固体进样-冷原子吸收法测定食用明胶中的微量汞

样品直接置于石英舟中,在高纯氧气氛中燃烧,释放出的汞与齐化管中的金形成金汞齐,于900℃加热释放出汞蒸气,用冷原子吸收法测定汞的含量。方法的检出限为0.003 ng,测定结果的相对标准偏差为1.13%(n=6),加标回收率为90.5%~97.0%,并用标准样品对方法进行了确证。该方法具有良好的精密度与准确度,适用于明胶中微量汞的测定。     

固体进样-直接测汞仪法测定银精矿汞量

建立了固体进样-直接测汞仪法测定银精矿中汞的分析方法。试样无需进行样品前处理,将银精矿试样直接称量于样品舟中,在氧气气氛中,试样在分解炉中经历干燥和高温热分解,汞被还原成汞原子,再被氧气流带进汞齐化管中进行汞齐化反应,其中的汞被选择性吸附,于900℃加热释放出汞蒸汽,,汞蒸气被氧气流带入单波长光学吸收池进行原子吸收测量,方法检出限为0.007μg/g,测定结果的相对标准偏差为1.77%~3.07%(n=11),加标回收率为98.08%～102.43%。方法操作简单、快速稳定、重现性良好,适合于银精矿中微量汞的测定。     

氢化物-原子荧光光谱法连续测定锌精矿中砷、锑、铋、锡

用氢化物-原子荧光光谱法,一次性分解样品,在L-半胱氨酸存在下,实现了锌精矿中As、Sb、Bi、Sn的连续测定。其回收率分别为92．8％～105．0％、96．0％～109．3％、96．0％～111．6％和96．7％～103．7％;检出限分别为0．35、0．31、0．19和0．35μg／L。用该方法分析锌精矿样品,结果满意。     

石墨炉原子吸收光谱法测定地质样品中的痕量金

用活性炭吸附,于5％盐酸溶液中用甲基异丁基酮(MIBK)萃取金,采用斜坡升温和热解涂层石墨管技术进行地质样品中痕量金的石墨炉原子吸收光谱法测定,检出限为0．1ng/g。用该方法对标准物质进行测定,结果与标准值相符,测定结果的相对标准偏差为2．0％～6、9％(n=6)。     

氢化物原子荧光光谱法测定虾中砷和汞

建立了氢化物原子荧光法同时测定虾中砷和汞的方法。研究了样品前处理及实验条件对测定砷、汞的原子荧光强度的影响，并探讨了共存离子对测定砷、汞的干扰和消除的方法。本方法具有操作简便、快速、灵敏度高等优点，砷和汞的检出限分别为0．026μg/L和0．020μg／L；相对标准偏差分别为1．7％～9．4％和1．2％～9．4％；回收率为98％～106％。     

冷原子吸收光谱法测定化妆品中汞

应用冷原子吸收光谱法测定化妆品中痕量汞,在所选最佳测定条件下,测得方法的检出限为0．1μg·kg-1,测定下限为0．40 mg·kg-1,取4．0μg·L-1汞标液作精密度试验,算得相对标准偏差为0．6％,用标准加入法作回收率试验,所得结果在92％～97％之间。     

二氧化钛中杂质元素ICP-MS法测定的研究

本文报道了用电感耦合等离子质谱（ICP-MS）测定二氧化钛中18种杂质元素的方法。样品用浓硫酸及固体硫酸铵溶解至清亮后,加入内标元素45Sc、115In、205Tl,用内标法直接测定。讨论了二氧化钛的基体效应及钛产生的质谱干扰对测定结果的影响。方法的检出限是0．03～12．0ng／mL,相对标准偏差是1．4～12．5％,加标回收率是92．0％～103％。该法具有简便、快速、灵敏、准确等优点。     

双波长分光光度法测定牛奶中的钙

采用双波长分光光度法测定牛奶中钙离子的含量。基于在碱性缓冲液中,钙与铬黑T（EBT）-聚乙二醇溶液作用形成1：1的配合物,利用等吸收双波长消去法,消除EBT自身的干扰。在558mn和645m处测定,得吸光度差△A,钙的质量浓度在0-4．8μg／mL范围内符合比耳定律,线性回归方程为△A=0．06964c＋0．00986,产0．9989。用干灰化法处理样品,通过测定样品的△4,查得样品中钙离子的含量。该方法测定结果的相对标准偏差为1．7％～7．6％（n=5）．平均加标回收率为79．0％～98．7％。     

