高效液相色谱-荧光法测定水中,甲氨基阿维菌素苯甲酸盐

建立了水样中甲氨基阿维菌素苯甲酸盐(甲维盐)残留量的柱前衍生高效液相色谱测定方法.水样经乙酸乙酯提取后,运用N-甲基咪唑-乙腈(NMIM-CAN)(1+1)、三氟乙酸酸酐-乙腈(TFAA-CAN)(1+1)在避光条件下进行柱前衍生化反应,反应20min后,用高效液相色谱-荧光检测器进行测定结果表明,水中甲维盐添加浓度在0.0001-0.O1mg ·l-1范围,方法的回收率为78.4% -115.2%,变异系数为3.0%-11.3%,方法最低定量限为0.0036mg·l-1方法的灵敏度、精密度和准确度完全满足农药残留分析的要求.甲维盐在巢湖水中的残留量低于该方法的检出限,稻田水中的残留量为0.54mg·l(-1).     

水样中非离子氨与总氨量的换算公式

<正> 大量已知事实说明,各种形态氮的毒性各异。在氨氮中,离子态铵的毒性甚低,而非离子氨的生物毒性却相对很高。因此人们对水体中非离子氨的含量倍加重视。1988年6月1日开始实施的中华人民共和国国家地面水环境质量标准(GB3838—88)中已将非离子氨正式列为重要参数。由于种种限制因素,与该标准同时选配的推荐分析方法仍基于测定水体中的总氨含量。为了执行新的国家标准,必须将总氨含     

Risk assessment for the daily intake of polycyclic aromatic hydrocarbons from the ingestion of cockle （Anadara granosa） and exposure to contaminated water and sediments along the west coast of Peninsular Malaysia

The concentration of carcinogenic polycyclic aromatic hydrocarbons (c-PAHs) present in the sediment and water of Peninsular Malaysia as well as in the cockle Anadara granosa was investigated. Samples were extracted and analysed with gas chromatographymass spectrometry. The concentrations of total carcinogenic polycyclic aromatic hydrocarbons (t-PAHs) were measured between 0.80 0.04 to 162.96 14.74 ng/g wet weight (ww) in sediment, between 21.85 2.18 to 76.2 10.82 ng/L in water samples and between 3.34 0.77 to 46.85 5.50 ng/g ww in the cockle tissue. The risk assessment of probable human carcinogens in the Group B2 PAHs was calculated and assessed in accordance with the standards of the United States Environmental Protection Agency (US EPA). Case I in the toxicity assessment analysed the cancer risk to consumers of Malaysian blood cockle. Case II assessed the risk of cancer from exposure to PAHs from multiple pathways. The average cancer risk of case I and case II were found to be classifiable as unsafe according to the US EPA standard. The cancer risk due to c-PAHs acquired by the ingestion of blood cockle was (8.82 0.54) 10??6 to (2.67 0.06) 10??2, higher than the US EPA risk management criterion. The non-cancer risks associated with multiple pathways in Kuala Gula, Kuala Juru and Kuala Perlis were higher than the US EPA safe level, but the non-cancer risk for eating blood cockle was below the level of US EPA concern.     

氰化物水样测定中应注意的问题

本文分析氰化物水样测定中影响测定结果准确度的几个关键环节,并给出改进建议。     

离子色谱法同时测定水中的甲酸、乙酸、丙烯酸和氯乙酸

建立了离子色谱电导同时检测水中甲酸、乙酸、丙烯酸和氯乙酸的方法,当采用1.0mL/min、1mmol/L KOH淋洗液梯度洗脱时可达到样品中甲酸、乙酸、丙烯酸和氯乙酸分离分析的目的;乙酸、甲酸、丙烯酸和氯乙酸的线性范围分别为0.01～10.0、0.01～20.0、0.01～20.0和0.01～20.0mg/L,检出限分...     

超高效液相色谱-串联四极杆质谱分析环境水样中对苯二胺

本文建立了超高效液相色谱-串联四极杆质谱分析环境水样中对苯二胺的分析方法。方法使用C18反相柱为分离柱,柱温30℃,流速0.3ml/min,80%甲醇+20%纯水作流动相,保留时间1.92min,使用具ESI(+)源的质谱作检测器。在此条件下,水样过0.45μm滤膜后可直接进样,进样体积10μl,检出限可达0.028μg/L,在0.10～4.00μg/L范围内线性良好(R=0.9998);相对标准偏差在0.7%～4.9%之间,样品加标回收率在88.2%～118%之间,应用到实际环境水样分析中也具有令人满意的结果。该方法灵敏度高,快速简单,适用于环境水样中对苯二胺的分析。     

用蛋白磷酸酶抑制法测定水体中的微囊藻毒素类物质

建立了一种灵敏的测定水体中微囊藻毒素类物质的方法。从鱼肝脏中分离的蛋白磷酸酶２Ａ被微囊藻毒素抑制，并且抑制与毒素剂量相关，抑制模式表现为典型的Ｓ型曲线。根据末知样品存在时蛋白磷酸酶的相对活力，可由本研究得出的标准曲线及公式，计算样品中可能存在的微囊藻毒素类物质。研究表明，在一年的观测周期内，即使没有可见的水华发生，东湖及鱼池中仍有可检测出微囊藻毒素类物质。     

Formation of multiple trimethylsilyl derivatives in the derivatization of 17α-ethinylestradiol with BSTFA or MSTFA followed by gas chromatography-mass spectrometry determination

N,O-bis（trimethylsily）trifluoroacetamide （BSTFA） and N-methyl-N（trimethylsily） trifluoroacetamide （MSTFA） are common derivatization reagents used in the GC-MS analysis of estrogen steroids such as estrone （El） and 17α-ethinylestradiol （EE2）. In this study, three trimethylsilyl （TMS） steroid derivatives, mono- and di-trimethylsilyl EE2 and mono-trimethylsilyl El, were observed during the derivatization of EE2 with BSTFA or MSTFA and/or GC separation. Factors influencing the production of multiple TMS derivatives and their relative abundance were examined. It was found that both methanol and bisphenol A competed with estrogenic esteroids when reacting with silylation reagents, and thus affected the formation of TMS derivatives and their relative abundance in the derivatization products. Methanol was found to be more reactive than bisphenol A with the BSTFA reagent. None of the three solvents tested in this study could prevent the generation of multiple TMS derivatives during the derivatization of EE2 with BSTFA, followed by GC analysis. A similar result was observed using MSTFA as the derivative reagent followed by GC analysis. Thus, the suitability of BSTFA or MSTFA as the derivatization reagent for the determination of E1 and EE2 by GC-MS, under the conditions reported here, is questionable. This problem can be solved by adding trimethylsilylimidaz （TMSI） in the BSTFA reagent as recommended, and the performance of the method has been proved in this study.