Errors in atomic absorption spectrophotometric determination of Pb,Zn, Ni and Co in geologic materials

Errors in atomic absorption spectrophotometric determinations of Pb, Zn, Ni and Co may occur due to the presence of Fe, Al, Ca, Mg, Na and K in the sample solution. At low concentrations of trace element in solution (i.e., up to about 1 p.p.m.) and low concentrations of major elements (up to about 4,000 p.p.m. total cations), the main source of interference is enhancement due to background absorption; this may be corrected by the hydrogen continuum or by use of a non-absorbing wavelength. At higher concentrations of trace element the enhancement due to molecular absorption is partly or completely nullified through suppression caused by major element interference. Similarly, at higher concentrations of major elements, suppression occurs which is probably a function of atomizer efficiency. In these situations, correction for total molecular absorption results in a residual negative error.The errors in determination of Pb, Zn, Ni and Co in geological materials are often ignored in exploration geochemistry work. This restriction on the accuracy of the analytical data is becoming more important with the increasing use of exploration methods based on rock analyses. The errors may be minimized by ensuring that the concentration of both trace element and major element in solution is too low to cause significant suppression effects. Under these circumstances, reasonable results should be obtained through correction for background absorption.     

用火焰原子吸收光谱法连续测定银、铜、锌

试样经NH4F,HCl,HNO3分解的酸性介质中,选用NaCl做配合剂,Ag,Cu,Zn可以同时进入溶液。但由于上机测定时背景吸收严重,而所使用的原子吸收分光光度计不能扣除背景。选用硫脲做配合剂时,可使Ag生成稳定无色的Ag[CS(NH2)2]Cl配合物,从而避免溶液中生成AgCl沉淀,同时也使测定时的酸度得到有效的降低。原来需要分别取样、溶解和测定Ag,Cu,Zn的操作,得以在同一份样品中完成。用火焰原子吸收分光光度计连续测定Ag,Cu,Zn,方法的测定范围分别为Ag0 n×10-6～5000 0×10-6;Cu0 00n%～n 000%;Zn0 00n%～n 000%。     

萃取富集-火焰原子吸收法测定碳酸钙中铅和镉

将碳酸钙试样用盐酸溶解后,在0.6mol/L的盐酸介质中,用KI-MIBK萃取试样中微量的铅和镉,有机相用原子吸收分光光度法测定。该方法测定铅的相对标准偏差为2.38%-6.31%,回收率为96.5%-97.0%;测定镉的相对标准偏差为4.50%-5.52%,回收率为96%-102.8%。结果可靠,具有灵敏、准确、快速、选择性好等优点。适用于碳酸钙中铅、镉的测定。     

用ICP-AES法测定银精矿中银铜铅锌砷

研究了在王水介质中用ICP－AES法同时测定银精矿中银、铜、铅、锌、砷的分析方法，进行了加标回收试验，回收率为92％－107％，相对标准偏差2．3％－11％，确定了各元素的测定下限，与行业标准进行了方法对照实验。本方法已用于矿样的测定。     

发射光谱法测定化探样品中的Cu、Pb、Zn、Co、Ag、Sn、Mo和B

以Al2O3、K2S2O7、NaF、C作为缓冲剂与样品混匀,装入石墨电极中,以平头石墨电极为上电极,样品电极为下电极进行摄谱,由光电译谱仪测定谱线的黑度值,以锗为内标用内标法测定样品中Cu、Pb、Zn、Co、Ag、Sn、Mo和B的质量分数。     

