测定土壤中重金属元素的样品消解方法

探讨适用于重金属分析的土壤样品处理方法。利用原子吸收光谱法测定土壤中Cu,Mn,Ni,Pb和Zn 5种元素的含量,对电热板、微波和水浴3种消解方法进行比较,结果表明:3种样品预处理方法的检出限、准确度和精密度均满足分析检测要求。其中,电热板法样品消解较彻底,Cu和Pb的测定结果准确,但试剂、时间和人力消耗多,且为敞开式消解,高温及产生的大量酸雾危害环境与健康;微波法为密闭式消解,样品和试剂用量少,耗时短,自动化程度高,消解彻底,安全环保,Mn的测定结果准确,但成本高,不适于大批量样品分析;水浴法为半封闭式消解,简单易行,Ni和Zn的测定结果准确,但消解剂中不含氢氟酸,不适于含有大量硅酸盐样品的处理。     

微波消解-电感耦合等离子体质谱法测定土壤中10种重金属元素

利用硝酸、盐酸、氢氟酸混合液和微波消解仪密闭消解样品，建立了一种微波消解-电感耦合等离子体质谱（ICP-MS）法同时测定土壤中铜、铅、锌、锰、钒、铬、镉、镍、锡、铊10种重金属的分析方法。取0.100 0 g土壤样品于消解罐中，采用4 mL硝酸+1 mL盐酸+1 mL氢氟酸消解体系按照设定程序进行微波消解，冷却，定容后利用电感耦合等离子体质谱法进行。结果表明，以铑元素作为内标，10种重金属元素在一定的质量浓度范围内与其信号强度呈线性关系，线性相关系数均不小于0.999 8，检出限为0.010～0.92 mg/kg。对3种标准物质进行测定，测定值的相对标准偏差为2.89%～7.72%(n=10)，相对偏差为-5.95%～4.11%。该方法分析流程简单，工作效率高，检出限低，适合大批量土壤样品的多元素同时分析。     

测定土壤中重金属元素时前处理方法的改进

建立了一种微波消解前处理技术的半消解法消解样品,采用原子吸收光谱法和原子荧光光谱法同时测定土壤中主要重金属元素铜、锌、镉、砷、汞的方法,检测土壤标准物质GSS-3、GSS-5、GSS-20,结果显示测定均值在标准差允许范围内,相对标准偏差小于8.5%(n=4),是土壤重金属元素快速检测的可选方法。     

微波消解-电感耦合等离子体质谱法测定土壤中9种重金属元素

建立微波消解-电感耦合等离子体质谱法测定土壤中的钒、铬、钴、镍、铜、锌、钼、镉、铅9种重金属元素。采用硝酸-氢氟酸-过氧化氢三酸体系微波消解土壤样品后,加入高氯酸于赶酸仪中对样品进行处理,定容至50 mL容量瓶中,混匀至澄清,取分液用电感耦合等离子体质谱仪对土壤中的9种重金属元素进行定量分析。探讨了称样质量、样品处理试剂、干扰效应、溶液酸度对测定结果的影响,各元素的质量浓度在0～100.0μg/L范围内与其对应的信号强度线性关系良好,相关系数为0.999 2～0.999 9,方法检出限为0.013～1.0 mg/kg。对土壤标准物质进行测定,测定值的相对标准偏差为0.82%～4.73%(n=6),测定值与标准值相吻合,相对误差为-12.1%～11.11%。样品处理过程中未使用盐酸,该法适于土壤中重金属元素的含量测定。     

测定土壤中重金属元素时前处理方法的改进

建立了一种微波消解前处理技术的半消解法消解样品,采用原子吸收光谱法和原子荧光光谱法同时测定土壤中主要重金属元素铜、锌、镉、砷、汞的方法,检测土壤标准物质GSS-3、GSS-5、GSS-20,结果显示测定均值在标准差允许范围内,相对标准偏差小于8.5%(n=4),是土壤重金属元素快速检测的可选方法。     

微波消解-电感耦合等离子体原子发射光谱(ICP-AES)法同时测定土壤中主次元素

建立了微波消解-电感耦合等离子体原子发射光谱(ICP-AES)法同时测定土壤中多种主次元素的分析方法。采用硝酸-氢氟酸-双氧水体系在微波消解仪中消解土壤样品,待消解完成后加入高氯酸驱赶氢氟酸,盐酸溶解盐类物质,将土壤中所有元素的矿物晶格破坏使待测溶液全部进入试液,采用ICP-AES法测定。通过筛选合适分析谱线和合理设置背景扣除位置提高样品分析中的精密度和准确度。选用国家土壤标准物质进行方法验证,绝大多数实验结果与标准值吻合,相对标准偏差(RSD)小于5%。方法具有同时测定土壤样品中多种元素、试剂用量少、操作简单等优点,表明方法适合大批量土壤中主次元素的快速检测。     

微波消解-电感耦合等离子体原子发射光谱(ICP-AES)法同时测定土壤中主次元素

建立了微波消解-电感耦合等离子体原子发射光谱(ICP-AES)法同时测定土壤中多种主次元素的分析方法。采用硝酸-氢氟酸-双氧水体系在微波消解仪中消解土壤样品,待消解完成后加入高氯酸驱赶氢氟酸,盐酸溶解盐类物质,将土壤中所有元素的矿物晶格破坏使待测溶液全部进入试液,采用ICP-AES法测定。通过筛选合适分析谱线和合理设置背景扣除位置提高样品分析中的精密度和准确度。选用国家土壤标准物质进行方法验证,绝大多数实验结果与标准值吻合,相对标准偏差(RSD)小于5%。方法具有同时测定土壤样品中多种元素、试剂用量少、操作简单等优点,表明方法适合大批量土壤中主次元素的快速检测。     

微波消解-电感耦合等离子体发射光谱法同时测定土壤中主次金属元素

建立微波消解-电感耦合等离子体发射光谱法同时测定土壤中多种主次元素的分析方法。采用硝酸-氢氟酸-双氧水体系在微波消解仪中消解土壤样品,待消解完成后加入高氯酸驱赶氢氟酸,盐酸溶解盐类物质,将土壤中所有元素的矿物晶格破坏使待测溶液全部进入试液,采用电感耦合等离子体发射光谱进行测定。通过筛选合适分析谱线和合理设置背景扣除位置提高样品分析中的精密度和准确度。选用国家土壤标准物质进行方法验证,绝大多数实验结果与标准值吻合,RSD小于5%。本方法具有同时测定土壤样品多种元素、试剂用量少、操作简单等优点,表明该方法适合大批量土壤中主次元素的快速检测。     

ICP-OES测定金矿尾矿区优势植物中的重金属元素

研究了3种消解方法对测定金矿尾矿区优势植物中多种重金属元素的消解效果。采用电热板敞开消解、高压罐密闭消解和微波消解对秭归月亮包金矿尾矿区节节草、五节芒和蜈蚣草3种优势植物进行前处理,ICP-OES测定Cr,M n,Zn,Cu,Ni,Pb,M g,Al和Fe 9种重金属元素含量,实验结果表明,3种消解方法都能满足测定要求,其中微波消解法的准确度、精密度和回收率最好;高压罐密闭消解试剂用量少、元素损失少;电热板敞开消解法波动性较大,但适于大批量样品分析。在实际分析中,应根据样品量、重金属元素含量和结果准确度等要求选择合适的消解方法。检测结果表明,矿区的优势植物五节芒、节节草和蜈蚣草具有较强的重金属耐性。     

电感耦合等离子体质谱(ICP-MS)法测定农产品地土壤中铅、镉、铬消解方法的改进

采用赶酸电热板消解农产品地土壤中的重金属,电感耦合等离子体质谱(ICP-MS)法同时测定土壤中的铅、镉、铬。研究了酸体系及酸用量、赶酸电热板的升温程序,确定了最佳消解条件。通过统计50个批次土壤样品中加入的质控样,做出质控图,结果表明:各元素测定值均落在中心附近、上下警告线之内,批次内平行样品各元素相对标准偏差均小于5%。方法克服了传统的电热板消解法的缺点,弥补了高压罐消解法和微波消解法的不足,方法快速、准确,适合于大批量样品的分析。     

微波消解凯氏定氮法快速测定酱油中全氮

研究了凯氏定氮法测定酱油中全氮时样品的微波消解方法,进行了微波消解条件的选择及消解结果精密度试验,并与国家标准方法对比,验证了方法的准确度。试验结果表明,消解完全仪需20min,相对标准偏差均小于2%（n=7）,回收率范围为96%～103%,经t检验,微波溶样法与国家标准凯氏定氮法的测定结果无显著性差异。     

微波技术在分析化学中的应用

对微波技术在现代分析化学中的应用作了综述,主要涉及在试样干燥,试样消解,微波萃取,微波雾化等方面的应用,微波技术的优点反映在高效、快速,操作控制较简单,及无化学污染等。对该技术的未来应用的展望也作了简述（引用文献46篇）。     

微波制样的应用

介绍了微波制样在分析化学中的应用，包括微波试样消解，微波加热水样测定CODcr，微波加热水解蛋白质测定各种氨基酸，以及微波萃取等。特别是对微波试样消解在应用中的一些问题，作了较详细的叙述。     

