柑橘中除虫脲的残留及膳食安全风险评估

Residue and dietary safety risk assessment of diflubenzuron in citrus

2018年,在湖南的长沙和张家界、浙江兰溪等12个地点开展除虫脲的最终残留试验,并在湖南长沙、江西高安、广西南宁、福建漳州等4地进行除虫脲的残留消解动态试验,采用高效液相色谱-串联质谱法(HPLC-MS/MS)测定除虫脲在柑橘全果和果肉中的残留量,并进行除虫脲的膳食安全风险评估。柑橘样品先采用乙腈超声提取,再经PSA和无水硫酸镁净化,最后用HPLC-MS/MS分析测定,外标法定量,柑橘全果和果肉中除虫脲的添加水平为0.01、0.10、1.00、5.00mg/kg时,平均回收率分别为89%~102%和76%~99%,相对标准偏差分别为7%~11%和8%~9%;除虫脲在柑橘全果和果肉中的定量限均为0.01 mg/kg;除虫脲在柑橘全果和果肉中的残留量随着时间的推移呈波动性缓慢下降,其消解半衰期分别为13.0~18.0 d和9.6~34.0 d;质量分数25%除虫脲可湿性粉剂在柑橘上以125 mg/kg(制剂用量为2000倍液)施药3次,施药间隔7 d,于末次施药后第35天采样测定,除虫脲在柑橘全果和果肉中的残留量分别为<0.01~0.55 mg/kg和<0.01~0.93 mg/kg,除虫脲在柑橘中的残留量均小于中国规定的最大残留限量值(1 mg/kg);膳食安全风险评估结果显示,普通人群中除虫脲的国家估算每日摄入量为0.6512 mg(柑橘全果)、0.6444 mg(柑橘果肉),风险商为51.7%(柑橘全果)、51.1%(柑橘果肉),对一般人群健康产生的风险较低。

The final residue experiment of diflubenzuron in citrus(Citrus reticulata Balanco)was carried out in twelve cities(Changsha,Zhangjiajie,Lanxi,etc)in China in 2018.And the residue dissipation dynamics experiment of diflubenzuron was studied in Changsha,Gaoan,Nanning and Zhangzhou.The residue of diflubenzuron in citrus whole fruit and pulp were investigated by high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)method,and then the risk assessment for dietary safety risk of diflubenzuron in citrus was studied based on the residue data.The results showed that citrus samples were first extracted with acetonitrile ultrasonically,then purified by PSA and anhydrous magnesium sulfate,and finally detected by HPLC-MS/MS,the external standard method was used for quantification.The average recoveries of diflubenzuron in citrus whole fruit and pulp at the spiked level of 0.01,0.10,1.00 and 5.00 mg/kg were 89%-102%and 76%-99%,respectively;and the relative standard deviations were 7%-11%and 8%-9%,respectively.The limits of quantitation of diflubenzuron in citrus whole fruit and pulp were both 0.01 mg/kg.The residues of diflubenzuron in citrus whole fruit and pulp decreased slowly over time.The dissipation half-lives of diflubenzuron in citrus whole fruit and pulp were 13.0-18.0 d and 9.6-34.0 d,respectively.The mass fraction 25%wettable powder of diflubenzuron was sprayed at doses of 125 mg/kg(2000 times of the liquid)for 3 times on citrus with an interval of 7 d.Then samples were collected and determined at 35 days after the last application.The residues of diflubenzuron were<0.01-0.55 mg/kg in citrus whole fruit and<0.01-0.93 mg/kg in citrus pulp,respectively,which were both lower than provisions of maximum residue limit(1 mg/kg).The result of dietary safety risk assessment revealed that the national estimated daily intake of diflubenzuron were 0.6512 mg in citrus whole fruit and 0.6444 mg in citrus pulp,accounting for 51.7%and 51.1%of the acceptable daily intake respectively,which indicates a low risk from long-term dietary intake in the general population.