Competitive adsorption of Cd,Cu, Pb and Zn by different soils of Eastern China

Simultaneous competitive adsorption behavior of Cd, Cu, Pb and Zn onto nine soils with a wide physical–chemical characteristics from Eastern China was measured in batch experiments to assess the mobility and retention of these metals in soils. In the competitive adsorption system, adsorption isotherms for these metals on the soils exhibited significant differences in shape and in the amount adsorbed. As the applied concentration increased, Cu and Pb adsorption increased, while Cd and Zn adsorption decreased. Competition among heavy metals is very strong in acid soils with lower capacity to adsorb metal cations. Distribution coefficients (K _dmedium) for each metal and soil were calculated. The highest K _dmedium value was found for Pb and followed by Cu. However, low K _dmedium values were shown for Zn and Cd. On the basis of the K _dmedium values, the selectivity sequence of the metal adsorption is Pb > Cu > Zn > Cd and Pb > Cu > Cd > Zn. The adsorption sequence of nine soils was deduced from the joint distribution coefficients (K _dΣmedium). This indicated that acid soils with low pH value had lower adsorption capacity for heavy metals, resulting in much higher risk of heavy metal pollution. The sum of adsorbed heavy metals on the soils could well described using the Langmuir equation. The maximum adsorption capacity (Q _m) of soils ranged from 32.57 to 90.09 mmol kg⁻¹. Highly significant positive correlations were found between the K _dΣmedium and Q _m of the metals and pH value and cation exchange capacity (CEC) of soil, suggesting that soil pH and CEC were key factors controlling the solubility and mobility of the metals in soils.     

阴离子交换色谱分离和测定微量单矿物方铅矿和闪锌矿中铜、铅、锌、银、铋、镉、锰、钴和镍等元素

微量单矿物方铅矿和闪锌矿中主体元素和痕量元素的多项分析,作者根据金属元素在阴离子交换树脂上与在盐酸、氢溴酸、硝酸、硫酸溶液之间的行为差别,试验了用阴离子交换色谱分离的条件,选用不同浓度的盐酸溶液洗提铜、钴、镍、锰、铅和银;氢溴酸溶液洗提锌;硝酸溶液洗提镉;最后用硫酸溶液洗提铋。本文所拟定的分析流程简便,试用于微量单矿物方铅矿和闪锌矿中九个元素的测定,效果较好。 实验部分 一、主要试剂     

深孔电极发射光谱法测定地质样品中Be、B、Pb、Mo、Sn、Cu、Ag、Zn

本法是在样品中加入适量的缓冲剂,使难发挥元素Be形成易挥发的氟化物,与B、Pb、Mo、Sn、Cu、Ag、Zn等元素在同一时间内蒸发,利用深电孔极的分馏效应,有效地降低光谱背景以及被测元素的检出限。加入内标元素,提高了方法的准确度和精密度。采用深孔电极,取样量大,代表性好。一次摄谱,同时检测多个元素,大大提高了工作效率,又减少了测试费用。方法操作简便,适合于大批量样品的测试。检出限ω(B)/10-6分别达到:Be:0.50、B:0.91、Sn:0.50、Ag:0.02等,均满足《覆盖区多目标地球化学调查样品测试及质量监控暂行规定》规定。     

Contamination of the biological compartment in the Seine estuary by Cd, Cu, Pb, and Zn

A study of contamination of the biological compartment of the Seine estuary was carried out by measuring the concentrations of cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) in 29 estuarine and marine species belonging to 6 phyla. Species came from three main biological zones of the estuary: the Seine channel (copepods, mysids, shrimps, and fish), the intertidal mudflats (Macoma balthica community), and the subtidal mudflats (Abra alba community). Two fish species, the bass (Dicentrarchus labrax) and the flounder (Platichthys flesus), were also selected for analyses. A comparison of metal concentrations in estuarine species of the Seine with those found in the same species collected on contaminated and non-contaminated sites showed a contamination of the estuary by Cu, Zn, and Pb. For Cd, the contamination is mainly observed in bivalves, although the concentrations observed were low and less than 2 μg g^?1 d.w. High concentrations of Cu were found in copepods, shrimps, and fish. Pb contamination was mainly found in species living in the Seine channel where the copepodEurytemora affinis shows an average concentration of 22 μg g^?1 d.w. High concentrations of Pb (>10 μg g^?1 d.w.) were found in deposit-feeders benthic invertebrates. Elevated levels of Zn were seen in all species collected in the Seine estuary, including fish and in particular small flounder. The concentrations of Cd, Cu, Pb, and Zn found in edible estuarine species (shrimp and fish) were in the same order of magnitude than those found in fish and shrimps fished along the French coast.     

