Ahmed M T, Ismail S M, Mosleh Y Y
Suez Canal University, Faculty of Agriculture, Plant Protection Department, Ismailia, Egypt.
J AOAC Int. 1998 Sep-Oct;81(5):1023-6.
A method for determining malathion residues by reversed-phase liquid chromatography (LC) using methanol only as mobile phase is described. Malathion [diethyl(dimethoxyphosphinothiol)succinate] was applied on marjoram, mint, and chamomile. Residues were detected in fresh and dry crops by LC and confirmed by gas-LC/mass spectrometry. Average recovery of malathion was 85%. Residues detected in fresh marjoram, mint, and chamomile were 0.18, 0.23, and 0.083 mg/kg, respectively. Residues detected in dry marjoram and mint were 0.024 and 0.050 mg/kg, respectively. No malathion residues were detected in dry chamomile. The minimum detectable concentration with this method is 0.013 mg/kg. The study suggests it is safe to use malathion up to 2 sprays per season provided the crop is harvested not less than 3 weeks from the last spray.
描述了一种仅使用甲醇作为流动相通过反相液相色谱法（LC）测定马拉硫磷残留量的方法。马拉硫磷[二乙基（二甲氧基硫代磷酰基）琥珀酸酯]施用于马郁兰、薄荷和洋甘菊上。通过液相色谱法在新鲜和干燥作物中检测残留量，并通过气相色谱-质谱联用仪进行确证。马拉硫磷的平均回收率为85%。在新鲜的马郁兰、薄荷和洋甘菊中检测到的残留量分别为0.18、0.23和0.083毫克/千克。在干燥的马郁兰和薄荷中检测到的残留量分别为0.024和0.050毫克/千克。在干燥的洋甘菊中未检测到马拉硫磷残留量。该方法的最低检测浓度为0.013毫克/千克。该研究表明，只要作物在最后一次喷洒后不少于3周收获，每季最多喷洒2次马拉硫磷是安全的。
