广州郊区菜地、果园、稻田有机氯农药残留特征初步研究

目的 研究广州郊区菜地、果园、稻田土壤中有机氯农药残留特征.方法 于2008年8月采集广州市白云、从化、增城、番禺、南沙5个区域的菜地、果园、稻田0～20cm表层土壤样品.对白云和番禺两个采样点增加采集20～40 cm和40～60 cm两个剖面的土壤样品,采用气相色谱-电子捕获检测器法(GC-ECD)检测17种有机氯农药.结果 表层土壤17种有机氯农药检出率为90.59%,其残留量范围为4.19～39.89 ng/g;剖面土壤17种有机氯农药检出率为76.70%,其残留量范围为2.35～91.26ng/g.有机氯农药(OCPs)主要残留物是六六六类(HCHs)和滴滴涕类(DDTs).结论 有机氯农药检出率较高,白云和番禺的菜地20～40 cm剖面土壤OCPs超标,对土壤环境有一定危害.

Abstract：

Objective To analyze the characteristics of of organochlorine pesticides (OCPs) residues in the soil of the suburbs of Guangzhou.Methods In Baiyun,Conghua,Zengcheng,Panyu,Nansha,surface soil(0-20 cm)samples of vegetable fields,orchard and paddy soil were collected,soil profile(20-40cm,40-60cm)of Baiyun and Panyu were also collected,in Aug,2008.Gas chromatography-electron capture detector method(GC-ECD)was used to determine 17 kinds of organochlorine pesticides.Results The detection rate of 17 kinds of organochlorine pesticides was 90.59%in topsoil,the residue level was4.19-39.89 ng/g,and the detection rate in profiles soil was 76.70%,the residue level was 2.35-91.26 ng/g.OCPs residues were mainly HCHs and DDTs.Conclusion Detection rate of organochlorine pesticides is high in soil in the investigated soil and in the 20-40 cm profiles of Baiyun and Panyu,the level of OCPs exceeds the related standard limit,which may have adverse effects on soil environment.     

小麦玉米中残留灭多威的提取净化及气相色谱测定方法研究

本文用气相色谱法测定小麦、玉米中灭多威残留量。灭多威经乙酸乙酯提取后，用石油醚萃取净化，用氯仿萃取分离，用火焰光度检测的气相色谱法测定。灭多威的检测限为０．１ｎｇ，在小麦、玉米中的最低检出浓度为０．０２５ｍｇ／ｋｇ，加标浓度为０．６０￣２．５０ｍｇ／ｋｇ时，平均回收率为９５．５％￣１０２．３％，其变异系数小于５％。本法操作简便、快速，准确度高，精密度好。     

气相色谱法测定栝楼桂枝汤纯化物中大孔树脂有机残留物

目的 建立栝楼桂枝汤纯化物中4种大孔树脂有机残留物的检测方法.方法 采用毛细管气相色谱法,测定栝楼桂枝汤纯化物中正己烷、苯、甲苯、二甲苯4种大孔树脂有机残留物的含量.结果 4种成分在相应线性范围内线性关系良好,r=0.9998~0.9999,平均回收率符合要求,各组分均未检出符合要求.HT5"H结论 该方法简便可行,精密度好,结果可靠,适用于栝楼桂枝汤纯化物中大孔树脂有机残留物的检测.     

Bromoxynil residues and dissipation rates in maize crops and soil

A residue analytical method for the determination of bromoxynil in soil and maize was developed using high performance liquid chromatography with diode-array detector (HPLC-DAD) and high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). The residual level and dissipation rate of bromoxynil in the soil and maize crops were determined using the established method. The mean half-life of bromoxynil in soil was 4.12 days with a dissipation rate of 91.25% over 21 days. The mean half-life in maize seedling was 1.14 days with a dissipation rate of 97.79% over 7 days. The final residues of bromoxynil were undetectable in maize grain, maize stem and soil at the harvest time, suggesting that residual levels of bromoxynil in maize plants are safe to humans and animals as well as to the environment.     

Dissipation of Quinalphos in Kinnow Mandarin Fruits under Subtropical Conditions of Punjab,India

Quinalphos residues were studied separately in the pulp and rind of kinnow mandarin fruits by following a standardized methodology and estimated on gas liquid chromatograph (GC) by employing nitrogen phosphorus detector. Following application of quanilphos (Ekalux 25EC) at 10.0 and 20.0 mL per tree (per 5 L of water) on kinnow mandarin fruits at both these dosages were found to be 0.05 and 0.16 mg/kg, respectively. These initial deposits were found to be less than its maximum residue limit (MRL) of 0.25 mg/kg. The corresponding values in the rind were found to be 0.65 and 1.64 mg/kg, respectively. These residue levels in the rind dissipated below the MRL in 5 and 15 days, respectively. The half-life value for quanilphos in the rind at single and double dosages were found to be 3.2 and 4.0 days, respectively. Low dissipation rate of quanilphos in the rind may be attributed to the fibrous nature of the peel where the insecticide can be adsorbed, high moisture content and oil based nature of the rind. The results clearly show that quanilphos does not penetrate into the pulp of the kinnow mandarin and the fruit is safe for consumption even after one day of the application at both these dosages.     

