固相萃取/高效液相色谱法快速测定水中痕量苯并(a)芘

采用固相萃取-高效液相色谱荧光检测法快速测定水中痕量苯并(a)芘的含量.用Silicycle硅胶萃取小柱富集苯并(a)芘,优化了固相萃取条件.结果表明固相萃取效率高,萃取时间短,苯并(a)芘在5.2～46.8μg/L的浓度范围内呈现良好的线性关系,回收率(n=4)为97.5%～104.9%,相对标准偏差为0.7%～1.8%,检出限达到0.4μg/L.该方法具有简便、快速、准确的特点,尤其适用于环境水中的痕量及超痕量苯并(a)芘的测定.     

固相萃取-高效液相色谱测定水中痕量邻苯二甲酸酯

建立了以Welchrom~?BRP固相萃取小柱,Ultimate~?AQ-C18为色谱柱,用乙腈-水为流动相梯度洗脱,紫外检测器测定水中的4种邻苯二甲酸酯。结果线性关系良好(4种邻苯二甲酸酯相关系数r为0.9965~0.9999,精密度较好(相对标准偏差为0.14%~4.54%)灵敏度较高(最低检出限为0.00001~0.00002mg/L),加标回收率为93.1%~104.9%。所建立的方法适用于生活饮用水和地表水邻苯二甲酸酯的检测。     

固相萃取-高效液相色谱法测定饮用水中的丙烯酰胺

建立了一种固相萃取-高效液相色谱法测定饮用水中的丙烯酰胺的方法。采用0.45μm的乙酸纤维滤膜过滤水样,Di KMA Proelut AC小柱(500mg/6m L)富集,Waters Symmetry C18液相色谱柱(5.0μm×4.6mm×250mm),以水和甲醇(体积比95:5)为流动相进行分离,以外标法定量分析。该方法在0.2μg/L到10.0μg/L有良好线性范围0.9993,方法的最低检出限(MLD)为0.02μg/L,加标回收率范围为82.6%~91.2%,该方法适用于饮用水中微量丙烯酰胺的分析。     

固相萃取-气相色谱-质谱法测定饮用水中毒死蜱

建立了固相萃取-气相色谱-质谱测定饮用水中毒死蜱的方法。结果表明,该方法对毒死蜱的最低检出限为0.14μg/L,线性范围为0.5～5.0 mg/L,样品平均加标回收率为75%～86%,相对标准偏差小于4.0%。该方法操作简单,灵敏度高,准确度好,重现性好,适合饮用水中痕量毒死蜱的检测。     

固相萃取气质联用测定水中痕量有机氯农药

利用C18固相萃取预处理和气质联用技术,以选择离子扫描方式对5种有机氯农药(OCPs)进行了测定.针对影响固相萃取的主要因素进行了正交试验,得到了最佳萃取条件:洗脱剂为二氯甲烷,洗脱速率为0.5 mL/min,洗脱体积为3 mL,水样流速为10 mL/min.并确定了5种OCPs的线性范围、线性相关性及最低检出限.测定结果显示,该检测方法线性相关性较好、精密度高、准确性好,适用于水中微量OCPs的测定.     

固相萃取/气相色谱/质谱法测定饮用水中毒死蜱

建立了检测饮用水中毒死蜱的固相萃取/气相色谱/质谱法,该方法对毒死蜱的测定下限可达0.000 6 mg/L,远低于国标法的0.002 mg/L。线性范围为0.5～5.0 mg/L,样品平均加标回收率在74.86%～86.14%之间,测定结果的相对标准偏差<5.4%。该方法简单、灵敏度高、准确、重现性好,可用于饮用水中痕量毒死蜱的测定。     

固相萃取-气相色谱-质谱法测定饮用水中七氯

摘要：建立了固相萃取-气相色谱-质谱法测定饮用水中七氯的方法。结果表明,该方法对七氯的最低检出限为0．054μg/L,线性范围为0．2～10．0mg／L,加标回收率为91％～96％,相对标准偏差小于2．0％。该方法操作简单,灵敏度高,准确度好,重现性好,适合饮用水中七氯的检测。     

固相萃取/毛细管气相色谱法测定水中痕量有机氯

采用固相萃取(SPE)/毛细管气相色谱法(CGC)同时测定水中的痕量环氧七氯、七氯和六六六。该方法是用Waters Oasis HLB 200 mg的6 mL小柱富集水中的环氧七氯、七氯和六六六,再用甲基叔丁基醚溶剂萃取,取其溶液上机检测。该方法对环氧七氯、七氯、α-六六六、β-六六六、γ-六六六、δ-六六六的检出限分别为0.40、0.30、0.32、0.68、0.35、0.34 ng/mL;加标回收率分别为96.53%、95.95%、104.23%、98.98%、102.88%、99.78%;测定结果的相对标准偏差(n=9)分别为1.06%、0.75%、1.22%、1.22%、0.66%、1.06%。     

原子荧光法测定饮用水中痕量铅

采用原子荧光法测定生活饮用水中铅的含量。试验结果表明，该方法的回归方程为y=37．00x＋28．25，r=0．999，在0．001～0．025mg／L范围内有良好的线性关系。采用该方法测定水中痕量铅能获得理想的结果，可在生活饮用水检测中推广运用。     

