🧪 Organophosphorus pesticides in water and wastewater — GC after dichloromethane extraction

Physicochemistry PN-EN 12918

Overview

WHAT THIS STANDARD DESCRIBES. The scope from the PKN catalogue card, in full: "Przedstawiono sposoby ekstrakcji i analizy chromatograficznej (GC) stosowane do oznaczania parationu, parationu metylowego i kilku innych związków fosforoorganicznych w wodzie do spożycia, wodach powierzchniowych i ściekach; metoda ta może być także odpowiednia do oznaczania innych związków organicznych. Określono wymagania aparaturowe. W załącznikach informacyjnych podano tablicę zawierającą wykaz związków fosforoorganicznych i ich odzysku oraz tablice wyników oznaczania dla kilku rodzajów wód" [Methods of extraction and chromatographic analysis (GC) used for the determination of parathion, methyl parathion and some other organophosphorus compounds in drinking water, surface water and wastewater are presented; the method may also be suitable for the determination of other organic compounds. Requirements for the apparatus are specified. The informative annexes give a table listing the organophosphorus compounds and their recoveries, and tables of determination results for several types of water]. The Polish edition was published on 8 July 2004, has 26 pages and is maintained by KT 122 Water Quality — Chemical Testing — Organic Substances, ICS 13.060.50; it implements EN 12918:1999 and replaces PN-EN 12918:2002 in the English-language version.

ONE ITEM OF THE REGULATION, TWO STANDARDS. The regulation of the Minister of Maritime Economy and Inland Navigation of 12 July 2019 (Journal of Laws 2019 item 1311) lists in Annex No. 12, under item 33 "Insektycydy fosforoorganiczne" [organophosphorus insecticides], one technique — gas chromatography — and two standards: PN-EN 12918 and PN-EN ISO 10695. The card of the second one gives the title "Jakość wody — Oznaczanie wybranych związków azoto- i fosforoorganicznych — Metody chromatografii gazowej" [Water quality — Determination of selected organic nitrogen and phosphorus compounds — Gas chromatographic methods] and the scope: determination in drinking water, groundwater, surface water and wastewater by gas chromatography with an N/P detector, after liquid–solid or liquid–liquid extraction. Polish edition of 6 August 2004, 29 pages; the card gives no withdrawal date (state of the card on 23.09.2026).

WHO CITES PN-EN 12918. Measurement on the copy of the accreditation scopes (reading of 23.09.2026; all notations of the number in the reference-document field are counted — neither a digit nor a letter may stand before the number, and no digit after it): four laboratories, six entries. AB 079 — "Stężenie pestycydów" [pesticide concentration]; AB 213 — two entries: "Stężenie pestycydów fosforoorganicznych" [organophosphorus pesticide concentration] and "Suma pestycydów fosforoorganicznych (z obliczeń)" [sum of organophosphorus pesticides (calculated)]; AB 300 — two entries, for water and for wastewater, "Stężenie związków fosforoorganicznych" [organophosphorus compound concentration] with a list of substances; AB 418 — "Stężenie pestycydów fosforoorganicznych". Five entries have the notation "PN-EN 12918:2004", one (AB 418) — "PN-EN 12918" without a year. The "Laboratories" tab searches for notations beginning with "PN-EN 12918" and shows all six.

NOBODY CITES THE OTHER STANDARD. PN-EN ISO 10695 does not occur in the accreditation scopes even once. There are eight entries in the whole set, at five laboratories, in which the test name or a parameter names organophosphorus compounds. Six of them are the entries with PN-EN 12918 described above; the other two belong to AB 005, which cites other standards for them: PN-EN ISO 6468 (excluding clause 7.2) and PN-EN ISO 11369. PN-EN ISO 10695 stands next to none of them. For comparison: PN-EN ISO 6468 — a standard that the same annex indicates, among others, for the other insecticides from the group of chlorinated hydrocarbons (item 32) — has 21 laboratories and 42 entries in the scopes (the same measure: all notations of the number).

WHAT THESE NUMBERS SAY. They say how many laboratories have this determination in their accreditation scope and according to which standard. They say nothing about the quality of the tests or about why laboratories chose this standard rather than the other one from the item of the regulation.

WHAT WE DO NOT GIVE. We did not have the text of the standard — PKN makes it available for a fee (26 pages). The title speaks of dichloromethane extraction and gas chromatography, the card — of requirements for the apparatus (without their content) and of a table of recoveries in an informative annex. We do not give the detector, the columns, the way the extract is dried and concentrated or the recovery values.

Method principle

According to the title and the card of the standard: organophosphorus compounds are extracted from water with dichloromethane and determined by gas chromatography (GC). The standard specifies requirements for the apparatus and gives in its informative annexes a table of organophosphorus compounds with their recoveries and tables of determination results for several types of water; the method may also be suitable for other organic compounds. WE DO NOT GIVE the detector, the columns or the separation conditions — we did not have the text of the standard.

Applications

• Drinking water, surface water and wastewater — scope of the standard according to the card
• Testing of wastewater for the purposes of Journal of Laws 2019 item 1311 — one of the two standards listed for organophosphorus insecticides (Annex No. 12, item 33)

Key parameters

Standard

Standard number

PN-EN 12918:2004

Title (PL)

Jakość wody — Oznaczanie parationu, parationu metylowego i kilku innych związków fosforoorganicznych w wodzie metodą chromatografii gazowej po ekstrakcji dichlorometanem

Title (EN)

Water quality — Determination of parathion, methylparathion and some other organophosphorus compounds in water by dichloromethane extraction and gas chromatographic analysis

Step-by-step procedure

1. Extraction

   The organophosphorus compounds are extracted from the sample with dichloromethane (title of the standard). WE DO NOT GIVE the volumes, the number of extractions or the conditions.

2. Chromatographic separation

   Gas chromatography (title of the standard); WE DO NOT GIVE the separation and detection conditions.

3. Recovery

   The standard gives a table of recoveries for the list of compounds in an informative annex (card); only the holder of the text of the standard knows the values.

4. Entry in the report

   List the compounds determined: the standard covers parathion, methyl parathion and "some others", so its number alone does not say which of them were determined.

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• Dichloromethane — the solvent indicated in the title of the standard; hazards and protective measures according to the supplier's safety data sheet (this entry does not quote them)

Frequently asked questions