正交实验法优选枇杷叶药渣中乌索酸提取工艺

目的确定枇杷叶药渣中乌索酸的最佳超声提取工艺条件。方法采用正交设计L9(34)方法,考察乙醇浓度、料液比、超声时间和提取次数对乌索酸提取率的影响,用高效液相色谱法测定含量,并与常规提取法进行了对比。结果所考察的因素对枇杷叶药渣中乌索酸提取的影响程度为:乙醇浓度>提取次数>料液比>超声时间;超声提取的最佳条件为:A3B1C1D2。结论与常规的提取方法相比,超声提取具有提取时间短、操作简单、提取率高、无需加热等优点。     

SPE-HPLC法同时测定水产品中四种抗生素残留的研究

目的 :为快速、简便、灵敏的检测水产品中土霉素、四环素、金霉素、氯霉素残留 ,建立了固相萃取(SPE) -高效液相色谱 (HPLC)分析法。方法 :样品高氯酸沉淀蛋白质 ,超声波提取 ,固相萃取 ,高效液相色谱法同时测定 4种抗生素。固相萃取小柱为ZORBAXSPEC18Cart,洗脱液为 5 0 %甲醇水 ;色谱柱为SUPELCODiscoveryC185 μm 2 5 0× 4 . 6mm ,流动相为 0 . 0 1mol/L　磷酸二氢钠 +0 . 0 0 1mol/L　EDTA :甲醇 =6 0∶4 0 (V/V ,pH =2. 0 ) ,流速为 0 .8ml/min ,检测波长为 2 6 8nm。结果 :本方法的最低检出浓度分别为 :土霉素 (0. 0 18mg/kg)、四环素 (0 . 0 2 5mg/kg)、金霉素(0 .0 4 3mg/kg)、氯霉素 (0 . 0 10mg/kg)、标准曲线线性良好 ,其回归方程及相关系数r分别为土霉素 :y =5 6 . 32 15x -0 . 90 0 4 ,r=0 .9999;四环素 :y =4 2 .8345x - 1 .14 84 ,r=0 .9999;金霉素 :y =2 3 0 0 97x - 0 . 96 30 ,r =0 . 9999;氯霉素 :y=38 .8332x+0 . 16 5 5 ,r=0 . 9999,回收率在 93%～ 10 1%之间 ,相对标准偏差小于 1 .9%。结论 :以超声波萃取 ,经固相柱净化、用二极管阵列检测器是一种快速、灵敏、简便的测定水产品中抗生素残留的高效液相色谱方法。     

无花果残渣中抗肿瘤成分的超临界CO2萃取和抑瘤试验

目的:研究无花果残渣中抗肿瘤功效成分的超临界CO₂萃取技术及萃取物的体内外抗肿瘤效果。方法:采用MTT法检测萃取物质的体外抗肿瘤活性,研究残渣中抗肿瘤功效成分的最佳萃取条件;采用MTT法研究萃取物质对U937细胞、95D细胞和AGS细胞3株肿瘤细胞株的体外抑制作用;以小鼠移植性肝癌Heps为对象,研究萃取物对体内肿瘤的抑制作用。结果:超临界CO₂提取的最佳工艺条件为:粉碎度100目,萃取压强30MPa,萃取温度45℃,萃取时间6h,气体流量12L.h^-1,萃取得率为25.3g.kg^-1,得到的萃取物在体外对U937细胞、95D细胞和AGS细胞具有一定的抑制作用,IC₅₀分别为70.125,127.957,116.000μg.mL^-1。萃取物对小鼠移植性肝癌Heps在25mg.kg^-1的剂量时抑瘤率为49.3%。结论:本萃取工艺合理、稳定。可以为无花果残渣和无花果中抗肿瘤功效成分的提取提供参考。     

肠衣中醋酸甲羟孕酮残留ELISA检测方法的应用

[目的]为醋酸甲羟孕酮残留检测提供一种快速、灵敏的分析方法。[方法]利用MPA-BSA免疫新西兰大耳白兔获得抗醋酸甲羟孕酮的多克隆抗体。建立了MPA的ciELsIA方法，并对肠衣样品进行了样品添加回收试验。[结果]MPA浓度在0.4-50ng/ml范围内具有良好的线性关系，线性方程为y=6.29-1.7χ，r^2=0．9995，IC50为3.7ng／ml，向样品中分别添加1、2、5ng／g 3个浓度水平的MPA标准品，回收率为85％-110％之间，变异系数为7．1％～9．9％，最低检测限0．8ng／g。药物交叉反应性试验符合要求。[结论]该ELSIA方法快速、灵敏、方便，满足了醋酸甲羟孕酮残留检测的要求。     

酶联免疫分析法测定水产品中磺胺二甲基嘧啶残留量

目的:建立测定水产品中磺胺二甲基嘧啶残留量的ELISA分析法。方法:对不同样品采用不同的前处理方法,用ELISA方法进行检测。结果:方法检测低限为:10μg/kg;在10μg/kg和20μg/kg两个添加水平,样品加标平均回收率分别为74.0%~100.0%和82.0%~102.0%;重复性试验:RSD分别为3.5%~4.9%和4.5%~5.8%;重现性试验:RSD分别为5.4%和4.9%。结论:本方法灵敏度、准确度和精密度均符合残留分析质量控制的要求,适用于水产品中磺胺二甲基嘧啶残留量的快速检测。