Determination of carbendazim in soil and lake water by immunoaffinity extraction and coupled-column liquid chromatography tandem mass spectrometry

A method employing a high-performance protein G immunoaffinity column coupled to a reversed-phase analytical column through the use of a trapping column and INTEGRAL Micro-Analytical Workstation for the extraction of carbendazim from lake water samples and soil extracts is described. Characterization of the target analyte is achieved by on-line mass spectrometric analysis. The specificity of immunoaffinity extraction makes it possible to detect low levels of carbendazim in soil samples without interference from matrix components. The use of selected reaction monitoring allows for the achievement of the highest possible sensitivity with a minimum of chemical interference. Carbendazim is enriched from soil extracts at the 100 ppb level. It is possible to detect trace levels (25 pptr) of carbendazim in lake water samples. This is probably due to fewer matrix interferences in water than in soil. Very little sample preparation is required for environmental water samples while a liquid-solid extraction method is required prior to immunoaffinity extraction for soil samples. The ability to pump sample through the protein G column at high flow-rates (10 ml/min) and to automate the column-switching procedure makes the method rapid and efficient. Multiple samples can be analyzed in a relatively short period of time with minimum sample preparation. With the described protocol, three soil or water samples can be analyzed per hour without operator intervention. (C) 1997 Elsevier Science B.V.