抄録
A fully automated method for determination of imidazolinone pesticides in tap and mineral waters is proposed. The automation of the flow assembly is based on the multi-commutation approach, which uses multiple solenoid actuated micro-solenoid devices strategically positioned in the flow manifold. The determination of imazapyr, imazaquin and imazamethabenz-methyl is performed on the basis of the photodegradation of pesticides by using a photoreactor consisting of 150 cm x 0.8 mm PTFE tubing helically coiled around a 20 W low-pressure mercury lamp. UV irradiation of imidazolinone pesticides (270s) turns into strong chemiluminescent photoproducts in presence of potassium permanganate as oxidant. The method is linear up to 10 mg L-1 for all imidazolinones; the limit of detection and reproducibility (as the RSD of 10 peaks of a 0.5 mg L-1 solution) are 0.05 mg L-1 and 1.3 % (imazapyr), 0.1 mg L-1 and 2.2 % (imazaquin), and 0.01 mg L-1 and 1.4 % (imazamethabenz-methyl). The sample frequency is 12 h-1.
