The potential of ICP-MS as an elemental specific detector for capillary electrophoresis separation of pesticides

WUILLOUD, RODOLFO G.; SHAH, MONIKA; KANNAMKUMARATH, SASI S.; CARUSO, JOSEPH A.

Fort Lauderdale, Florida

Conferencia; 2004 WINTER CONFERENCE ON PLASMA SPECTROCHEMISTRY; 2004

WINTER CONFERENCE ON PLASMA SPECTROCHEMISTRY

Pesticide use in agricultural activities progressively increased after World War II leading to increased world food production. Organophosphorus pesticides (OPPs) are widely used in the US by farmers and in the formulation of various home pesticide repellent products. An immediate consequence of the acute exposure is to affect the nervous system by reducing the regulatory effect of cholinesterase on acetylcholine, which could lead to paralysis of muscles. Since the OPPs are intensively employed in US for a variety of purposes, there is high potential for human exposure. This may occur through contaminated drinking water or by eating contaminated food and vegetable products.Determination of pesticides in pesticide formulations, food, and in complex environmental matrices, often requires a separation method of high efficiency, unique selectivity and high sensitivity. Capillary electrophoresis (CE) can fulfill these requirement and has proved to be a suitable microseparation technique for the analysis of a wide variety of pesticides.1, 2 The potential of inductively coupled plasma mass spectrometry (ICP-MS) for the detection of organophosphorus and organosulfur pesticides after previous separation by CE is shown in this work. The addition of different optional gases in the argon plasma to improve the sensitivity of ICP-MS for phosphorus and sulfur determination was studied. Additionally, the use of different gases in the octapole reaction system was investigated to improve phosphorus and sulfur sensitivity. Other parameters involved in the separation and detection of these compounds were evaluated in order to obtain optimal analytical performance characteristics. (1) Pico, Y.; Rodriguez, R.; Manes, J. Trac-Trends in Analytical Chemistry 2003, 22, 133-151.(2) Malik, A. K.; Faubel, W. Critical Reviews in Analytical Chemistry 2001, 31, 223-279.