火焰原子吸收法测定化探样品中的银铜铅锌

样品经硝酸、氢氟酸、高氯酸分解，制成硝酸溶液，经巯基棉层析柱过滤富集Ag，并用2mol／LHBr溶液洗脱，用火焰原子吸收法测定洗脱液中的Ag和滤液中的Cu，Pb，Zn。用该法测定化探样品中银和铜铅锌，检出限低，结果准确度和精密度均令人满意。     

无高氯酸常压酸溶-ICP-MS法同时测定土壤中的As、Cd、Pb、Cr、Zn、Cu、Ni

采用无高氯酸常压酸溶分解土壤样品,利用等离子体质谱法可以1次溶矿测定As、Cd、Pb、Cr、Zn、Cu、Ni 7个重金属元素,具有较高的分析效率、较好的分析质量、较低的分析成本。实验表明,试样溶液中氯的含量对分析元素信号有较大影响。采用硝酸-氢氟酸-硫酸-过氧化氢分解样品以避免引入氯离子,从而能有效避免Cr、As元素在样品分解过程中的损失和氯离子产生的质谱干扰。Cd的测定需采用干扰校正公式扣除Sn的干扰。对于As元素,若试样溶液中不含或仅含微量的氯离子,采用标准模式测定即可得到理想的分析结果,否则必须采用CCT模式进行测定。除As以外的其他元素不论在标准模式或CCT模式下均能得到理想的分析结果。     

Influence of operating conditions on the removal of Cu, Zn, Cd and Pb ions from wastewater by adsorption

Nile Rose Plant was used to study adsorption of several cations (Cu²+, Zn²+, Cd²+ and Pb²+) from wastewater within various experimental conditions. The dried leaves of Nile Rose Plant were used at different adsorbent/ metal ion ratios. The influence of pH, contact time, metal concentration, and adsorbent loading weight on the removal process was investigated. Batch adsorption studies were carried out at room temperature. The adsorption efficiencies were found to be pH dependent, increasing by increasing the pH in the range from 2.5 to 8.5 exept for Pb. The equilibrium time was attained within 60 to 90 min. and the maximum removal percentage was achieved at an adsorbent loading weight of 1.5 g/50 mL mixed ions solution. Isothermal studies showed that the data were best fitted to the Temkin isotherm model. The removal order was found to be Pb²⁺> Zn²⁺> Cu²⁺> Cd²⁺. The surface IR-characterization of Nile rose plant showed the presence of many functional groups capable of binding to the metal cations.     

巯基棉分离富集ICP-OES测定岩盐矿中的水溶性铜铅锌镉

盐岩矿的水溶法开采是获得人类生活必需品和重要工业原料——盐的重要途径之一。在水溶法开采中,岩盐矿中的水溶性重金属会随着母液到达地表环境和后续的岩盐产品中,可能对地表环境造成污染和危害人体健康,故对岩盐矿中水溶性重金属的检测非常重要。岩盐矿中的水溶性铜铅锌镉含量较低,而盐分含量过高,过高的盐分含量会影响ICP-OES的雾化效率,故很难用ICP-OES直接测量重金属含量。本文以巯基棉为吸附材料,从溶液pH、洗脱液浓度、洗脱液体积等方面研究了分离富集岩盐矿中水溶性铜铅锌镉的实验条件。结果表明,在pH=7的介质中,巯基棉对铜铅锌镉有良好的吸附性能,被吸附的铜铅锌镉可用7 m L盐酸(15%)定量洗脱,溶液中的钠对吸附无明显影响。对解吸后的溶液,铜铅锌镉的回收率均≥92.2%,钠回收率仅0.04%,基本实现了铜铅锌镉与钠的分离,达到了ICP-OES检测要求。     

Uptake of Zn,Cu, Pb,and Cd by water hyacinth in the initial stage of water system remediation

The removal efficiency of water hyacinth for Zn, Cu, Pb and Cd after their entry into an undisturbed fresh water body was studied using minicosms placed within a reservoir. Variable parameters were water pH (6 or 8), single or multi-metal additions, and the plant biomass. The initial concentrations of Zn, Cu, Pb and Cd in water (500, 250, 250 and 50 μg/L, respectively) quickly decreased in the order Pb ≈ Cu ? Cd ≈ Zn in the first days. Metal removal was more efficient at pH 8 than at pH 6, and it was only slightly higher for single metals compared to multi-metal additions. After 8 days the remaining amounts of metals relative to their initial concentrations for multi-metal pollution treatments were 8% and 24% (Cu), 11% and 26% (Pb), 24% and 50% (Cd), and 18% and 57% (Zn) at pH 8 and pH 6, respectively. Increasing plant biomass promoted faster metal removal. The bioconcentration factor (the ratio of the metal concentration in whole plants to the initial metal concentration in water) exceeds 2000 for all metals (with the exception of Zn and Cd at pH 6). It was concluded that the water hyacinth can be successfully used for fast removal of metals in the initial stage of water body remediation.     

The long-term fate of Cu, Zn, and Pb adsorption complexes at the calcite surface: An X-ray absorption spectroscopy study

In this study, the speciation of Zn²⁺, Pb²⁺, and Cu²⁺ ions sorbed at the calcite surface was monitored during a 2.5-year reaction period, using extended X-ray absorption spectroscopy to characterize metal speciation on the molecular scale. Experiments were performed using pre-equilibrated calcite-water suspensions of pH 8.3, at metal concentrations below the solubility of metal hydroxide and carbonate precipitates, and at constant metal surface loadings. The EXAFS results indicate that all three metals remained coordinated at the calcite surface as inner-sphere adsorption complexes during the 2.5-year ageing period, with no evidence to suggest slow formation of dilute metal-calcite solid solutions under the reaction conditions employed. All three divalent metals were found to form non-octahedral complexes upon coordination to the calcite surface, with Zn²⁺ adsorbing as a tetrahedral complex, Cu²⁺ as a Jahn-Teller distorted octahedral complex, and Pb²⁺ coordinating as a trigonal- or square-pyramidal surface complex. The non-octahedral configurations of these surface complexes may have hindered metal transfer from the calcite surface into the bulk, where Ca²⁺ is in octahedral coordination with respect to first-shell O. The use of pre-equilibrated calcite suspensions, with no net calcite dissolution or precipitation, likely prevented metal incorporation into the lattice as a result of surface recrystallization. The results from this study imply that ageing alone does not increase the stability of Zn²⁺, Pb²⁺, and Cu²⁺ partitioning to calcite if equilibrium with the solution is maintained during reaction; under these conditions, these metals are likely to remain available for exchange even after extended sorption times.     

Field determination of copper, manganese and Zinc in sulphide materials by flameless atomic absorption spectrometry

A field-portable analytical method is described for the semi-quantitative determination of Cu, Mn and Zn in oceanic sulphide minerals. Samples were prepared on board ship and analyzed using the AAZ-2 field portable atomic absorption spectrophotometer. The method has general applicability to a variety of field locations at sea or on land. Analyte concentrations ranging from the ppm to percent levels could be determined by selecting the appropriate analytical wavelengths and sample dilution factors. Samples were dissolved using hydrochloric and nitric acids in sealed teflon vessels. Concentrations of Cu, Mn and Zn were determined with an accuracy of approximately 10% when field results were compared with determinations subsequently carried out on the same samples in the laboratory by flame atomic absorption methods.     

