固体进样直接测定法测定铜精矿中汞

建立了固体进样直接测定法测定铜精矿中汞含量的方法。铜精矿样品在测汞仪的分解炉中经300℃干燥和750℃高温热分解后,汞被催化分解为汞原子,于850℃齐化成金汞齐。汞蒸气被氧气流带入单波长光学吸收池,在波长253.7 nm处测量汞的吸光度,采用标准曲线法计算汞量。方法的线性范围分别为0~1.00,0~100μg/mL,线性相关系数为0.9999,检出限分别为0.10,0.04 ng/g。5个汞含量不同的铜精矿样品测定结果的相对标准偏差为2.14%~4.35%(n=11),样品加标回收率为92.00%~104.02%。采用该方法分别对2个铜精矿样品和铜精矿国际标准物质进行测定,测定结果与标准分析方法测定值和标准物质标示值基本一致。该方法简便、快速、准确,可以作为标准方法推广使用。     

冷蒸气发生-原子荧光法测定海水中超痕量汞

采用具有高稳定度汞灯漂移校准系统的原子荧光光度计作为检测器，在对原子荧光光度计的仪器和检测条件进行优化后，建立了以硫酸-过硫酸钾消解海水样品，冷蒸气发生-原子荧光法测定海水中超痕量汞的方法。在载气、辅助气、屏蔽气流量分别为200、100、500 mL/min，还原剂硼氢化钾浓度为0.05%（质量分数），载流为含有0.05%重铬酸钾（质量分数）的2%硫酸溶液（体积分数）的最佳分析条件下，汞的线性范围为0～0.25μg/L，相关系数为0.999 7，检出限为0.000 7μg/L。对汞质量浓度为（1.00±0.06）μg/L的海水标准物质进行6次平行测定，汞的相对标准偏差为2.95%，相对误差为-0.10%。对两种低汞含量海水样品进行6次平行测定，汞的质量浓度测定值分别为0.012、0.016μg/L，相对标准偏差分别为6.80%、4.70%，加标海水样品汞的回收率为86.67%～100%。该方法检测海水中的超痕量汞具有较高的准确性和稳定性。     

氧瓶燃烧—冷原子吸收法测煤样中痕量汞

采用氧瓶燃烧－针筒注射－冷原子吸收法测煤样中痕量汞，并对测定条件进行研究。方法简便、快速、干扰少，汞含量在０￣１０．０ｎｇ／５０ｍｌ时遵守比耳定律。用于样品的测定，结果令人满意。     

悬浮液-氢化物原子荧光法测定疏浚倾废物中汞

1引言 对于疏浚物样品中汞的前处理，通常采用湿法消化法。但该方法操作繁琐，消解时间长，容易引起操作玷污和待测成分损失，而且试剂消耗量大，产生的酸气危害操作人员的身体健康。近年倍受关注的悬浮液进样技术则克服了传统酸消化的不足，具有适合固体分析的优越性以及相对溶液来说所特有的方便性，它减少或避免污染和损失，节省时间。该技术在测定食品、环境和地质样品中痕量元素应用广泛，但尚未见悬浮液原子荧光光谱法应用于疏浚倾废物样品中汞分析的报道。本实验提出一种悬浮液进样技术与原子荧光光谱法相结合测定疏浚倾废物样品中痕量汞的分析方法。研究了悬浮液的粒度、酸介质以及酸度和悬浮液浓度等因素的影响。方法简便，快速，测定结果准确可靠。     

氢化物-原子吸收光谱仪测定食品中的汞

本文研究了采用氢化物原子吸收光谱法测定食品中痕量汞,通过采用氢化物发生器,选择合适浓度的载流和硼氢化钾,获得了较为满意的分析结果。采用此方法测定汞含量在5-20μg/kg的食品标准样品,测试结果相对标准偏差2.21-3.65%,回收率84.9-97.5%,检出限0.2 μg/L,完全满足食品行业汞元素痕量检测要求,操作简便、快速。     

