Home
Resources
Publications
Methylation Protocol for the Retrospective Detection of Isopropyl-, Pinacolyl- And Cyclohexylmethylphosphonic Acids, Indicative Markers for the Nerve Agents Sarin, Soman and Cyclosarin, at Low Levels in Soils Using EI-GC-MS

Methylation Protocol for the Retrospective Detection of Isopropyl-, Pinacolyl- And Cyclohexylmethylphosphonic Acids, Indicative Markers for the Nerve Agents Sarin, Soman and Cyclosarin, at Low Levels in Soils Using EI-GC-MS

Carlos A Valdez, Roald N Leif, Saphon Hok, Alexander K Vu, Edmund P Salazar, Armando Alcaraz

Sci Total Environ. 2019 Sep 15;683:175-184.

PMID: 31146057

Abstract:

A practical and efficient protocol for the derivatization and detection by GC-EI-MS of isopropyl-, pinacolyl- and cyclohexylmethylphosphonic acids, key diagnostic degradation products of the nerve agents sarin, soman and cyclosarin respectively, in six different types of soil matrices is presented. The method involves the in situ conversion of the phosphonic acids to their respective methyl esters using trimethyloxonium tetrafluoroborate when present in the soils at low levels (10 μg g-1) without any prior extractions or soil preparation. The soils employed in our study were Nebraska EPA soil, Georgia soil, silt, Virginia type A soil, regular sand and Ottawa sand and were chosen for their vast differences in composition and physical features. Appealing attributes of the protocol include its rapidity (t < 30 min), mildness (ambient temperature), and practicality that includes the production of the phosphonic methyl esters that can be easily detected by GC-EI-MS and corroborated with the instrument's internal NIST spectral library or the Organisation for the Prohibition of Chemical Weapons (OPCW) central analytical database (OCAD v.21_2019). The overall efficacy of the protocol was then tested on a soil sample featured in the 44th OPCW PT that our laboratory participated in. After preparing the soil so as to give pinacolyl methylphosphonic acid at a 5 μg g-1 concentration, the acid was successfully methylated and detected by GC-EI-MS. The protocol's performance mirrors that of the universally employed diazomethane protocol but accomplishes this without any of the explosive hazards and time consuming reagent preparation commonly associated with it.

Chemicals Related in the Paper:

Catalog Number	Product Name	Structure	CAS Number	Price
IAR42162	Gasoline in Soil - PT			Price

As a specialist in analytical chemical Products, Alfa Chemistry offers consumers a wealth of raw materials and a full range of technologies and services.

QUICK LINKS

HEADQUARTERS

Tel:

Fax:

Email: