超高效液相色谱-串联质谱法测定水中痕量双酚A

采用超高效液相色谱-串联质谱法测定水中痕量双酚A,水样经预处理后,以BEH C18超高效液相色谱柱分离,在质谱电喷雾离子源负离子多反应监测模式下测定.方法在0.200μg/L～10.0μg/L范围内线性良好,相关系数r为0.9992,方法检出限为0.06μg/L,空白及实际样品加标回收率为87.4% ～114%,RSD为3.6% ～7.4%.     

固相萃取-高效液相色谱法测定水中呋喃丹、甲萘威和阿特拉津

采用固相萃取-高效液相色谱(SPE - HPLC)二极管阵列检测器同时测定水中呋喃丹、甲萘威和阿特拉津,以甲醇-水为流动相,采用梯度洗脱方式,选择220 nm为检测波长,二氯甲烷为洗脱剂.呋喃丹在0.200 mg/L ～5.00 mg/L、甲萘威和阿特拉津在0.020 mg/L～5.00 mg/L范围内线性良好,检出限...     

微波消解-ICP/MS法同时测定水产品中13种元素

用硝酸-双氧水体系微波消解,以In、Sc为内标,采用电感耦合等离子体质谱法（ICP／MS）同时测定水产品中V、Cr、C0、Ni、Cu、Zn、As、Se、Cd、Sb、Ba、T1、Pb等13种元素。各元素的检出限在0．05ng／g～0．064μg／g之间,样品平行测定4次的RSD〈5％,鲢鱼样品的加标回收率在81％～117％之间。     

SPE-GC-MS/MS法测定水源水中多种有机氯EDCs

采用C 18柱固相萃取(SPE)-三重四级杆气相色谱-质谱法同时测定水中18种含有机氯的环境内分泌干扰物,方法在0.500μg/L^100μg/L范围内线性良好,方法检出限为0.04 ng/L^0.8 ng/L,空白水样的加标回收率为61.3%~108%,6次测定结果的RSD为3.8%~18.0%。将该方法用于饮用水源水监测,18种目标化合物的测定值为未检出~1.5 ng/L,平均加标回收率为71.9%~109%,平行测定结果的RSD<15%。     

固相萃取-高效液相色谱法同时测定水中12种磺酰脲类除草剂

采用固相萃取-高效液相色谱法同时测定水中12种磺酰脲类除草剂,样品经磷酸调节pH值为2后,经Watens Oasis HLB SPE柱净化浓缩,乙腈洗脱,选择检测波长为230 nm,以乙腈-水溶液(0.02%磷酸)为流动相梯度洗脱,保留时间在14 min～32 min范围内.12种磺酰脲类除草剂在0.050 mg/L～...     

固相萃取- GC/MS 法测定蔬菜水果中烯酰吗啉残留量

采用固相萃取-气相色谱／质谱联用法测定蔬菜水果中烯酰吗啉残留,优化了试验条件。方法在0.100mg／L－5.00mg／L范围内线性良好,最低检出限为0.0020mg／kg,实际样品测定的RSD≤4.6％,基质加标回收率为86.0％－96.0％。     

Preparation and utilization of molecularly imprinted polymer for chlorsulfuron extraction from water, soil, and wheat plant

A molecularly imprinted polymer (MIP) was prepared using chlorsulfuron (CS), a herbicide as a template molecule, methacrylic acid as a functional monomer, ethylene glycol dimethacrylate (EDMA) as a cross-linker, methanol and toluene as a porogen, and 2,2-azobisisobutyronitrile as an initiator. The binding behaviors of the template chlorsulfuron and its analog on MIP were evaluated by equilibrium adsorption experiments, which showed that the MIP particles had specific affinity for the template CS. Solid-phase extraction (SPE) with the chlorsulfuron molecularly imprinted polymer as an adsorbent was investigated. The optimum loading, washing, and eluting conditions for chlorsulfuron molecularly imprinted polymer solid-phase extraction (CS-MISPE) were established. The optimized CS-MISPE procedure was developed to enrich and clean up the chlorsulfuron residue in water, soils, and wheat plants. Concentrations of chlorsulfuron in the samples were analyzed by HPLC-UVD. The average recoveries of CS spiked standard at 0.05~0.2 mg L(-1) in water were 90.2~93.3%, with the relative standard deviation (RSD) being 2.0~3.9% (n=3). The average recoveries of 1.0 mL CS spiked standard at 0.1~0.5 mg L(-1) in 10 g soil were 91.1~94.7%, with the RSD being 3.1~5.6% (n=3). The average recoveries of 1.0 mL CS spiked standard at 0.1~0.5 mg L(-1) in 5 g wheat plant were 82.3~94.3%, with the RSD being 2.9~6.8% (n=3). Overall, our study provides a sensitive and cost-effective method for accurate determination of CS residues in water, soils, and plants.     

加速溶剂萃取-气相色谱/串联质谱法测定土壤中20种有机氯农药

建立了用加速溶剂萃取法（ASE）提取、气相色谱-串联质谱法分析土壤中20种有机氯农药的方法。用正己烷和丙酮（1∶1,V/V）的混合溶剂为提取剂,萃取温度100℃,压力1 500 psi,静态提取10 min,循环提取2次,提取液经石墨化碳黑固相萃取柱净化,浓缩后进行GC-MS/MS测定,外标法定量。试验结果表明,采用串联质谱多反应监测模式,降低了背景干扰,当取5 g土壤时,有机氯农药的检出限在0.1~3.0μg/kg之间,低浓度水平（8μg/kg）的基体加标回收率为70.3%~134%,相对标准偏差〈23%。测定方法背景干扰低,灵敏度高,适合土壤中20种有机氯农药残留的同时测定。     

固相萃取气相色谱法测定水中15种硝基苯类化合物

使用Oasis HLB固相萃取柱,以正己烷/丙酮混合溶剂(体积比为3∶1)为洗脱溶剂,采用毛细管柱气相色谱电子捕获检测器同时测定水中15种硝基苯类化合物,以保留时间定性,外标标准曲线法定量。硝基苯和硝基甲苯在50.0μg/L～1 000μg/L、其他硝基苯类化合物在5.00μg/L～100μg/L范围内线性良好,检出限硝基苯和硝基甲苯为0.035μg/L～0.052μg/L,其他硝基苯类化合物为0.003 5μg/L～0.005 6μg/L,加标水样平行测定的RSD为1.4%～4.0%,平均回收率为92%～100%。     

液液萃取-气相色谱/串联质谱法测定水中五氯酚及其钠盐

采用液液萃取处理水样,用气相色谱-串联质谱法测定样品中五氯酚及其钠盐,通过优化测定条件,使方法在1.00μg/L～500μg/L范围内线性良好.检出限和定量限分别为1.00μg/L和5.00μg/L,空白水样五氯酚钠3个质量浓度水平的加标回收率为89.8％～98.4％,5次平行试验测定结果的RSD为5.5％～10.7％...     

低温浓缩-气相色谱/质谱法分析固定污染源废气中的丙烯腈

建立了固定污染源废气中丙烯腈的气袋采样-低温浓缩-气相色谱/质谱分析方法。结果表明,该法在丙烯腈质量浓度16.1~4 050μg/m~3范围内具有良好的线性,相关系数R~20.999,检出限为9.54μg/m~3,回收率、日内与日间精密度均符合质控要求,能够满足废气中丙烯腈分析的要求。     

Dissipation and residue of MCPA (4-chloro-2-ethylphenoxyacetate) in wheat and soil

A rapid and simple HPLC method has been developed for the quantitation of 4-chloro-2-methylphenoxyacetic acid (MCPA) in both wheat and soil samples. Samples were extracted in acidic media and cleaned up by solid-phase extraction with C(18) cartridges before HPLC-DAD detection. The limits of detection and quantification of MCPA were 0.02 ng and 0.01 mg/kg for both wheat and soil. The mean recoveries ranged from 87.1% to 98.2%, and the RSDs ranged from 0.604% to 3.44% for the three spiked levels (0.01, 0.1, 0.5 mg/kg). The proposed method was successfully applied to the analysis of MCPA residues in wheat and soil samples from an experimental field. The dissipation half-lives in soil were calculated to be 3.22 days (Beijing) and 3.10 days (Tianjin), respectively. Direct confirmation of the analytes in real samples was achieved by gas chromatography-mass spectrometry. The results indicated that at harvest time, the residues of MCPA in wheat were well below the maximum residue levels and were safe to apply in wheat.     

