石墨炉原子吸收光谱法测定蔬菜中铅和镉

目的:分析探讨蔬菜中铅、镉测定的最佳工作条件。方法:对西兰花与蒜苔蔬菜样品采用硝酸-高氯酸-硫酸消解,利用石墨炉原子吸收光谱法对蔬菜中的铅与镉进行测定。结果:在最佳条件下利用石墨炉原子吸收光谱法测定蔬菜中铅和镉,测得加标回收率铅98.90%,镉102.6%。结论:在对蔬菜中的铅和镉含量进行检测中,采用石墨炉原子吸收光谱法具有快捷、准确的优势,可得到满意的测定结果,满足分析要求。     

不同分析标准测试土壤铅镉结果比较

土壤的金属测试重点在于前处理,不同的消解方式对于测试结果有着较大的影响,我国目前现行的土壤铅、镉分析标准,主要选用《GB/T 17141-1997土壤质量铅、镉的测定石墨炉原子吸收分光光度法》(以下简称石墨炉法),该方法通过加入四酸加热使土壤完全消解,与《HJ 803-2016土壤和沉积物12种金属元素的测定王水提取-电感耦合等离子体质谱法》(以下简称ICP-MS法)王水提取或国外常用的王水提取法(如美国EPA 6020)在前处理上有较大区别。本文通过对不同质地的实际土壤样品分别使用四酸完全消解法和王水提取法分析铅、镉含量,比较发现上述两种前处理方法的分析结果相近,相对偏差较小。     

中药材果实、种子类药材中重金属含量的测定分析

本文对果实及种子类中药材连翘、紫苏子的铅、镉、砷和汞含量测定的方法进行了研究。样品经高氯酸、硝酸或双氧水进行消解,用原子荧光、原子吸收进行检测。测得回收率:紫苏子89.8%-97.5%;连翘86.5%-94.1%。测得精密度:紫苏子0.52%-9.2%;连翘2.2%-4.4%。并用该方法对不同产地的;连翘、枸杞子、女贞子和紫苏子、车前子、牛蒡子中的铅、镉、砷和汞含量进行了测定。结果表明:这6种中药材均含铅、镉、砷和汞,但基本上未超过国家规定的粮食和蔬菜的重金属最大允许含量。     

火焰原子吸收法测定海沙中锌、铜、铅

本文比较了三种不同酸消化处理海沙样品及不同酸度溶解残渣后用火焰原子吸收测定海沙中锌、铜、铅的方法,实验结果表明:前处理选择硝酸-高氯酸-氢氟酸法消化样品,用5%盐酸溶解残渣后测定,结果满意,方法检出限Zn0.52mg/kg,Cu0.075mg/kg,Pb1.9mg/kg,相对标准偏差(RSD)为1.3%～1.9%,加标回收率为99%～105%,该方法适用于海沙中重金属的测定。     

湿法消解-AAS测试油漆中的总铅含量

本方法建立了湿法消解原子吸收光谱仪测定油漆总铅含量的检测方法。通过对比两种体系的前处理方法的回收率,建立了用硝酸与高氯酸体系进行前处理用原子吸收光谱仪测定油漆总铅的方法,该方法的最低检测限是0.31mg/L,相对标准偏差在3.0%以内,加标氯在97.2%~101.4%,优于双氧水和高氯酸的消解体系。     

碘化钾络合MIBK萃取富集石墨炉原子吸收法测定水中的铅

本文研究了石墨炉原子吸收测定水中铅的方法。用硝酸和高氯酸溶解水中的铅,经碘化钾和MIBK络合萃取富集,用原子吸收石墨炉法测定。该方法相对标准偏差(RSD)为3.77%,检测限(DL)为0.6μg/L-1,方法回收率在92.5%-107.3%,结果令人满意。     

钛合金饰品中有害元素含量的测定

本文采用"硝酸-氢氟酸法",通过电感耦合等离子体发射光谱仪测定钛合金首饰中有害元素砷、铅、汞、镉的含量。线性相关系数均在0.9999以上,检出限在1~4mg/kg之间,加标回收率在95~105%之间,精密度在3%以内(n=6)。本方法样品前处理简单,测试结果准确。     

用高氯酸铁分光光度法测定迭氮化铅

一、前言目前测定迭氮化铅常用的方法有容量法和气量法。本方法采用EDTA溶解迭氮化铅,利用高氯酸铁不易生成铅或钡的迭氮酸盐沉淀,生成的迭氮化铁红色络合物(Fe~(3+):N_3~-=1:1)。在466nm处进行了光度测定,取得了较为满意的结果。二、原理迭氮化铅溶于EDTA,迭氮根与高氯酸铁生成迭氮化铁红色络合物(Fe~(3+):N_3~-     