热解齐化-原子吸收光谱法测定红土镍矿中汞含量

经过条件试验,建立了热解齐化-原子吸收光谱法直接测定红土镍矿中汞含量的方法。样品中汞含量在57～1752μg／kg,重复测定的相对标准偏差（RSD）在1．6％～5．3％（n=11）,回收率在92．79％～94．77％,与冷原子吸收光谱法的方法间相对偏差为5．18％～11．93％。方法准确、快速、样品用量少、无试剂污染,适合于批量样品的测试,有应用和推广价值。     

铜离子标记免疫法测定甲胎蛋白

本文报道了用铜离子标记一催化放大一免疫分析法测定甲胎蛋白(AFP)。该方法用铜离子代替天然酶标记甲胎蛋白,与其抗体发生异相竞争免疫反应后,采用酸化法释放出标记物中铜离子,利用铜离子对过硫酸铵一邻甲氧基酚一硼酸缓冲液显色体系的催化作用,以催化光度法检测铜,并由此间接测定甲胎蛋白的含量。新建方法可检测10～1000ng／mL的甲胎蛋白,操作方便,成本低。该法用于血清样品AFP测定,相对标准偏差小于5．1％,样品加标回收率为87．0％～96．7％,结果满意。     

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。     

催化裂解-金汞齐富集-冷原子吸收光谱仪测定土壤样品中总汞含量

为避免汞消解过程中产生的蒸发损失及前处理过程中产生器具与样品污染,通过配制汞总量为0～2、0～15和25～1 023 ng的三种不同汞浓度系列的标准工作曲线,选取9个土壤样品、3种国家土壤有证标准物质,同一样品分别进行6组平行测定,并抽取3个土壤样品进行3种不同浓度加标回收实验,以对其方法精密度和准确度进行论证,建立了催化裂解-金汞齐富集-冷原子吸收光谱法即直接测汞仪测定土壤样品中汞含量的方法。结果显示,仪器信号值与Hg总量之间均呈良好的线性关系。根据仪器多次测定空白数据结果,按照称样量0.1 g计算,方法检出为0.09 ng/g;平行测定结果相对标准偏差均小于10%,土壤标准物质测定值与参考值均相符,不同浓度的加标回收率范围为69.0%～97.0%。方法可用于批量土壤样品中汞含量的快速测定,精密度和准确度可满足测定要求,且实验过程中无需前处理消解,操作方便、快速高效。     

液相色谱–原子荧光光谱法检测水产品中汞形态

建立了液相色谱–原子荧光光谱联用测定水产品中无机汞和甲基汞含量的方法。对影响测定结果的分析条件,如流动相组成、载流、还原剂、氧化剂、载气和屏蔽气进行了研究和优化,同时考察了该方法的有效性。结果表明:无机汞和甲基汞在质量浓度1~20 ng/m L范围内线性关系良好,相关系数分别为0.999 4,0.999 1;检出限分别为0.19,0.17 ng/m L;色谱峰面积的相对标准偏差分别为3.16%,2.16%(n=7);加标回收率分别为74%~100%,71%~91%。该方法可用于水产品中汞元素的形态分析。     

Determination of Mercury in Urine and Seawater by Flow Injection Vapor Generation Isotope Dilution Inductively Coupled Plasma Mass Spectrometry

A simple and inexpensive laboratory-built vapor generator was used with inductively coupled plasma mass spectrometry (ICP-MS) for the determination of mercury in urine and seawater samples. The applications of vapor generation ICP-MS alleviated the non-spectroscopic interferences and the sensitivity problem of mercury determination encountered when the conventional pneumatic nebulizer was used for sample introduction. The concentration of mercury was determined by isotope dilution method. The isotope ratio of mercury was calculated from the peak areas of each injection peak. The repeatability of the peak areas and isotope ratio determinations of seven consecutive injections of 1 ng mL^?1 Hg solution were 2.3% and 2.2%, respectively. This method has a detection limit of 0.07 ng mL^?1 for mercury. This method was applied to determine mercury in a CASS-3 nearshore seawater reference sample, NASS-4 open ocean seawater reference sample, NIST SRM 2670 freeze-dried urine reference sample and several urine and seawater samples collected from National Sun Yat-Sen University. The results for the reference samples agreed satisfactorily with the reference values. Results for other samples analyzed by the isotope dilution method and the method of standard additions agreed satisfactorily. Precision was better than 10% for most of the determinations.     