Elimination of cadmium trace contaminations from drinking water

Raw waters polluted with trace heavy metals present serious problems to the part of the Chinese water supply. One of the important contaminants is cadmium. Removal of trace amounts of heavy metals can be achieved by means of selective sorption processes. One of the possibilities is the application of weak base anion exchangers. LEWIS-base/acid interactions lead to an exclusive sorption of heavy metal cations and an equivalent amount of anions of strong acids. The respective elimination of cadmium from pure solutions and spiked natural water and the regeneration of the exhausted exchanger has been investigated. The results demonstrate a very efficient elimination. The standards for drinking water are met for a very large relative volume of treated water. In addition, even a considerable share of dissolved organic matter is adsorbed. Regeneration requires a first step with sulfuric acid to remove the metals and a second one with sodium hydroxide to neutralize the exchanger and to displace the DOC adsorbed. The heavy metals can be concentrated in a small volume which facilitates the discharge of the waste.     

Development of the revised drinking water standard for chromium

Comprehensive regulations are being developed to limit human exposure to contamination in drinking water by the United States Environmental Protection Agency (EPA) under the authority of the Safe Drinking Water Act (SDWA). These regulations are being developed in several phases and include synthetic organic chemicals, inorganic chemicals, microbiological contaminants and radionuclides. This paper addresses the fundamental concepts and approaches used by EPA in setting drinking water regulations and how EPA is using these concepts to revise the drinking water standard for chromium.     

Determination of polycyclic aromatic hydrocarbons in sea water using solid‐phase microextraction

Solid‐phase microextraction (SPME) technique with poly(dimethylsiloxane)‐coated fiber has been employed for the rapid determination of sixteen polycyclic aromatic hydrocarbons (PAHs) present in natural water. The method is solvent‐less with the analytes being adsorbed and then desorbed thermally at the injector port of a gas chromato‐graph (GC) prior to mass spectrometric (MS) analysis in selective ion monitoring (SIM) mode. The influences of the injector port temperature, desorption time and initial oven temperature on the thermal desorption of PAHs from the fiber were investigated. Then the optimum SPME conditions were applied for the qualitative and quantitative determination of PAHs in environmental samples. The recoveries of the 16 PAHs being spiked into sea water at 50 ng/mL level were 75.3%. The levels of PAHs in the Singapore coastal sea water are between 0.02–8.50 ng/mL using SPME(PDMS).     

Determination of total chromium in environmental water samples

It is often desirable to quantify both dissolved Cr(VI) and total Cr in samples accurately. Various protocols are now being utilized to quantify the amount of total chromium in natural waters and each of these has possible interferences. This study describes the shortcomings of each method when particulate iron is present in a water sample, and a more rigorous digestion protocol is tested. Data from bench studies as well as a field survey of 21 water utilities are presented. Additionally, field data from several hundred water utility samples are presented to illustrate the potential for incomplete recovery of total chromium using accepted protocols.     

铬天青法和AAS法测定水中铝的方法比对

根据第十次全国城市供水水质检测机构质量控制考核结果,比较分析了铬天青法和原子吸收法对AL的质控盲样的测定,结果表明：两种方法均符合标准要求,铬天青s法应用较广,而石墨炉原子吸收法的使用有局限。     

柱后衍生法测定饮用水中溴酸盐

采用联茴香胺离子色谱柱后衍生法测定水中溴酸盐,样品经过简单过滤或离心处理后即可直接进样分析。该方法的溴酸盐检出限为0.0005mg/L,峰面积和保留时间重现性良好,回收率为95.0%～110.0%,相对标准偏差小于3.07%。     

气相色谱-ECD法测定生活饮用水中环氧氯丙烷

用吹扫捕集仪对生活饮用水中环氧氯丙烷进行提取和浓缩,DB－5气相色谱柱进行组分分离,电子捕获检测器进行检测。当水中环氧氯丙烷质量浓度为0．1～0．7μg／L时,标准工作曲线的相关系数为0．99621,测定下限为0．1μg/L,回收率为83．8％～118％,相对标准偏差为3．0％～14％。     

对氨基二甲苯胺分光光度法测定水中余氯

建立了对氨基二甲苯胺分光光度法测定水中余氯的新方法。利用氯气在一定条件下能氧化对氨基二甲苯胺使其成为红色的氧化态形式 ,可以定量测定氯 ,实验条件如下 :最大吸收波长为5 2 0 nm ,p H控制在 2 .5～ 4.0之间 ,缓冲溶液用量为 2 ml,显色液体积为 3ml。氯浓度在 0 .1～2 .0 mg/L范围服从比尔定律。检测限 c L D为 0 .0 2 mg/L,水中常见的离子不干扰测定。该法用于自来水等样品中余氯含量的测定 ,加标回收率在 98%～ 1 0 4 %之间 ,结果准确可靠。     

催化动力光度比色法测定痕量银

ＧＢ５７４９—８５《生活饮用水卫生标准》对饮用水中银的含量做出了规定,并在ＧＢ５７５０—８５《生活饮用水标准检验法》中提出了对银的检验法即原子吸收分光光度法。该法费时、费力,操作复杂,检测成本较高且银的检出率很低。现推荐采用催化动力———光度比色法进...