Examining the feasibility of mixture risk assessment: A case study using a tiered approach with data of 67 pesticides from the Joint FAO/WHO Meeting on Pesticide Residues (JMPR)

The way in which mixture risk assessment (MRA) should be included in chemical risk assessment is a current topic of debate. We used data from 67 recent pesticide evaluations to build a case study using Hazard Index calculations to form risk estimates in a tiered MRA approach in line with a Framework proposed by WHO/IPCS. The case study is used to illustrate the approach and to add detail to the existing Framework, and includes many more chemicals than previous case studies.A low-tier MRA identified risk as being greater than acceptable, but refining risk estimates in higher tiers was not possible due to data requirements not being readily met. Our analysis identifies data requirements, which typically expand dramatically in higher tiers, as being the likely cause for an MRA to fail in many realistic cases. This forms a major obstacle to routine implementation of MRA and shows the need for systematic generation and collection of toxicological data. In low tiers, hazard quotient inspection identifies chemicals that contribute most to the HI value and thus require attention if further refinement is needed. Implementing MRA requires consensus on issues such as scope setting, criteria for performing refinement, and decision criteria for actions.     

DNA条形码技术在陕西省鼠疫疫区宿主动物鉴定中的应用

目的 探讨DNA条形码技术在鼠疫疫区宿主动物鉴定中的应用,并建立陕西省鼠疫疫区宿主动物DNA条形码数据库.方法 运用DNA条形码技术检测陕西省定边县鼠疫疫区3目6科12属14种139只宿主动物以及7个鼠种8个不同部位的62份残体标本线粒体细胞色素C氧化酶Ⅰ亚基基因序列.结果 种内遗传距离≤2％,种间遗传距离为8.9％～ 15.1％;邻接法系统树能区分14个不同物种的类群;采集的残体标本能检测到目的基因并用于鉴定;研究中还纠正了既往定边县鼠疫疫区黄鼠命名.结论 DNA条形码技术能弥补形态学鉴定的不足,可用于鼠疫疫区宿主动物及残体标本的分类鉴定.     

二次电切在非肌层浸润性膀胱癌的临床价值

目的 探讨二次电切在非肌层浸润性膀胱癌的应用价值.方法 回顾性分析我院37例非肌层浸润性膀胱癌患者的临床资料,所有患者进行首次电切后6周内进行二次电切,观察首次电切后的肿瘤残留情况、两次电切时的手术情况及二次电切后患者的无瘤生存状况.结果 首次电切及二次电切的手术时间分别为[（67.4±12.5）min vs （55.8±8.4）min,t=5.167,P＜0.01]、留置导尿管时间分别为[（9.8±2.1）d vs（9.4±1.9）d,t=0.730,P=0.468],首次电切后有6例患者（16.2％）存在肿瘤残留,3例患者（8.1％）出现肿瘤分期升高,其中1例由T1期肿瘤上升至T2期,2例患者由Ta期肿瘤上升至T1期;二次电切后在5～7年的长期随访中,复发10例（27.0％）,具体为术后的第13、16、19、21、29、42、58、66、73、76个月,随访期间共3例患者死亡,死亡原因与膀胱肿瘤无关.结论 二次电切可有效的发现肿瘤残留并及时处理,提高无瘤生存时间.     

GC法测定三七三醇皂苷中8种大孔吸附树脂的残留物

目的 采用顶空气相色谱法同时测定三七三醇皂苷中8种大孔吸附树脂的残留物.方法 色谱柱为Agilent innowax 柱(30m×0.32 mm,0.5 μm),二甲亚砜为溶解介质,FID检测器,进样口温度140 ℃,检测器温度250℃,高纯氮作载气,程序升温(50℃保持20 min,再以6℃·min-1升至165℃,保持20 min).结果 各组分在所考察的浓度范围内均具有良好的线性,r为0.9903 ～0.9998,RSD为1.13％ ～6.99％,正己烷、环己烷、1,1,1-三氯乙烷、苯、甲苯、邻二甲苯、间二甲苯、对二甲苯的最低检出浓度分别为0.1389、0.3056、6.4980、0.5528、0.8282、1.9962、1.9500、2.6900 mg· kg-1.结论 所用方法快速、灵敏、准确,适用于三七三醇皂苷中大孔吸附树脂残留物的测定.     

呼和浩特市市售银耳二氧化硫残留量监测结果分析

目的:监测呼和浩特市流通领域银耳二氧化硫残留状况,为呼和浩特市食品安全监管提供科学依据。方法:按照随机抽样原则在呼和浩特市大型超市、批发市场(包括个体零售点)随机抽取银耳样品,依照相应国家标准进行检测和评价。结果:呼和浩特市连续两年监测的42份银耳二氧化硫残留量总超标率为52.38%,其中来源于大型超市、批发市场(包括个体零售点)的超标率分别是20.00%和81.82%;定型包装和散装的样品超标率分别是19.05%和85.71%。结论:呼和浩特市流通领域银耳二氧化硫残留量超标较严重,有关部门应加强监管监测。     

荧光法快速测定鸡血清中环丙沙星的残留量

目的建立快速测定鸡血清中环丙沙星(Cpfx)残留量的方法。方法采用荧光光度法。结果用甲醇沉淀蛋白对血清进行预处理,利用Cpfx-Al3 -CTMAB体系,鸡血清中Cpfx浓度在1.00~3.00μg.ml-1范围时,荧光强度与浓度呈线性关系,其回归方程为:F=37.6201 14.1576C(r=0.9991),平均回收率为100.4%,RSD=0.22%。结论所用方法简便、准确、快速,可用于鸡血清中环丙沙星的测定。     

The Development of a Rapid Immunobiosensor Screening Method for the Detection of Residues of Sulphadiazine

A rapid immunoassay using an optical biosensor (BIAcoreTM) for determining the presence of sulphadiazine (SDZ) residues in pig bile was developed. SDZ was immobilised onto the surface of a dextran-coated silicon chip and a solution containing SDZ antibody, sample and buffer was injected over the chip surface. The level of antibody binding to the chip was determined after 20 s and the surface of the chip was then regenerated over a 1-min period prior to another sample injection taking place. Standard curves were constructed to allow quantification of SDZ presence in sample. Concentrations ranging from 0 to 10.64 mu g ml-1 SDZ were detected in bile samples taken from experimentally fed pigs and randomly selected pigs taken from a local slaughterhouse. These results were compared to the concentrations of SDZ detected by high-performance liquid chromatography in associated tissues. When concentrations in bile exceeded 0.6 mu g ml-1 SDZ, the corresponding edible tissue was above the maximum residue level (MRL), i.e. 0.1 mu g g-1 in 13 out of 14 cases. When the bile concentration was less than 0.6 mu ml-1 the associated tissue concentrations never exceeded the MRL. This experiment has indicated that biosensor analysis of bile is a highly effective method for detecting violative SDZ residues in meat.     

基于专利分析的硒医药技术发展研究

近年,中药中农药残留污染问题引起广泛关注。在“一带一路”战略背景下,甘肃省中药材的出口贸易快速增长,同时农药残留物超标问题也阻碍了中药材产品进入国际市场,严重影响了中药产业的发展。针对甘肃省大宗道地药材当归、党参、甘草和黄芪,笔者综述了2009~2019年来的农药残留检测方法和和国内的标准的差距,并提出对中药中农药多组分残留检测技术研究方案,以期保证中药质量安全,促进中药产业发展。