异丙醇增感电感耦合等离子体质谱法直接测定土壤和沉积物中硒

提出了沸水浴混合酸法消解,以异丙醇为增感剂,电感耦合等离子体质谱直接测定土壤和沉积物中硒的方法。实验表明2mol/L硝酸-4mol/L盐酸混酸能有效溶出土壤和沉积物中各种形态的硒。相对于1%硝酸基体,4%(V/V)异丙醇基体中硒的ICP-MS响应值提高了12.1倍;而且4%(V/V)异丙醇基体可有效抑制硒的质谱干扰。ICP发射功率和雾化气流速是影响异丙醇在ICP-MS测定过程增敏效应的主要因素。以78硒为测定同位素,方法检出限为0.005mg/kg,实际样品测定精密度均小于5%。用于测定土壤和沉积物国家标准样品并对其消解液进行加标回收实验,结果令人满意。     

L-半胱氨酸预还原-氢化物发生-原子荧光光谱法测定水中的锑

在稀H：sO。介质中,以L-半胱氨酸作预还原剂,用氢化物发生-原子荧光光谱法测定水中的锑。L-半胱氨酸的存在,改善了氢化物发生条件和增敏光谱测定信号,当在低酸度下发生锑的氢化物时,过渡金属离子的干扰显著地得到了抑制,灵敏度提高,方法的检出限为0．13μg／L,回收率为92．5％～106．5％。     

Releases of phosphate fertilizer industry in the surrounding environment: Investigation on heavy metals and polomum-210 in soil

Distribution of Cu,Zn,Pb,Cr,Ni,Mn concentrations and the activity of polonium-210 in the surrounding area of a phosphate fertilizer industry located on the eastern coast of the Mediterranean Sea has been determined.Nineteen sampling sites were distributed around the industrial zone on a surface area of about 100,000 m2.Atomic absorption spectroscopy and Alpha spectroscopy were used to quantify the heavy elements and polonium-210,respectively.Investigation on a particle scale was conducted by TEM and SEM coupled to EDX and X-ray cartography to determine the nature of heavy elements carders and their distribution.Heavy elements were mainly concentrated inside the particle size fraction ＜ 50μm.Their levels decreased with distance increasing from the industry.According to the reference soil,enrichment factors were about 10,15,32 and 100 times for Zn,Pb,Cu,and Cr,respectively inside the particle size fraction ＜ 50 μm on the closest sites to the industry.The main contaminant sources were transport and storage of row materials and the free release of phosphogypsum waste.Heavy elements were entrapped inside agglomerates of sulfates,phosphates and iron oxihydroxides in a diffused shape.Polonium-210 with an enrichment factor of about 56,showed the same behavior of the spatial distribution of the trace elements.     

Improved preparation and identification of aristolochic acid-DNA adducts by solid-phase extraction with liquid chromatography-tandem mass spectrometry

Aristolochic acid (AA) is a known nephrotoxin and potential carcinogen, which can form covalent DNA adducts after metabolic activation in vivo and in vitro. A simple method for preparation and characterization of aristolochic acid-DNA adducts was developed. Four AA-adducts were synthesized by a direct reaction of AAI/AAII with 2’-deoxynucleosides. The reaction mixture was first cleaned-up and pre-concentrated using solid phase extraction (SPE), and further purified by a reversed-phase high performance liquid chromatography (HPLC). By the application of developed SPE procedure, matrices and byproducts in reaction mixture could be greatly reduced and adducts of high purity (more than 94% as indicated by HPLC) were obtained. The purified AA-DNA adducts were identified and characterized with liquid-electrospray ionization-quadrupole-time of flight-mass spectrometry (LC-ESI-Q-TOF-MS/MS) and LC-Diode array detector-fluorescence (LC-DAD-FL) analysis. This work provides a robust tool for possible large-scale preparation of AA-DNA adduct standards, which can promote the further studies on carcinogenic and mutagenic mechanism of aristolochic acids.     

