
C.6 Procedure  
C.6.1  Operating conditions  
As per alphacypermethrin 454/TC/(M)3  
C.6.2  Preparation of the samples  
C.6.2.1  Determination via the water/detergent extraction process  
C.6.2.1.1  First step: Quantification of t he adherent contents of alphacypermethrin on surface fibres  
a) Procedure done by manufacturer  
Place 2 g impregnated net in a beaker (1L).Add soap (commercially available bar soap or as flakes, 
2g/L) and water (500 mL). The washing is done for 10 min at 30 ºC on a shaker with 155 
movements/min. Directly after the washing, the wash liquor is acidified with 10 mL/L acetic acid 30% 
in order to prevent hydrolysis of the extracted alphacypermethrin (note:there is no difference in 
hydrolysis in neutral water compared  to wash liquor after 10 min. at 30 ºC). Transfer 150 mL of the 
washing liquid into a separation funnel (500 mL). The extraction procedure is done twice with 100ml 
ethyl acetate each by shaking twice for 30 s. Both portions of ethyl acetate are combined to gether in a 
flask (250 mL). Ethyl acetate is evaporated in a rotary evaporator. The flask is stoppered and sent to 
the analytical laboratory.  
b) Procedure done by analytical laboratory  
Fill up the flask with THF (50 mL). Add 0.5 mL of internal standard soluti on (dioctyl phthalate, 1 % in 
acetone). Transfer 200 µL of sample out of the flask into a separate GC vial. Add one drop of citric 
acid into the vial.   
© EAC 2016  – All rights reserved  21 
 C.6.2.1.2  Second step: Quantification of the total contents of alphacypermethrin  
Weigh (to the nearest 0. 1 mg) 1 g of the impregnated net into a volumetric flask (100 mL) and add THF (50 
mL). Place this flask in a refluxing apparatus. Heat up the flask in the apparatus and reflux at approximately 
90 ºC (oil bath temperature). Sampling will be done after 5 min . refluxing. Add 0.5 mL of internal standard 
solution (dioctyl phthalate, 1 % in acetone). Transfer 200 µL of the sample into separate GC vial. Add one 
drop of citric acid into the vial.  
C.6.2.2  Determination via the n -hexane extraction process  
C.6.2.2.1  First step: Quantification of the adherent contents of alphacypermethrin on the surface of 
the fibers  
Weigh (to the nearest adherent drops of n -hexane)  out of the flask into another volumetric flask (100 mL) and 
add THF (50 mL). Place this flask in a reflux ing apparatus. Heat up the flask in the apparatus and reflux at 
approximately 90 ºC. Sampling will be done after 5 min refluxing. Add 0.5 mL of internal standard solution 
(dioctyl phthalate, 1 % in acetone). Transfer 200 µL of the sample into a separate GC  vial. Add one drop of 
citric acid into the vial.  
C.6.2.2.2  Second step: Quantification of the total contents of alpha -cypermethrin  
Transfer the net  (without adherent drops of n -hexane) out of the flask in to another volumetric flask (100 mL) 
and add THF ( 50 mL). Place this flask in a refluxing apparatus. Heat up the flask in the apparatus and reflux at 
approximately 90 ºC. Sampling will be done after 5 min refluxing. Add 0.5 mL of internal standard solution 
(dioctyl phthalate, 1 % in acetone Transfer 200 µ L of the same into a separate GC vial. Add one drop of citric 
acid into the vial.  
C.6.2.3 System calibration  
As for alphacypermethrin 454/TC/(M3)  
C.6.2.4  Determination  
Each calibration solution C i and each sample solution S J is injected twice. The followin g sequence is advised:  
CA , CA,, CB, CB,CC, CC, SA, SA,SB, SB,SC,SC,… 
C.6.2.5  Calculation  
As for alphacypermethrin 454/TC/(M)3 and see test of linearity  
Concentration 
wlHf
xx
qw  
Where  
f is the response factor  
Hw  is the total peak area of alph acypermethrin (cis +ll) in the sample solution  
Lq  is the peak area of internal standard in the sample solution  
w  is the mass of sample taken  
C.6.2.6  Surface concentration and Release index  
a) Determination   
22 © EAC 2016  – All rights reserved  
 The determination of alphacypermethrin content is d one via the n -hexane extraction process from fibres.  
Each calibration solution Cj and each sample solution Sj ai are injected twice. The following sequence is 
advised: C A, CA,CB,CB,CB,CC,CC,SA1,SA1,SA2,SA2,SA3,SA3,SB1,SB1,... 
 SA is the first rinse; S A mean  value of S A1, SA2,SA3 
 SB  is the second rinse; S B mean value of S B1,SB2,SB3 
 Sc  is the third rinse; S C mean value of S C1, SC2,SC3 
where 1,2,3 are net samples  
b) Calculation of the release index  
Calculate the mean value of sample solutions S C and S B by the eq uations described in 6.2.5 and the release 
index for each piece of netting.  
Release index = 
)S(S1B C/  
Where  
SB refers to second rinse; S B mean SB1,SB2,SB3 
SC refers to third rinse; S C mean value of SC1, SC2,SC3 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
© EAC 2016  – All rights reserved  23 
 Annex D  
(normat ive) 
 