小体积液液萃取-GC/MS法测定地表水中有机磷农药

采用小体积液液萃取-气相色谱/质谱联用法测定地表水中有机磷农药,以1.2 mL正己烷为萃取剂,磷酸三苯酯为内标,对8种目标化合物的富集倍数达156～436.方法在1.00 μg/L～20.0 μg/L范围内线性良好,8种有机磷农药的检出限均为0.2 μg/L,实际水样平行测定的RSD为2.1%～9.7%,平均加标回收率...     

羊角铺水源水中极微量NO -2 - N的测定

建立了自制浮选器富集、分光光度法测定羊角铺水源水中痕量亚硝酸盐氮的方法,介绍了试验的注意事项。方法在0μg／L-4．00μg／L范围内线性良好,检出限为0．0002mg／L,RSD为2．0％-4．6％,加标回收率为94．0％-108％。     

快速溶剂萃取-气相色谱/串联质谱法测定农作物中的有机氯农药

建立快速溶剂萃取,固相萃取柱净化,气相色谱/串联四极杆质谱检测分析农作物中23种有机氯农药残留的方法。以油菜为样品,加标浓度为5、10、25、50μg/kg时,平均回收率在72%~101%之间,相对标准偏差3%~14%(n=5)。8种农作物(莴笋、黄瓜、蒜苗、辣椒、油菜、茄子、玉米和水稻)加标浓度为25μg/kg时的平均回收率在71%~113%之间,相对标准偏差3%~16%(n=5)。方法检出限0.75~1.76μg/kg之间。     

Occurrence of antibiotic resistance and characterization of resistance genes and integrons in Enterobacteriaceae isolated from integrated fish farms in South China

Antibiotics are still widely applied in animal husbandry to prevent diseases and used as feed additives to promote animal growth. This could result in antibiotic resistance to bacteria and antibiotic residues in animals. In this paper, Enterobacteriaceae isolated from four integrated fish farms in Zhongshan, South China were tested for antibiotic resistance, tetracycline resistance genes, sulfonamide resistance genes, and class 1 integrons. The Kirby-Bauer disk diffusion method and polymerase chain reaction (PCR) assays were carried out to test antibiotic susceptibility and resistance genes, respectively. Relatively high antibiotic resistance frequencies were found, especially for ampicillin (80%), tetracycline (52%), and trimethoprim (50%). Out of 203 Enterobacteriaceae isolates, 98.5% were resistant to one or more antibiotics tested. Multiple antibiotic resistance (MAR) was found highest in animal manures with a MAR index of 0.56. Tetracycline resistance genes (tet(A), tet(C)) and sulfonamide resistance genes (sul2) were detected in more than 50% of the isolates. The intI1 gene was found in 170 isolates (83.7%). Both classic and non-classic class 1 integrons were found. Four genes, aadA5, aadA22, dfr2, and dfrA17, were detected. To our knowledge, this is the first report for molecular characterization of antibiotic resistance genes in Enterobacteriaceae isolated from integrated fish farms in China and the first time that gene cassette array dfrA17-aadA5 has been detected in such fish farms. Results of this study indicated that fish farms may be a reservoir of highly diverse and abundant antibiotic resistant genes and gene cassettes. Integrons may play a key role in multiple antibiotic resistances posing potential health risks to the general public and aquaculture.     

