Fe3O4/reduced graphene oxide nanocomposites based dispersive solid phase microextraction for trace determination of profenofos in white rice flour samples

In this study, an easy and efficient microextraction strategy for the preconcentration and extraction of profenofos at trace levels prior to high performance liquid chromatography with ultraviolet detector and gas chromatography-flame ionization detector systems have been established. Fe₃O₄/reduced graphene oxide nanocomposites based dispersive solid phase microextraction (DSPME) was used to extract and enrich the analyte from white rice flour samples. After obtaining good chromatographic separation on high performance liquid chromatography with ultraviolet detector and gas chromatography-flame ionization detector systems, all DSPME parameters were adjusted to their optimum conditions by univariate approach. Under the optimum conditions, limit of detection values for DSPME coupled to high performance liquid chromatography with ultraviolet detector and DSPME coupled to gas chromatography-flame ionization detector systems were found to be 14.2 and 34.2 ng/g, respectively. Spiking experiments were also done in order to examine the method applicability and accuracy. Relative recovery results for white flour sample were found to be between 96.6–103.4 % for each system. The developed methods were successfully applied to five different brands of the flour samples.     

Evaluation of the Acute Toxicity of Profenofos and Its Effects on the Behavioral Pattern of Fingerling Common Carp (C<Emphasis Type="Italic">yprinus carpio</Emphasis> L., 1758)

Profenofos, an organophosphate insecticide is acetylcholinesterase inhibitor that has the potential to contaminate the ground water. The 96 h LC₅₀ value of profenofos was determined in 3-month-old fingerling common carp (Cyprinus carpio) with a body weight 1.04 ± 0.25 g and a body length 4.25 ± 0.75 cm at 26 ± 1°C temperature. Trimmed Spearman-Karber (TSK) software was used for the statistical analysis, which calculated the LC₅₀ value as 62.4 μg/L for three replicates of the assay. The behavioral responses of fish exposed to profenofos included loss of balance, moving in spiral fashion with sudden jerky movements, lying on their sides and rapid flapping of the operculum with the mouth open.     

血液中丙溴磷检测方法研究

目的研究血液中有机磷农药的气相色谱测定方法，完善检测过程，优化检测条件，建立简便高效的提取净化方法和准确、快速、灵敏的色谱检测方法。方法将中毒血样经乙酸乙酯萃取后，用毛细管气相色谱法测定其含量。结果分析方法的检出限为0．8ng，低、中、高三种浓度的加标回收率为95．4％±5．85％、91．2％±11．5％、92．8％±5．5％。结论该方法灵敏、准确、可靠，适合人血液中丙溴磷的检测。     

丙溴磷对家兔周围神经传导功能的影响

目的　探讨丙溴磷对家兔周围神经传导功能的影响。方法　将家兔随机分为 2个染毒组 [高剂量染毒组丙溴磷剂量为 0 0 8g/(kg·d) ,低剂量染毒组丙溴磷剂量为0 0 2 g/(kg·d) ]和 1个对照组 (丙酮 ) ,经皮肤染毒。于染毒前和染毒第 5天、第 1 0天对各组家兔分别进行神经 -肌电图描记 ,记录传导速度、远端潜伏时、近端潜伏时等指标 ;测定各组血清ChE活力。结果　 2个染毒组家兔血清ChE活力均下降 ,高剂量染毒组在染毒开始后的第 5天、第 1 0天ChE活力与正常值的比值分别为 5 6 2 % ,4 2 6 % ,低剂量染毒组在染毒开始后的第 5天、第 1 0天ChE活力与正常值的比值分别为 86 1 % ,72 6 % ,均显著低于相应的对照组 (P <0 0 5 ,P <0 0 1 )。与染毒前和对照组比较 ,在染毒的不同时间 ,染毒组的神经传导速度明显减慢 ,同时远端潜伏时、近端潜伏时显著延长 (P <0 0 5 ,P <0 0 1 )。结论　丙溴磷可致周围神经传导功能损害。这种损害在ChE活力比正常值的 70 %高的低剂量组即已出现 ,表明周围神经传导功能损害可能早于胆碱酯酶活力的抑制