Conductive carbon tape as a sample platform for microwave-based MALDI MS detection of proteins and phosphoproteins

In this study, we developed a novel microwave-assisted protein preparation and digestion method for matrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spectrometry analysis and identification of proteins that involves using conductive carbon tape as a sample platform for sample preparation (reduction and alkylation) and digestion under microwave heating and as a plate for MALDI analysis. This method allows for the enzymatic digestion products of proteins to be directly analyzed by MALDI mass spectrometry and results in a marked reduction in sample loss. Our protocol requires only a small volume (1 μL) of reaction solvent, which increases the frequency of enzyme-to-protein contact, thereby resulting in more efficient digestion of sample than conventional in-solution digestion methods. To test this protocol, we used magnetic iron (II, III) oxide nanoparticles as concentrating probes to enrich phosphopeptides from a mixture of peptides in enzymatically digested protein samples. We found that the one-pot on-tape-based protein preparation and digestion under microwave heating combined with the on-tape-based enrichment method not only dramatically reduced the time required for phosphopeptides analysis but also allowed for the simultaneous identification of phosphoproteins. The advantages of our protocol include ease of use, high digestion efficiency, high specificity, and rapid (15 min) identification of proteins and enrichment of phosphopeptides in a mixture of enzymatically digested protein samples.     

微波消解-分光光度法测定大豆中的硼量

研究了分光光度法测定大豆中的硼时样品的微波消解方法。建立了合理的分析步骤。进行了微波消解条件的选择及方法的精密度、准确度试验。试验结果表明:消解完全仅需20 min,相对标准偏差均小于7.6%,其方法的加标回收率为92%~105%。     

脉冲加热-热导法测定氮化锰粉末中的氮含量

介绍采用TC-600氧氮分析仪测定氮化锰粉末中氮的方法。对氮化锰粉末样品,采用手动模式进样。对加热功率、称样量、空白值等测定条件进行试验,确定了最佳测定条件。氮的加标回收率为98.18%~101.10%,测定结果的相对标准偏差小于1%(n=9)。该方法测定结果与化学法测定结果一致。     

Ultrasound assisted pseudo-digestion for determination of iron and manganese in citric acid fermentation mediums by electrothermal atomic absorption spectroscopy

A sensitive, simple and rapid method for ultra-trace determination of iron and manganese based on ultrasound assisted pseudodigestion in citric acid fermentation medium samples (beet and cane molasses and raw sugar based mediums) is described. Parameters influencing pseudo-digestion, such as sonication time, sample mass and solvent system were fully optimized. Final solutions obtained upon sonication were analyzed by electrothermal atomic absorption spectrometry (ETAAS). The best conditions for metal pseudo-digestion were as follows: a 25, 30 and 20 min sonication time for beet molasses, cane molasses and raw sugar based medium samples, respectively, 0.7 g sample mass of raw sugar based samples, 0.5 g sample mass of molasses based samples and an extraction mixture of concentrated HNO₃-H₂O₂, in 25 mL of solvent. Analytical results obtained for the two metals by ultrasound assisted pseudo-digestion and conventional wet digestion methods showed a good agreement. This method reduces the time required for all treatments (heating to dryness, cooling and separation) in comparison with conventional wet digestion method. The accuracy of the method was tested by comparing the obtained results with that of conventional wet digestion method.      

A method for trace element determination of marine periphyton communities on discs of float glass (without sample preparation) using total-reflection X-ray fluorescence spectrometry

A quick method for trace element determination of marine periphyton communities on soda float glass discs is presented. After addition of an internal standard, the community is measured by total-reflection X-ray fluorescence (TXRF) spectrometry. No sample preparation is required except a gentle wash with distilled water. The soda glass disc on which the periphyton community grows is used directly as the sample reflector in TXRF. The method was evaluated by the analysis of a certified reference material of plankton (CRM 414) and by comparison to a wet digestion method. Recovery rates for 13 and 130 μg-samples of CRM 414 are reasonable: between 0.6 and 1.4 for the elements K, Ca, Mn, Fe, Ni, Cu, Zn, As, Rb and Sr. Relative standard deviations for 130 μg-samples are 10% or less for most of these elements. In the comparison to wet digestion, natural periphyton samples were used and the two methods showed a good agreement.The different steps used in the quantification, such as accounting for the contribution from the glass to the TXRF spectrum, and the calculation of the sample mass from the spectrum, are described. It is shown that complicating factors, such as the required water wash and the influence of an inhomogeneous spatial distribution of the periphyton on the glass disc, do not adversely affect the quantification.