Residual determination and risk assessment of buprofezin in plum (Prunus domestica) grown in open‐field conditions following the application of three different formulations

This study was conducted to characterize the residual level and perform a risk assessment on buprofezin formulated as an emulsifiable concentrate, wettable powder, and suspension concentrate over various treatment schedules in plum (Prunus domestica). The samples were extracted with an AOAC quick, easy, cheap, effective, rugged, and safe, ‘QuEChERS’, method after major modifications. As intrinsic interferences were observed in blank plum samples following dispersive‐solid phase extraction (consisting of primary secondary amine and C₁₈ sorbents), amino cartridges were used for solid‐phase extraction. Analysis was carried out using liquid chromatography with diode array detection and confirmed by liquid chromatography–tandem mass spectrometry. The method showed excellent linearity with determination coefficient (R² = 1) and satisfactory recoveries (at two spiking levels, 0.5 and 2.5 mg/kg) between 90.98 and 94.74% with relative standard deviation (RSD) ≤8%. The limit of quantification (0.05 mg/kg) was considerably lower than the maximum residue limit (2 mg/kg) set by the Codex Alimentarius. Absolute residue levels for emulsifiable concentrates were highest, perhaps owing to the dilution rate and adjuvant. Notably, all formulation residues were lower than the maximum residue limit, and safety data proved that the fruits are safe for consumers. Copyright © 2016 John Wiley & Sons, Ltd.     

茶叶中噻嗪酮残留量的GC-MS测定

采用样品处理的微量化学法和固相萃取技术,建立了茶叶中噻嗪酮残留量的GC -MS测定方法 ;用丙酮 -正己烷 (体积比1∶1)萃取 ,活性碳和中性氧化铝小柱净化 ,净化液用GC -MS测定,外标法定量 ;方法回收率在88%～109 %之间,相对标准偏差为2 %～4 %,测定限为0.010×10-6(w);该法快速、灵敏、准确 ,各项技术指标均满足残留量检测的要求。     

多壁碳纳米管固相微萃取测定水中的三唑酮和噻嗪酮

将多壁碳纳米管涂在不锈钢丝上制作了固相微萃取探头,利用固相微萃取-气相色谱-质谱联用技术测定湖水中的三唑酮和噻嗪酮。对萃取温度、萃取时间及离子强度等影响萃取效率的因素进行了优化。在优化的条件下,通过加标水样的分析对方法进行了评估。结果表明,方法的线性范围为25—150μg/L,相关系数为0.9922—0.9982,三唑酮和噻嗪酮的检出限（LOD,S/N=3）分别为2.21ng/L和0.18ng/L。湖水的加标回收率在84%—110%之间,相对标准偏差小于10.8%。     

Fourier transform infrared spectrometric strategies for the determination of Buprofezin in pesticide formulations

Two different strategies for Buprofezin determination, an off-line extraction and stopped-flow determination and an automated procedure, based on the on-line extraction of Buprofezin samples with chloroform and flowing action analysis-fourier transform infrared (FIA-FT-IR) spectrometric measurement of the extracts, have been developed. For the treatment of the off-line extraction mode, data a three-factor partial least squares (PLSs) calibration was developed, using the region from 1465.7 to 1342.3 cm⁻¹ with a single point baseline defined at 2051.9 cm⁻¹ and based on the use of chloroform solutions of Buprofezin. The method provides a R.S.D. <0.1%, recoveries of the order of 100% and generates 25 ml of CHCl₃ waste for each sample.On the other hand, the recommended FIA method provided a 3 s limit of detection of 20 μg ml⁻¹, which corresponds to 0.12% (w/w) in the solid sample, a repeatability of 0.8% as R.S.D., and a maximum sampling frequency for the whole procedure of 6 h⁻¹.The waste generation, being lower than the off-line strategy, is only 3 ml of CHCl₃ per sample.     

农药噻嗪酮在玻碳电极上的电化学行为

应用循环伏安法(CV)、线性扫描伏安法(LSV)、微分脉冲伏安法(DPV)和方波伏安法(SWV)等研究了噻嗪酮在玻碳电极上的电化学行为,并建立样品噻嗪酮的SWV测定法.噻嗪酮在玻碳电极上的电还原涉及两质子/两电子和两质子的不可逆过程.     

茶叶中噻嗪酮残留量的气相色谱测定

建立了用配有氮磷检测器(NPD)的气相色谱仪来测定茶叶中噻嗪酮的方法;试样用丙酮水提取,正己烷反萃取,florisi1加少量活性炭柱净化,以GC-NPD方式测定,外标法定量,必要时经质谱确证;该法准确,精密度好,杂质干扰少;测定限为0.01×10-6(w).     

噻嗪酮与牛血清白蛋白相互作用的光谱法研究

用荧光光谱和紫外光谱,在模拟生理条件下研究噻嗪酮与牛血清白蛋白(BSA)的相互作用.研究发现,噻嗪酮与牛血清白蛋白的猝灭机制为静态猝灭;298 K、303 K和308 K时的结合常数分别1.80×103、1.54×103和1.05×103L·moL-1,结合位点数n近似为1;由热力学参数推测噻嗪酮与牛血清白蛋白间结合力...