ICP-AES法测定高纯铅中痕量的铁、镉、镍

本文建立了在电感耦合等离子体光谱仪上测定高纯铅中痕量铁、镉、镍的方法。采用硝酸溶解试样,用硫酸沉淀大量基体铅,在5%硝酸介质中用ICP-AES法测定上层清液,并对该方法的检出限、沉淀吸附、准确度、精密度等做了实验,测定范围为0.00002%-0.0005%,回收率为97%-107%,变异系数2%。该方法操作简便快捷,适合日常生产分析。     

用ICP-AES法测定氰化镀银溶液中铜、铁、铅、镉、钙、镁含量

以硝酸和盐酸破坏银氰化合物,使氰化物和银分别以氢氰酸气体和氯化银沉淀形式除去,用ICP-AES法连续测定了铜、铁、铅、镉、钙、镁的含量.结果表明,方法检出限为0.001 5～0.110 0 μg/mL,加标回收率在89%～124%之间.用于氰化电镀银溶液杂质元素测定,结果令人满意.     

Facilitated desorption and stabilization of sediment-bound Pb and Cd in the presence of birnessite and apatite

Desorption of lead (Pb) and cadmium (Cd) from contaminated sediments was investigated to clarify the effect of stabilizing agents on Cd and Pb desorption kinetics. The desorbed aqueous Cd and Pb concentrations and the residual amounts of Cd on the sediments in the desorption tests were best fitted to a pseudo-second-order kinetics with the highest R(2) values among the models used in the kinetic studies. The average residual Cd on sediments were 24% and 19% less in the presence of apatite and birnessite, respectively, than in the absence of them. However, the Pb desorption was not affected by the stabilizing agents. The negligible aqueous concentrations of desorbed Cd and Pb in the presence of apatite and birnessite suggest the stabilization of desorbed Cd that was facilitated by apatite and birnessite and Pb. The kinetics study with Cd shows that the rate constants are not affected, but the desorption extents are affected in the presence of apatite and birnessite. The Tessier sequential extraction method and toxicity characteristic leaching procedure indicate that Pb is more strongly bound on the stabilizing agents than Cd. Overall, birnessite and apatite can be successfully applied in remediation of Cd and Pb contaminated sediment.     

The use of the Novosol process for the treatment of polluted marine sediment

The work presented in this article concerns polluted marine sediments. The article is divided into three parts. The first part discusses existing industrial procedures of treatment. The second part introduces the Novosol((R)) process, which was used for the treatment of polluted marine sediments. This process is based on the stabilization of heavy metals in the solid matrix by phosphatation and the destruction of organic matter by calcination. Finally, after a comparison had been made between environmental results obtained on both polluted marine sediments and inert ones, treated sediments were introduced in the production of clay bricks. The results obtained show that the Novosol process leads to the immobilization of most heavy metals and can be considered as an efficient tool for the stabilisation of polluted marine sediment. Thus, the results of physical and mechanical tests as compressive strength and water absorption indicate that performances obtained were comparable to standard brick values. These results confirm that, once treated, polluted sediments can be recycled.     

Spirulina platensis feeding inhibited the anemia- and leucopenia-induced lead and cadmium in rats

In the present investigation, the effect of Spirulina platensis (Sp) was undertaken on rats fed with lead and cadmium including diet by using physiological, enzymehistochemical and stereological methods. For this aim, 50 rats were equally divided into five groups as control (C), lead (Pb), Spirulina+lead (Sp+Pb), cadmium (Cd), and Spirulina+cadmium (Sp+Cd). Red blood cell (RBC) and white blood cell (WBC) counts, packed cell volume (PCV), and haemoglobine (Hb) concentrations were determined by haemocytometric methods in blood samples collected on 30th day. Population of T lymphocyte was counted by the alpha-naphthyl acetate esterase (ANAE) staining method, and reticulocytes were counted by stereological method. The counts of RBC, WBC, and ANAE positive T lymphocyte, and the values of Hb, PCV, and MCHC were decreased in the Pb and Cd groups compared to control group. Also, the number of reticulocytes (polychromatofilic erythrocyte) increased in the Pb groups, whereas it decreased in the Cd group. On the other hand, these values were ceased by S. platensis in the treated groups. These results suggest that S. platensis supplementation may be useful in adjuvant treatment of leukemia and anemia caused by lead and cadmium toxication.     

