ISO 22258:2020

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 22258
ISO/TC 249
Traditional Chinese medicine —
Secretariat: SAC
Determination of pesticide
Voting begins on:
2020­04­14 residues in natural products by gas
chromatography
Voting terminates on:
2020­06­09
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ISO/FDIS 22258:2020(E)
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©
NATIONAL REGULATIONS. ISO 2020

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ISO/FDIS 22258:2020(E)

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ISO/FDIS 22258:2020(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Sampling . 1
5 Determination of pesticide residues . 2
5.1 Reagents. 2
5.1.1 General. 2
5.1.2 Check for purity of reagents . 2
5.2 Apparatus . 2
5.3 Qualitative and quantitative analysis of pesticide residues . 2
5.4 Test . 3
6 Limits . 3
Annex A (informative) Determination of pesticide residues in natural products used in TCM
by GC . 4
Annex B (informative) Maximum limits of pesticide residue in natural products used in
TCM (based on the European Pharmacopoeia and US Pharmacopoeia) .7
Annex C (informative) Recommended limits of pesticide residues in dried fruit, vegetable
or herbal medicine from WHO and FDA/EPA .10
Bibliography .13
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ISO/FDIS 22258:2020(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
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ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
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iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 249, Traditional Chinese medicine.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
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ISO/FDIS 22258:2020(E)

Introduction
A pesticide is any substance or mixture of substances intended to prevent, destroy or control any
pest, unwanted species of plants or animals causing harm during, or otherwise interfering with, the
production, processing, storage, transport or marketing of uncontaminated products. At present, there
is no uniformly accepted international standard which defines maximum limits for pesticides in natural
products used in traditional Chinese medicine (TCM), resulting in disputes about what levels should be
considered acceptable.
This document was developed in response to worldwide demand for harmonization of the determination
of pesticide residues. This document is applicable to natural products used in TCM.
For reference, the method of determination of pesticide residues by gas chromatography (GC) is
provided in Annex A, the maximum limits of pesticide residues in natural products used in TCM are
provided in Annex B and the recommended limits of pesticide residues in dried fruit and vegetables,
which is similar to TCM materials or herbal medicine from the World Health Organization (WHO) and
Food and Drug Administration/Environmental Protection Agency (FDA/EPA), are given in Annex C.
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FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 22258:2020(E)
Traditional Chinese medicine — Determination
of pesticide residues in natural products by gas
chromatography
1 Scope
This document specifies the method of determination of pesticide residues in natural products used
in traditional Chinese medicine (TCM) by gas chromatography (GC), including Chinese materia medica
(whole medicinal materials) and decoction pieces derived from plants.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
pesticide
substance or mixture of substances intended for preventing, destroying, repelling or reducing any pest
or weeds
[SOURCE: ISO 27065:2017, 3.9, modified — Note 1 to entry removed.]
3.2
pesticide residue
pesticide, pesticide derivative or pesticide adjuvant that remains in or on a natural product
Note 1 to entry: Pesticide residues are expressed in mg/kg.
3.3
acceptable daily intake
ADI
estimate of the amount of a pesticide in natural products that can be safely consumed daily over a
lifetime without adverse health effects
Note 1 to entry: ADI is expressed in milligrams of the pesticide, as it appears in the natural products, per
kilograms of body mass per day (mg/kg/day).
4 Sampling
To reduce the effect of sampling in the determination of pesticide residues in natural products used in
TCM, ensure that the composition of the sample used is representative of the batch of natural products
used in TCM being examined. The sampling procedures may be used if they can be demonstrated to
produce representative batch samples.
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ISO/FDIS 22258:2020(E)

Samples shall be accompanied with complete information (e.g. name, source, specification of the
samples) to ensure traceability.
5 Determination of pesticide residues
5.1 Reagents
5.1.1 General
Use reagents of purity suitable for pesticide residue analysis. All reagents shall be of recognized
chromatographic or analytical purity. Avoid possible contamination of water, solvents, sorbents
inorganic salts or other reagents.
5.1.2 Check for purity of reagents
When using GC the purity of the reagents used shall be checked by running a blank determination. The
chromatogram obtained from the solvents shall have a baseline without noticeable peak that would
interfere or overlap with the peaks from the chromatogram of the targeted pesticide residue (see
ISO 4389:2000, Clause 4).
5.2 Apparatus
All equipment, especially glassware, shall be thoroughly cleaned to ensure that it is free from
pesticides. All glassware shall be soaked for a minimum of 16 h in a solution of phosphate­free
detergent, rinsed repeatedly with distilled water to remove the detergent residue, then washed with
acetone, followed by hexane or heptane. Do not use ordinary plastics, for example PVC stoppers, in
vessels for storing standard materials and solutions as they can cause contamination. Polypropylene
(PP), polytetrafluoroethylene (PTFE) or nylon tubing and glass or PTFE stoppers usually present the
lowest risk of contamination.
Common laboratory glassware or equipment such as beakers, round-bottomed flasks, watch glasses,
pipettes, filter papers, glass wool, glass rods and glass beads are not listed in method in detail.
5.3 Qualitative and quantitative analysis of pesticide residues
Validated analytical procedures that satisfy the following criteria shall be used:
1) The chosen method, especially the purification steps, is suitable for the combination pesticide
residue/substance to be examined, and not susceptible to interference from co-extractives.
2) Natural occurrence of some constituents is considered in the interpretation of results (e.g. disulfide
from cruciferaceae).
3) The concentration of test and reference solutions and the setting of the apparatus are such that
the responses used for quantification of the pesticide residues are within the dynamic range of the
detector. Test solutions containing pesticide residues at a level outside the dynamic range may be
diluted within the calibration range, provided that the concentration of the matrix in the solution is
adjusted in cases where the calibration solutions must be matrix-matched.
4) Between 70 % and 120 % of each pesticide is recovered; lower recoveries may be acceptable in
certain justified cases.
5) Repeatability of the method: relative standard deviation (RSD) is not greater than the values
indicated in Table 1.
6) Reproducibility of the method: RSD is not greater than the values indicated in Table 1.
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ISO/FDIS 22258:2020(E)

Table 1 — The request of the repeatability and reproducibility of the method for
determination of pesticide residues
Concentration range of the pesticide Repeatability (RSD) Reproducibility (RSD)
mg/kg % %
0,001 – 0,01 30 60
> 0,01 – 0,1 20 40
> 0,1 – 1 15 30
> 1 10 20
5.4 Test
For reference, the method of determination of pesticide residues by GC is provided in Annex A. In certain
cases it is possible to improve the method performance by variations in equipment used, extraction,
clean-up and chromatographic conditions. Such variations shall always be clearly documented and
demonstrated to give valid results.
6 Limits
Limits for pesticides are calculated using the following formula:
Limit (mg/kg) = Am/100B
where
A is the ADI, in mg/kg of body mass;
m is body mass, in kg (60 kg);
B is the daily dose of the article, in kg.
The competent authority may grant total or partial exemption from the test when the complete history
(nature and quantity of the pesticides used, date of each treatment during cultivation and after the
harvest) of the treatment of the batch is known and can be checked precisely according to good
agricultural and collection practice (GACP).
Maximum limits of pesticide residues in natural products used in TCM are provided in Annex B.
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ISO/FDIS 22258:2020(E)

Annex A
(informative)

Determination of pesticide residues in natural products used in
TCM by GC
A.1 Extraction
Use the following procedure for the analysis of samples of articles having a water content of less than
15 %. Samples having a higher water content may be dried, provided that the
...