大体积进样-原子荧光光谱法 测定海水中痕量汞

海洋中的汞在生物体内会转化为毒性高的甲基汞,影响海洋生物体的健康,进而威胁到人类的健康。同时,由于汞元素的记忆效应,使其会残留在光谱仪器设备中,影响仪器空白值和参数设置,以及测量结果的准确性和可靠性。海水中的汞含量处于超痕量水平,其分析检测是目前的难点之一。本文研究了一种大体积进样-原子荧光光谱法测定海水中痕量汞的方法,考察了不同前处理方式、酸的种类、还原剂浓度和原子化方式对检测的影响,并针对性利用烷基汞验证了不同条件下的检测结果,对方法进行了改进和验证,并对不同海域的海水进行了检测。实验结果表明：采用大体积进样,用盐酸代替硫酸,检测低浓度样品结果更准确;用甲基汞、乙基汞加标和低浓度还原剂对比验证过硫酸钾消解前处理时室温消化24h和加热煮沸1min两种消解方式,两种方式的加标回收率均接近100%;测量不同海域海水样品平行性好,结果准确,该方法对不同海域海水具有普遍适用性。     

高压溶样冷原子荧光法测定中药中痕量汞

采用高压溶样的消解方式,应用YYG-2型原子荧光分光光度计,建立了中药中痕量汞的测定方法。试验了氯化亚锡浓度、负高压、载气流量、还原时间等的影响。在试验条件下,检出限为0.03μg.L-1,回收率为94%~112%,国标物质桃叶验证结果与推荐值一致,用于样品中痕量汞的测定,结果满意。     

氢化物发生-原子吸收光谱法测定食品中的汞

研究了采用氢化物发生-原子吸收光谱法测定食品中痕量汞的方法,通过采用氢化物发生器,选择合适浓度的载流和硼氢化钾,获得了较为满意的分析结果。在测定汞含量5～20μg/kg的食品标准样品时,测试结果相对标准偏差RSD为2.2%～3.7%,回收率为84.9%～97.5%,检出限为0.2μg/L,完全满足食品行业汞元素痕量检测要求,操作简便、快速。     

汞的形态分析研究：Ⅱ.固相萃取预富集—液相色谱分离测定不同形态…

本文报道了固相萃取预富集处理样品继以液相色谱分离测定不同形态痕量有机汞的方法。二乙基二硫代氨基甲酸钠作络合剂及甲醇作洗脱液的预富集系统能在线富集甲基汞、乙基汞和苯基汞。     

超声辅助浊点萃取-原子荧光光谱法测定水中痕量汞

为了适应水中痕量汞的分析要求,降低汞的检出限,建立了一种超声辅助浊点萃取预富集联合原子荧光光谱法测定水样中痕量汞的方法。该方法采用硫代米氏酮为络合剂,以非离子型表面活性剂Triton X-114为萃取剂,将水样中的痕量汞富集于表面活性剂相。在原子荧光光谱分析前,加入磷酸三丁酯作为消泡剂,用5%盐酸溶液定容,富集倍数可以达到10倍。优化萃取体系pH、络合剂用量、萃取剂用量、超声平衡条件等浊点萃取的条件,在最优条件下,该方法检出限为0.003 μg/L,相对标准偏差为4.2%~8.6%,加标回收率为85%~106%。结果表明,超声辅助浊点萃取-原子荧光法能够适用于对地表水、自来水等清洁水样中痕量汞的分析,且具有更低的检出限,良好的准确度和精密度,能够适应于更高的样品分析要求。     

一次消解土壤样品测定汞、砷和硒

建立了测定土壤中3种挥发性元素(汞、砷、硒)的一次消解方法,确定以程序控温石墨自动消解仪+王水-氢氟酸-硼酸络合敞开体系为最佳消解体系,采用氢化物发生-原子荧光光谱法(HG-AFS)分别测定同一消解液中汞、砷、硒的含量.采用国家标物中心有证标准物质土壤环境样品GSS-1~GSS-8进行了方法验证,结果均符合标准偏差的允许范围.此消解方法相比于现行标准方法,避免了针对各元素的分次处理,简化了消解步骤,节省了前处理时间,减少了试剂消耗,提高了实验效率,适用性广、灵敏度高、检出限低,尤其适合批量样品的微量/痕量元素分析,可作为一种大规模土壤样品中重金属污染监测和治理的快捷方法.     