电感耦合等离子体发射光谱法同时测定锡矿石中锡钨钼铜铅锌

锡矿石是难分解的矿物,共生与伴生元素多,其中的锡钨钼在单一盐酸溶液中易沉淀,准确测定锡矿石中的主次量元素一直是分析技术难点。本文以过氧化钠为熔剂,高温熔融样品,在酒石酸-盐酸-双氧水体系中进行酸化,选用该矿种中仅含有少量的钴作为内标,建立了电感耦合等离子体发射光谱同时测定锡矿石中锡钨钼铜铅锌的分析方法。方法线性范围为0.00~40.0 mg/L;方法检出限为锡10 mg/kg,钨30 mg/kg,钼3.3 mg/kg,铜12 mg/kg,铅15 mg/kg,锌40 mg/kg;方法精密度(n = 9)小于5.0%,实际样品的测定值与传统化学方法及国家标准方法的测定值吻合较好。本方法采用过氧化钠碱熔锡矿石,溶样彻底,并省去了氢氟酸挥发硅的蒸酸过程,节约了样品处理时间;采用酒石酸-双氧水-盐酸体系溶解熔融物,有利于溶液中的锡钨钼形成稳定的络合物,避免了单纯盐酸体系下产生钨酸、钼酸和锡酸沉淀导致测定结果偏低的问题。     

Determination of Ga,Ge, Mo,Ag, Cd,In, Sn,Sb, W,Tl and Bi in USGS Whole‐Rock Reference Materials by Standard Addition ICP‐MS

A procedure for determining a wide range of chalcophile and siderophile elements in typical crustal rocks using standard addition and ICP‐SFMS (inductively coupled plasma sector field mass spectrometry) is presented. New results for Ga, Ge, Mo, Ag, Cd, In, Sn, Sb, W, Tl and Bi abundances in USGS whole‐rock reference materials AGV‐2, BHVO‐1, BIR‐1, G‐2, GSP‐1 and W‐2 are reported using this analytical procedure. Intermediate precision of means based on multiple dissolved aliquots of each USGS reference material was 10% RSD or better for Ga, Ge, In and Sn in all, and similarly good for Ag, Cd, Sb, Tl and Bi in most reference materials. Poorer intermediate precision of Mo and W measurements in several reference materials is probably due to higher analytical blanks on these elements and powder heterogeneity due to a sulfide‐related nugget effect in the specific case of Mo in GSP‐1. Results for all elements fell within the range of available published data with the exception of Ag, which yielded systematically higher concentrations than found in the literature for five of the six reference materials, likely reflecting interference from unresolved polyatomic species.     

巯基棉分离富集ICP-AES法测定高盐冶金废水中痕量铅镉铜银

矿山企业的冶金废水含有多种污染环境的金属元素,必须经过化学沉淀法处理达标后排放。冶金废水经化学沉淀后引入了大量盐分,使得金属元素含量变得极低给分析测试造成困难。针对此类高盐冶金废水,本文采用巯基棉分离富集其中的金属元素,建立了运用电感耦合等离子体光谱(ICP-AES)测定铅、镉、铜、银的分析方法。通过优化实验表明,巯基棉可有效地分离实际样品中大量存在的硫酸根离子和钠离子基体,富集待测元素的效果显著,硫酸根离子和钠离子回收率均小于0.05%,待测元素的回收率在88.7%~113.0%之间。实验条件方面,待测溶液的pH值对巯基棉吸附有较大的影响,使用巯基棉富集前应将溶液调节至适宜的pH值;待测溶液在富集柱中的流速和洗脱剂盐酸的浓度对分离富集效果也有一定的影响。在最佳实验条件下,本法回收率为95.0%~102.0%,精密度(RSD)为3.1%~9.4%,方法快速简便、准确度高,能够满足冶金废水中痕量金属元素的检测需求。     

电感耦合等离子体发射光谱法多向观测同时测定锑矿石中锑砷铜铅锌

采用王水溶矿方法分解试样,在15％的王水介质中,建立了电感耦合等离子体发射光谱法测定锑矿石中锑、砷、铜、铅和锌的方法.通过选择光谱干扰少的分析线,结合径向衰减或径向观测方式,可减小样品稀释倍数,准确测量高含量的锑、砷;结合轴向观测方式,可准确测量低含量的铜、铅、锌.方法的检出限为:锑5.0 μg/g,砷5.0μg/g,铜0.5 μg/g,铅1.0 μg/g,锌0.5μg/g.建立的方法改善了测定的准确度,相对标准偏差( RSD,n=12)小于2.8％,方法回收率为97.5％ ～ 102.5％.建立的方法经锑矿石国家一级标准物质验证,测定结果与标准值吻合,具有测定含量范围宽、分析简便快速、结果准确等优点.