Department of Chemistry & Physics, CCS Haryana Agricultural University, Hisar, 125 004, India.
Bull Environ Contam Toxicol. 2012 Mar;88(3):352-7. doi: 10.1007/s00128-011-0483-9. Epub 2011 Dec 15.
Persistence behaviour of λ-cyhalothrin in tomato fruits was studied following application with recommended (15 g a.i. ha(-1)) and double the recommended (30 g a.i. ha(-1)) dosage of λ-cyhalothrin at fruiting stage under two different temperature conditions. Samples were collected on 0 (1 h after spray), 1, 3, 5, 7, 10 and 15 days after application. Effects of processing like washing, washing followed by boiling were studied to dislodge the residues of λ-cyhalothrin on tomato fruits. Residues were estimated by GC-ECD capillary system. Residues of λ-cyhalothrin persisted up to 7 days in tomato fruits. The half-life (t (1/2)) periods were observed to be 2.07 and 1.88 days at room temperature and 2.35 and 2.02 days under refrigerated condition for single and double dose, respectively. The process of washing followed by boiling reduced the residues effectively (74-84%) whereas by washing only, residues could be reduced in the range of 37-40%. In samples under refrigerated condition, residues decreased slightly less than the samples stored under room temperature. Washing followed by boiling reduced the residues from 72 to 80% whereas only washing reduced the residues from 35 to 36% In soil samples, residues of λ-cyhalothrin reached below detectable level of 0.005 mg kg(-1) on 3rd and 7th day at single and double dose, respectively.
在番茄结果期，按照推荐剂量（15 g a.i. ha(-1)）和推荐剂量的两倍（30 g a.i. ha(-1)）用 λ-氯氟氰菊酯对番茄进行喷雾处理，在两种不同温度条件下研究了 λ-氯氟氰菊酯在番茄果实中的持留行为。分别在施药后 0（施药后 1 h）、1、3、5、7、10 和 15 天采集样本。研究了清洗、清洗后煮沸等处理方法对去除番茄果实上 λ-氯氟氰菊酯残留的效果。采用 GC-ECD 毛细管系统对残留量进行了估计。在番茄果实中，λ-氯氟氰菊酯的残留量可长达 7 天。在室温下，单剂量和双剂量的半衰期（t (1/2)）分别为 2.07 和 1.88 天，在冷藏条件下分别为 2.35 和 2.02 天。清洗后煮沸的处理方法能有效降低残留量（74-84%），而仅清洗的残留量降低幅度在 37-40%之间。在冷藏条件下的样本中，残留量比在室温下储存的样本减少略少。清洗后煮沸能使残留量从 72%降至 80%，而仅清洗则使残留量从 35%降至 36%。在土壤样本中，单剂量和双剂量分别在第 3 天和第 7 天降至无法检测到的 0.005 mg kg(-1)以下。