氢化物发生原子荧光光度法分析空气中铅

为提高空气中铅分析的灵敏度,采用氢化物发生原子荧光分析方法进行空气中铅的测量.分别采用微波加热方法和湿式消解法对样 品进行了预处理,对两种消解方法进行了比较,并探讨了样品前处理过程对分析的影响;对影响氢化物发生效率的各种实验条件,包括增敏剂、酸介质及氢化物发生体系中各物质浓度等,以及原子荧光分析仪器的条件参数进行了优化...     

自动消解仪-火焰原子吸收分光光度法测定土壤中的总铬

本文研究了自动消解仪在土壤前处理时的条件,成功地将该方法应用于火焰原子吸收分光光度法测定标准样品及土壤样品中的总铬。     

吹扫捕集-气相色谱-质谱法测定水中环氧氯丙烷的不确定度评定

依照《测量不确定度评定与表示》,对吹扫捕集-气相色谱-质谱法测定水中环氧氯丙烷的结果进行不确定度评定。通过评定可知标准曲线配制过程所引入的相对不确定度最大,吹扫捕集-气相色谱-质谱法测定模拟水样中环氧氯丙烷结果为（78±21）μg/L。     

海洋生物样品中多溴联苯醚和多溴联苯的分析研究

将气相色谱-负离子化学源／质谱法(GC-NCI/MS)应用于分析海洋生物中五种多溴联苯醚(PBDEs)和五种多溴联苯(PBBs)残留.样品以正己烷／丙酮(1:l,v/v)作为提取剂,采用超声萃取法,提取液经酸性硅胶和中性硅胶层析柱净化和正己烷洗脱后,以PCB-103为内标物和GC-NCI/M的选择离子监测方式(SIM)...     

同位素稀释-液相色谱-串联质谱法同时测定养殖水体中23种镇静剂

建立了同位素稀释-液相色谱-串联质谱法（LC-MS/MS）同时测定养殖水体中23种镇静剂残留的方法。样品经0.45 μm滤膜过滤后,用Oasis HLB固相萃取柱净化,浓缩后用50%的甲醇水定容。以1%甲酸水溶液和乙腈为流动相,采用Agilent InfiniityLab Poroshell 120 SB-C18色谱柱分离后,在多反应监测模式下测定,内标法定量。结果表明,23种镇静剂在0.5～100ng/L质量浓度范围内线性关系良好（r>0.99）,检出限和定量限分别为0.1~0.3和0.4 ~1.0 ng/L。加标回收率为73.5%~117.6%,相对标准偏差（RSD）为1.1%~9.9%。该方法前处理简单,净化效果较好,灵敏度较高,适用于池塘养殖水体中23种镇静剂类药物残留的快速检测。     

微波辅助提取-氢化物发生原子荧光光谱法测定土壤中As（Ⅲ）和As（Ⅴ）

建立了微波辅助提取,采用氢化物发生原子荧光光谱法不进行价态分离,直接测定土壤中As（Ⅲ）和As（Ⅴ）的方法。通过加入抗坏血酸作为抗氧化剂,以磷酸溶液、L-半胱氨酸分别为提取剂和还原剂,在不还原与还原两种情况下分别进行测量,根据荧光强度与As（Ⅲ）和As（Ⅴ）的质量浓度关系方程式计算提取液中它们的质量浓度。对实验条件进行优化后,As（Ⅲ）、As（Ⅴ）的方法检出限均可达到0.05μg.g-1,实验精密度（RSD,n=11）分别为1.3%和2.1%,样品加标平均回收率分别为As（Ⅲ）为93.2%~110.0%,As（Ⅴ）为92.6%~104.0%。该方法不需要高效液相色谱等大型设备、简单可靠、易于操作、分析速度快、精密度高,具有在各分析测试实验室推广应用价值。方法已用于实际土壤样品中不同价态无机砷质量分数的测定。