Optimization of microwave digestion for mercury determination in marine biological samples by cold vapour atomic absorption spectrometry

Optimization of acid digestion method for mercury determination in marine biological samples (dolphin liver, fish and mussel tissues) using a closed vessel microwave sample preparation is presented. Five digestion procedures with different acid mixtures were investigated: the best results were obtained when the microwave-assisted digestion was based on sample dissolution with HNO3-H2SO4-K2Cr2O7 mixture. A comparison between microwave digestion and conventional reflux digestion shows there are considerable losses of mercury in the open digestion system. The microwave digestion method has been tested satisfactorily using two certified reference materials. Analytical results show a good agreement with certified values. The microwave digestion proved to be a reliable and rapid method for decomposition of biological samples in mercury determination.     

活性炭富集-电热塞曼原子吸收光谱法测定水中痕量的汞

建立了一种水中痕量汞的测定方法。通过活性炭定量吸附水中痕量汞,采用电热塞曼原子吸收光谱法测定活性炭富集的汞。与目前水中总汞测定方法相比,本方法避免了消解等步骤,减少了汞污染和汞损失,操作更加简单。考察了活性炭粒度、酸处理方法、酸介质和富集时间对富集效率的影响,以及热解温度和干扰离子对方法测定结果的影响。通过空白活性炭加标、空白溶液加标和环境水样加标3种方法制作标准曲线,三者的相关系数达0.9999,经统计检验,3条标准曲线的斜率无差异,表明了在此实验条件下环境水样中的共存物不干扰汞的测定,同时也表明可直接用空白活性炭加标的方法进行标准曲线的绘制。采用本方法对含5和50 ng/L汞的水样进行测定,其相对标准偏差分别为7.2%和4.2%(n=11)。本方法测定下限达到1.2 ng/L。地表水和自来水样中添加10 ng/L汞的加标回收率在92.0%~103.0%之间。用 ICP-MS作对照,二者分析结果相符合,相对误差在2.9%~ 3.4%之间,表明本方法准确可靠、精密度好。     

Trace mercury analysis in biological material: use of 203Hg-labelled methylmercury chloride for in vivo labelling of fish to study the efficacy of various wet ashing procedures

Several wet ashing techniques for trace mercury analysis by cold vapour atomic absorption have been evaluated with radiotracer mercury, and in particular fish labelled in vivo with ²⁰³Hg-tagged methylmercury chloride. Partial digestion methods suffer from strong matrix effects; these include incomplete extraction from the sample, hold-back of mercury in the extraction solution during the reduction/aeration step, and alteration of the aeration release pattern so as to cause low results if measurement is based on peak height. A complete digestion method is outlined; this gives good results and is tentatively recommended pending further tests with other types of biological samples.     

Determination of total and methyl mercury in human permanent healthy teeth by electrothermal atomic absorption spectrometry after extraction in organic phase

