摘要
采用气相色谱测定代森锰锌和代谢物乙撑硫脲,最小检出量分别是1.125×10-10g和6.82×10-10g;最小检出浓度0.003mg·kg-1和0.014mg·kg-1;回收率90.6%～97.8%和89.2%～98.2%。结果表明,香蕉和土壤中的残留量与施药剂量、次数呈正相关,与等收期呈负相关,本试验条件下,最高剂量150倍,最多施4次,等收期7d,在香蕉皮中的最终残留量为0.641～0.670mg·kg-1,代森锰锌在蕉肉中和乙撑硫脲在香蕉、土壤中残留量均未检出。在香蕉中的残留量低于FAO/WHO规定的CS2=1mg·kg-1、ETU=0.1mg·kg-1。据此,推荐生产上用42%代森锰锌SC,300～400倍,喷施2～4次,每次间隔7～10d,最后1次距收期7～14d,是安全的。
In order to evaluate the safety of mancozeb in banana and soil, a field experiment was conducted to reveal the residual dynamics and final residues of mancozeb and its metabolite ethylenethiourea （ETU） in banana and soil by GC. The minimum detectable amount by the GC method were 1.125×10^-10 g and 6.82×10^-10 g, the minimum detectable concentration were 0.003 mg·kg^-1 and 0.014 mg·kg^-1, and the average recovery rates were 90.6%-97.8% and 89.2%-98.2% in banana and soil respectively. The experiment indicated that the degradation of mancozeb and ETU in banana and soil was in accordance with a dynamic equation C=C0e^-kt, with the half life of mancozeb and ETU being 3.3-3.4 d in banana, 5.3-5.9 d in soil, respectively. After 7 days of application, the final residue in banana was 0.641 0-0.670 4 mg·kg^-1 with 150 times dilution and spraying four times, the residual mancozeb in banana pulp, ETU in banana and soil were all lower than their detection limits. Therefore, based on the FAO/WHO MRL of mancozeb and ETU in banana, 1 mg·kg^-1 and 0.1 mg·kg^-1, the recommended dosage with 300-400 times dilution and spraying 2-4 times of 42% manlozeb SC was safe.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2008年第3期1194-1198,共5页
Journal of Agro-Environment Science
基金
农业部"九五"项目