微波萃取高效液相色谱-冷原子荧光光谱法测定沉积物中甲基汞和无机汞

建立了微波萃取高效液相色谱-冷原子荧光光谱法(MAE-HPLC-CVAFS)测定沉积物中甲基汞(MeHg+)和无机汞(Hg2+)的方法。以0.1%(V/V)2-巯基乙醇为萃取剂,用于沉积物样品中汞形态的萃取,在80℃下萃取8 min,萃取液直接注入HPLC-CVAFS系统分析。在优化条件下,MeHg+和Hg2+的检出限分别为0.58和0.48 ng/g;加标回收率分别为96.2%和95.8%;RSD(n=6)分别为5.7%和4.1%。对标准参考物质(IAEA-405和ERM-CC580)的分析结果与推荐值一致。本方法简单、快速、准确、检出限低,抗干扰能力强,具有很好的实用性和推广价值。     

Mercury speciation in sea food by flow injection cold vapor atomic absorption spectrometry using selective solid phase extraction

An on-line inorganic and organomercury species separation, preconcentration and determination system consisting of cold vapor atomic absorption spectrometry (CV-AAS or CV-ETAAS) coupled to a flow injection (FI) method was studied. The inorganic mercury species was retained on a column (i.d., 3 mm; length 3 cm) packed to a height of 0.7 cm with a chelating resin aminopropyl-controlled pore glass (550 A) functionalized with [1,5-bis (2 pyridyl)-3-sulphophenyl methylene thiocarbonohydrazyde] placed in the injection valve of a simple flow manifold. Methylmercury is not directly determined. Previous oxidation of the organomercurial species permitted the determination of total mercury. The separation of mercury species was obtained by the selective retention of inorganic mercury on the chelating resin. The difference between total and inorganic mercury determined the organomercury content in the sample. The inorganic mercury was removed on-line from the microcolumn with 6% (m/v) thiourea. The mercury cold vapor generation was performed on-line with 0.2% (m/v) sodium tethrahydroborate and 0.05% (m/v) sodium hydroxide as reducing solution. The determination was performed using CV-AAS and CV-ETAAS, both approaches have been used and compared for the speciation of mercury in sea food. A detection limit of 10 and 6 ng l(-1) was achieved for CV-AAS and CV-ETAAS, respectively. The precision for 10 replicate determinations at the 1 microg l(-1) Hg level was 3.5% relative standard deviation (R.S.D.), calculated from the peak heights obtained. Both approaches were validated with the use of two certified reference materials and by spiking experiments. By analyzing the two biological certified materials, it was evident that the difference between the total mercury and inorganic mercury corresponds to methylmercury. The concentrations obtained by both techniques were in agreement with the certified values or with differences of the certified values for total Hg(2+) and CH(3)Hg(+), according to the t-test for a 95% confidence level. It is amazing how this very simple method is able to provide very important information on mercury speciation.     

Comparison of the Adsorbed Mercury Screening Method with Cold-Vapor Atomic Absorption Spectrophotometry for Determination of Mercury in Soil

ABSTRACT

A field screening method for the determination of elemental mercury in environmental soil samples involves the thermal desorption of the mercury from the sample onto gold and then the thermal desorption from the gold to a gold-film mercury vapor analyzer. This field screening method contains a large number of conditions that could be optimized for the various types of soils encountered. In this study, the conditions were optimized for the determination of mercury in silty clay materials, and the results were comparable to the cold-vapor atomic absorption spectrophotometric method of determination. This paper discusses the benefits and disadvantages of employing the field screening method and provides the sequence of conditions that must be optimized to employ this method of determination on other soil types.     

捕汞金管富集-冷原子荧光光谱法测定空调颗粒物中的汞

对国产原子荧光仪进样系统进行改造,采用在线热解样品捕汞金管富集冷原子荧光法测定空调颗粒物中的汞。试样热解温度为700～750℃,捕汞金管释放温度为550℃,试样载气流速为120 mL/min。方法检出限为1 pg,汞含量在0～1.5 ng范围内呈线性关系,测定标准偏差为2.23%。用国家土壤标准GBW07410中的汞验证了方法的准确性,并对某医院空调颗粒物中汞含量进行了分析。