Determination of Piperonyl butoxide in polyethylene matrix in long 
lasting insecticide treated mosquito nets  by G as Chromatography  
D.1 Scope   
The method is suitable for the determination of piperonyl butoxide in polyethylene matrix.  
D.2 Outline of me thod  
The sample is extracted by refluxing with xylene. The piperonyl butoxide content is determined by capillary 
gas chromatography using flame ionisation detection and internal standard.  
D.3 Reagents  
a) Xylene  
b) Piperonyl butoxide standard of known purity. St ore below 0°C.  
c) Octadecane internal standard: Internal standard solution. Weigh (to the nearest 0.1 mg) into a 
volumetric flask (50 ml) octadecane (0.4 g). Fill to the mark with xylene and mix well.  
d) Calibration solutions: Allow piperonyl butoxide to equili brate to ambient temperature. Then weigh (to 
the nearest 0.1 mg) into a volumetric flask (50 ml) 0.25 g. Fill to the mark with xylene and mix well. To 
pipette 0.50 ml, 1.50 ml, 2.00 ml, 3.00 ml and 4.00 ml of this solution into 5 volumetric flasks (25 ml).  
Add 2 ml of internal standard solution and fill up each to the mark with xylene and mix well.  
i. Five solutions are used as calibration solutions A  (CA), B  (CB), C  (CC), D  (CD), E  (CE).  Transfer 
200 m l out of each flask into separate GC vials. Place the vial  into the sample tray of GC 
apparatus.  
ii. Description of the calibration solutions:  
 CA: concentration of approximately 2.5 mg piperonyl butoxide in 25 ml xylene  
 CB: concentration of approximately 7.5 mg piperonyl butoxide in 25 ml xylene  
 CC: concentration of approximately 10.0 mg piperonyl butoxide in 25 ml xylene  
 CD: concentration of approximately 15.0 mg piperonyl butoxide in 25 ml xylene  
 CE: concentration of approximately 20.0 mg piperonyl butoxide in 25 ml xylene  
D.4 Apparatus  
D.4.1  Gas chromatograph capab le of operating over the range 180 to 250°C fitted with a flame ionisation 
detector, a split injector, and an auto sampler.   
24 © EAC 2016  – All rights reserved  
 D.4.2  Capillary column fused silica, 30 m x 0.32 mm (i.d.) with 100% methyl polysiloxane, cross -linked, 
surface bonded stationary p hase  and 0.25 µm film thickness (Durabond -1 or equivalent) .  
D.4.3  Electronic integrator or data system  
D.5 Operating Procedure  
D.5.1  Operating conditions (typical):  
a) Column: Fused silica, 30 m x 0.32 mm (i.d.) with 100% methyl polysiloxane, cross -linked, s urface 
bonded stationary phase and 0.25 µm film thickness (Durabond -1 or equivalent)  
b) Injection system: Injector  Split injection  
c) Injector temperature  250°C  
d) Sprit ratio  20:1 
e) Purge flow  1 ml/min  
f) Injection volume  1 µl 
g) Detector system: Type; Flame ionisation  
h) Temperature  300°C  
i) Oven temperatures: Initial  180°C  
j) Program;  
 180°C hold for 11 min  
 200°C at 10°C/min, hold for 8 min  
 210°C at 10°C/min, hold for 18 min  
 245°C at 30°C/min, hold for 4 min  
 Total run time  45 min  
k) Gas flow rates  
 Helium (carrier)  linear velocity: 39  cm/min at 180°C  
 Helium (make up)  30 ml/min  
 Hydrogen  40 ml/min  
 Air 400 ml/min  
l) Total flow  35 ml/min  
m) Retention time;  
 octadecane: about 6 min   
© EAC 2016  – All rights reserved  25 
  piperonyl butoxide: about 23 min  
D.5.2  Preparation of sample.  
Cut the sample with scissors into 1 – 2 cm squares and  thoroughly mixed. Weigh (to the nearest 0.1 mg) 
sufficient sample to contain 12.5 mg of piperonyl butoxide into a 250 ml reflux flask. Add 23 ml xylene and 2 
ml internal standard solution. Reflux the sample about 30 minutes. Cool down the sample to room 
temperature. Filt er the solution through a 0.45 µm Teflon filter membrane. Transfer into a separate GC vial.  
D.5.3  System equilibration.  
Inject into the gas chromatograph a 1 µl portion of the sample solution to condition the column and to check 
for the a ppropriate flow rates and integration events.  
D.5.4  Determination.  
tions in the 
following sequence; CA, CA, CB, CB, CC, CC, CD, CD, CE, CE, S1, S1, S2, S2, etc . 
D.6 Calculation.  
Concentration = R/w (g/kg)  
Where:  
R = Piperonyl butoxide reading from the analysis in mg  
w = mass of sample taken in g  
 