A simple and sensitive method has been developed for determination of inorganic and methyl mercury in biological samples by ETAAS. For determination of methyl mercury; it was transferred to toluene phase by acid leaching extraction method. For total mercury after digestion of samples; it was extracted to toluene phase by means of the chelating agent diethyldithiocarbamate. Formation of complex between MeHg and diethyldithiocarbamate enhance the MeHg signal and increases the reproducibility. Furthermore, Pd-DDC was used as modifier for both mercury and methyl mercury determinations. The optimization performance was independently carried out by modifying the parameters such as temperature of mineralization, atomization and gas flow rate for methylmercury and inorganic mercury in ETAAS. The limits of detection were 0.15 and 0.12 μg g⁻¹ for methyl mercury and total mercury, respectively. The repeatability of the measurements of whole procedure were 15.8% for methyl mercury and 16.9% for total mercury determination. The accuracy of the method has been investigated by means of spiking different amounts of methylmercury and inorganic mercury to the samples. The recoveries were found within the range of 88-95% for methyl mercury and 85-92% for total mercury. For determination of total mercury, the method was validated by CVAAS. The obtained results by the present procedure were in good agreement with those of the CVAAS. The proposed method was applied for 30 human permanent healthy teeth (without filling) which significant positive correlations were found among number of amalgam filling and total mercury and MeHg.     

Low pressure ring discharge emission spectroscopy in the assaying of mercury ultra-low traces

The possibility of using low pressure ring discharge emission spectroscopy in the determination of mercury is shown. The investigations were carried out using several different water and air samples and involved different methods of isolating the mercury from the samples. It is shown that this method is useful for mercury determinations at ultra-low trace concentrations.     

Some Aspects on Preconcentration for Neutron Activation Analysis

A preconcentration method incorporated with neutron activation analysis was developed for the accurate determination of trace metals in biological and environmental samples. Bismuth diethyldithiocarbamate, thallium diethyldithiocarbarnate, and ammonium pyrrolidinedithiocarbamate were used as the preconcentration agents for three groups of metals. Trace metals were enriched and interfering elements such as Na, Br, P. K. etc. were removed simultaneously during the preconcentration process so that the sensitivity for each metal was greatly improved. Optimal conditions for sample digestion, group preconcentration of trace metals and neutron activation analysis of biological and environmental samples were discussed.     

Determination of mercury in zinc ore concentrate reference materials using flow injection and cold-vapor atomic absorption spectrometry

A flow-injection, cold-vapor atomic absorption spectrophotometric method was developed for the determination of trace amounts of mercury in a proposed zinc ore concentrate Standard Reference Material (SRM 113b). The samples were digested with nitric and hydrochloric acids in closed Teflon digestion vessels. The experimental details for sample preparation and the flow injection method are discussed. The effect of matrix and various acid concentrations on the extraction and subsequent analysis of mercury were also studied. The method has a detection limit of 0.08 mug Hg/g in the sample. A certified reference material (CZN-1) was analyzed and the results obtained agreed well with the certified value.     

密闭罐溶样–氢化物发生–原子荧光光谱法测定中药中的汞和砷

建立了密闭罐溶样–氢化物发生–原子荧光光谱法测定中药中痕量汞和砷的分析方法。采用密闭罐溶解复杂基体中药样品,进行易挥发元素分析的样品前处理,技术简单,快速,能耗低。汞和砷的质量浓度分别在0~10μg/L和0~200μg/L范围内与荧光强度成线性关系,线性相关系数均大于0.99。汞、砷的检出限分别为0.014,0.086μg/L;测定结果的相对标准偏差不大于4.67%(n=5);加标回收率分别为99.0%~106.4%,95.2%~101.7%。该方法操作简便,可用于中药中汞、砷元素的质量控制。     

The determination of mercury in soils and related materials by colc-vapour atomic absorption spectrometry

A method for the determination of mercury in soils and related materials, by the cold-vapour, reduction-aeration absorption technique, is described. The mercury in the reduced sample solution is partitioned, by agitation, between the liquid phase and a fixed volume of air which is then blown through an absorption cell for measurement. Three preparative methods were developed, two of which use acid digestion and wet oxidation and the other direct oxidation in an oxygenflask combustion technique. Comparative analysis of natural samples by the three methods was used to validate the techniques developed, since no authenticated reference samples were available. For 1-g samples, the analytical range was 0.01–0.5 p.p.m.