Preparation of porous nano-calcium titanate microspheres and its adsorption behavior for heavy metal ion in water

Using D311 resin as a template, porous nano-calcium titanate microspheres (PCTOM) were prepared by a citric acid complex sol-gel method and characterized by X-ray diffraction (XRD), SEM and FTIR. The method's adsorption capabilities for heavy metal ions such as lead, cadmium and zinc were studied and adsorption and elution conditions were investigated. Moreover, taking the cadmium ion as an example, the thermodynamics and kinetics of the adsorption were studied. The results show that the microspheres were porous and were made of perovskite nano-calcium titanate. The lead, cadmium and zinc ions studied could be quantitatively retained at a pH value range of 5-8. The adsorption capacities of PCTOM for lead, cadmium and zinc were found to be 141.8 mg g(-1), 18.0 mg g(-1) and 24.4 mg g(-1) respectively. The adsorption behavior followed a Langmuir adsorption isotherm and a pseudo-second-order kinetic model, where adsorption was an endothermic and spontaneous physical process. The adsorbed metal ions could be completely eluted using 2 mol L(-1) HNO(3) with preconcentration factors over 100 for all studied heavy metal ions. The method has also been applied to the preconcentration and FAAS determination of trace lead, cadmium and zinc ion in water samples with satisfactory results.     

氧化铁颜料中微量元素的测试技术

采用原子吸收分光光度法,研究在氧化铁颜料中测定微量元素铅和镉的实验条件;使用浓盐酸直接分解氧化铁颜料样品,甲基异丁基酮对样品进行萃取,从而消除高浓度铁离子在原子吸收分光光谱测试中对铅和镉含量的干扰。结果表明:采用该测试方法,样品的溶解速度快,空白值低,具有较高的准确度和精密度。     

Enrichment/separation of cadmium(II) and lead(II) in environmental samples by solid phase extraction

A preconcentration/separation procedure is presented for the solid phase extraction of trace cadmium and lead ions as their 1-(2-pyridylazo) 2-naphthol (PAN) chelates in environmental samples on Chromosorb-106 resin, prior to cadmium and lead determinations by atomic absorption spectrometry. The preconcentration procedure was optimized by using model solutions containing cadmium and lead ions. The influences of pH of the model solutions, amounts of PAN, eluent type and volume etc. were investigated. Also the effects of the matrix constituents of the samples were also examined. Separation of cadmium and lead from real samples was achieved quantitatively. The procedure presented was checked with the analysis of microwave-digested standard reference materials (IAEA-336 Lichen and SRM 1515 Apple leaves). The preconcentration procedure was applied for the lead and cadmium contents of the natural water samples, some salts with satisfactory results (recoveries >95%, relative standard deviations <8%).     

基于ICP—MS的船用润滑油检测分析

采用电感耦合等离子体质谱法(ICP-MS)测定船用润滑油中元素钼、镍、钒、钛、钡、镉、铜、铅和锰。油液样品经加热蒸发和高温灼烧灰化处理,再加硝酸和过氧化氢湿法消解,消除了有机质对质谱测定的影响。经过优化仪器工作条件,内标校正和干扰方程处理后,所测定元素的标准曲线相关系数达0.9999以上,加标回收率为93~106%,RSD1%。     

海洋沉积物DNA提取前的简易脱腐方法研究

针对海洋沉积环境样品DNA提取中的腐殖酸去除难题,采取先脱除腐殖酸再提取DNA的策略,进行了海洋沉积物DNA提取前的简易脱腐方法研究.依据腐殖酸的理化性质, 遴选出由Tris-HCl、EDTA、Na4P2O7、NaCl、PVP、Triton X-100及脱脂奶粉组成脱腐缓冲液,有效地脱除了腐殖酸.之后采用温和的溶菌酶-蛋白酶K-SDS直接裂解法,获取了大片段(分子量21kb以上)可进行rpoB 基因PCR扩增的海洋沉积物DNA,为海洋沉积环境分子生态学研究与海洋生物活性物质开发奠定了基础.     

Preconcentration system for cadmium and lead determination in environmental samples using polyurethane foam/Me-BTANC

In this work, polyurethane foam (PUF) loaded with 2-(6'-methyl-2'-benzothiazolylazo)chromotropic acid (Me-BTANC) was packed in a minicolumn and it was used in an on-line preconcentration system for cadmium and lead determination. Optimum hydrodynamic and chemical conditions for metal sorption were investigated. The effects of several foreign substances on the adsorption of cadmium and lead were also reported. The enrichment factor obtained was 37 (Cd and Pb) for 180 s preconcentration time. The proposed procedures allowed the determination of metals with detection limits (3 sigma) of 0.80 and 3.75 microg L(-1) (0.10 and 0.47 microg g(-1) of solid sample) for cadmium and lead, respectively. The precision of the procedures was also calculated: 3.1 (Cd 10 microg L(-1)) and 4.4% (Pb 100 microg L(-1)). The accuracy of the procedure was checked by analysis of the certified reference materials Spinach Leaves and Fish Tissue. Cadmium and lead contents in environmental samples (black tea, spinach leaves, natural and tap water) were determined by applying the proposed procedure.