 
 
 
 
 
 
 
 
 
 
  
26 © EAC 2016  – All rights reserved  
 Annex  E 
(normative)  
 
Measurement of mosquito net  dimensions  
D.1 Rectangular nets : Length, width and heigh t 
D.1.1  Apparatus  
a) Flat table  
b) Measuring tape or steel rule  
D.1.2  Conditioning  
Condition the ne t samples in accordance with ISO 139.  
D.1.3  Procedure  
Lay the conditioned net sample on a flat table (D.1.1.2), and take measurements of height, width and 
diameter . 
D.1.4  Calculation  
If more than one net sample is tested, take the average measurement for each dimension.  
D.1.5  Report  
Report the value of the net dimension as the average calculated in D.1.4 in centimetres.  
D.2 Circular nets : Top ring diameter, bottom c ircumference and conical height  
D.2.1 Apparatus  
a) Hook  supported at a vertical distance of at least more than the height of the net sample to be tested.  
b) Measuring tape or steel rule  
c) Twine, of measuring at least 10 m  
d) Felt pen marker  
D.2.2  Conditioning  
Conditi on the n et sample in accordance with ISO 139.   
© EAC 2016  – All rights reserved  27 
 D 2.3  Procedure  
D.2.3.1  Top ring diameter  
D.2.3.1.1  Procedure  
Place the top portion of the net  sample on a flat table (D.1.1.a ) and put the twine (D.2.1 c ) around the 
circumference of the top ring of the net sa mple, identifying the two ends with a mar ker (D 2.1 d  ) which 
represent the dimension of the top ri ng. Using a measuring tape (D.2.1 b ) determi ne the top ring 
circumference (s ) of the net as the distance between the two points marked on the twines.  Repeat the test on 
each of the other net sample s. 
D.2.3.1.2  Calculation  
Take the average of the individual measurements as the top circumference of the conical nets.  
D.2.3.1.3  Report  
Report the top ring circumference as the value(S) calculated in D.2.3.1.2 in cen timetres.  
D.2.3.2  Bottom circumference  
D.2.3.2.1  Procedure  
Lay the bottom part of the net on a flat table removing any curls and take the measurement (N) from one end 
of the flattened net to the other using a twine. Repeat the procedure for other ne t samples.  
D.2.3.2.2  Calculation  
Take the average of the measurements (N.) taken in D.2.3.2.1.  
Calculate the bottom circumference as N x 2.  
D.2.3.2.3  Report  
Report the value of bottom circumference of the net as the value (N x 2) calculated in D.2.3.2.2 in  centimetres.  
D.2.3.3  Conical net height  
D.2.3.3.1  Procedure  
Hang the net with the loop from a hook. Take measurements of height along all the vertical seams.  
D.2.3.3.2  Report  
Report the least measurement taken as the conical net height.  
  
28 © EAC 2016  – All rights reserved  
 Bibliography  
1] Roll Back Malaria - Specification for Netting materials  – WHO publication  
[2] IS 9886: 1981 Indian Standard Specifications for mosquito nets   
[3] WHO Interim specification 331/LN (July 2006)  
[4] WHO Interim Specification 333/LN (December 2009)  
[5] WHO in terim specification 454/LN/1(October 2009  
[ 
. DEAS 455: 2016    
 
© EAC 2016  – All rights reserved