Dissipation studies of fentrazamide (YRC-2388) in soil under anaerobic condition

Dissipation of fentrazamide in soil and water under flooded (anaerobic) conditions was studied. Fentrazamide was applied to soil at 100 g ha(-1). Soil was extracted with 0.1 N HCl?:?acetone (1?:?1 v/v) followed by partition and cleanup with silica SPE. Separation was achieved in an ODS-II column with a mobile phase of acetonitrile?:?water (70?:?30 v/v) and detection at 214 nm. Recovery of fentrazamide varied from 75.2-90.4% and 89.9-97.8% in soil and water, respectively. Fentrazamide dissipated rapidly and fentrazamide residues were not detected after 100 and 35 days of application in soil and water, respectively. Half life in soil and water was 9.06 and 3.66 days, respectively. Dissipation followed monophasic first order kinetics pattern. No fentrazamide was detected in soil, rice grain and rice straw at harvest of crop. Calibration curves for quantification were linear and relative standard deviation (RSD) was 1.78%. LOD for instrument was 0.002 μg mL(-1) and LOQ for methods were 0.005 μg g(-1) for soil and water.     

Evaluation of trace heavy metal levels of some fish species sold at retail in Kayseri, Turkey

Cd, Ni, Cr, Zn, Cu and Pb concentrations of muscle tissue of 61 fish samples belonging to six fish species (Sparus auratus, Pomatomus saltatrix, Sarda sarda, Engraulis encrasicholus, Sander lucioperca, Scomber scombrus) retailed in Kayseri, Turkey were determined by flame atomic absorption spectrometry after wet digestion. Cd concentrations of at least 31 fish samples (50.8%) and Pb concentrations of at least six fish samples (9.8%) exceeded the corresponding Turkish permissible limit of 0.05 and 0.2 mg kg(-1) respectively whereas Zn concentrations of 11 fish samples (18%) exceeded the Turkish Food Codex limits of 50 mg kg(-1) for Zn. Cu concentrations of all fish species analyzed (100%) were below the corresponding Turkish legislations of 20 mg kg(-1). No limits were established concerning Ni and Cr concentrations in fish by the Turkish governmental authorities.     

Dissipation of flubendiamide in/on Brinjal (Solanum melongena) fruits

A field experiment was conducted at Anand Agricultural University, Anand during Sept-Dec, 2009 to study the rate of degradation of flubendiamide in/on brinjal fruits following foliar application of Fame 480 SC at 90 (standard dose) and 180 (double dose) g a.i. ha(?-1). The residues estimated using HPLC revealed persistence of flubendiamide in/on brinjal till 3rd and 7th day after the last spray at standard and double dose, respectively. The residues of flubendiamamde were reported as parent compound, and no desiodo metabolite was detected. The initial deposits of 0.17 and 0.42 μg g(?-1) in/on brinjal fruits reached below determination level of 0.05 μg g(?-1) on the 5th and 10th day at standard and double dose, respectively. The half life of flubendiamide on brinjal fruits ranged from 2.68 to 2.55 days. Soil samples analyzed on the 15th day after the last spray revealed residues at below determination level (0.05 μg g(?-1)) at either dose of application.     

加速溶剂萃取-固相萃取小柱净化-气相色谱法测定土壤中有机磷农药

建立了加速溶剂萃取-固相萃取小柱净化-气相色谱法测定土壤中12种有机磷农药的方法。推荐了12种有机磷农药快速分离的色谱条件。采用加速溶剂萃取技术实现了对土壤中有机磷农药残留的提取,选取最佳条件参数,减少了组分的损失,提取回收率达88%～108%。选择不同填料的SPE小柱和洗脱溶剂形成3种方案法进行净化实验,结果表明,方案2采用混合溶剂(正己烷、丙酮、二氯甲烷体积比为1∶1∶1)洗脱上样后的硅胶SPE小柱的净化效果好,回收率为91%～121%。方法检出限为0.000 1～0.000 2 mg/kg,石英砂基体和实际污染土壤样品加标回收率为62%～112%,相对标准偏差为0.7%～8.6%。该方法操作简便,快捷,灵敏度高,检出限低,试剂用量少,准确度和精密度符合质量控制要求。