Analysis of the plant growth regulator chlormequat in soil and water by means of liquid chromatography-tandem mass spectrometry, pressurised liquid extraction, and solid-phase extraction.

We present a new, precise and accurate method for quantitative analysis of chlormequat in soil and aqueous matrices. The method, which is based on LC-MS/MS, pressurised liquid extraction and solid-phase extraction, is eminently suitable for studying the fate of chlormequat in the soil environment. The limit of detection is 0.003-0.008 microg/L for rainwater, surface water and groundwater and 0.07-0.4 microg/kg for soil. In water samples amended to 0.04 microg/L, precision is better than 10%. The residual content of chlormequat in three agricultural topsoils analysed 4 months after its application was 23-55 microg/kg (12-23% of the amount applied). No trace of chlormequat was detected in groundwater from 66 water supply wells located in rural areas treated with chlormequat.