生物样品及中药中汞、砷的测定

建立了一种梯度升压微波消解样品 ,氢化物发生原子荧光光度法测定生物样品及中药中的汞、砷的方法。在优化实验条件下 ,生物样品中Hg回收率为97.3 %～99.1 % ,As回收率为99.4 %～105.7% ;含朱砂、雄黄中药 ,Hg、As平均回收率分别为(104.1±5.3) % ,(94.6±1.8) %。该法具有操作简便、快速、准确、灵敏、重复性好等优点。     

微波消解试样-火焰原子吸收光谱法测定原油和渣油中铁、镍和铜

采用微波消解技术消解原油和渣油样品,研究了微波消解-火焰原子吸收光谱法测定原油和渣油中铁、镍和铜的方法。考察了最佳样品用量、酸用量、微波消解时间、消解压力、消解功率,确定了微波消解原油和渣油的最佳程序。此法样品损失少,酸用量少,降低了环境污染,所用时间缩短了3.5倍。测定结果与灰化法结果一致,铁、镍和铜的相对误差分别为1.6%,1.4%和1.6%。该方法简便、快速、准确,是一种绿色环保的分析方法。     

微波消解-氢化物发生原子荧光法

采用微波消解样品，氢化物发生原子荧光法，测定了牡蛎壳中微量砷的含量；通过试验，优化了微波消解的条件和仪器的最佳工作参数；结果表明该法具有快速、简便、准确等特点，砷的检出限为0.05μg/L，线性范围0-32μg/L；样品分析结果的相对标准偏差为0.44%(n=6)，加标回收率98％。     

微波消解-分光光度法测定石油焦中的硅

重点研究了微波消解石油焦样品的方法,详细考察了微波消解时样品的最佳用量、消解压力、消解功率、消解时间,建立了最佳微波消解程序：在样品处理中也采用了常规溶样方法,并分别用两种样品处理方法测定石油焦中的硅。结果表明两种方法测定结果基本吻合,样品测定的RSD小于3．85％,加标回收率在97％～103％之间,但微波消解法的溶样速度是常规法的10倍。实验结果表明,微波消解分光光度法测定石油焦中的硅是一种快速、准确且无环境污染的绿色环保方法,具有一定的实用价值。     

微波消解技术在农业样品分析中的应用

利用光纤压力自控密闭微波消解系统对土壤和植株样品中重金属元素测定的影响进行了研究，确立了样品消解试剂、微波消解每件及样品预处理方法。结果表明，该方法与常压湿法消解相比，具有样品消解时间短、消解试剂用量少、样品污染小等特点，是准确可靠的土壤及植株样品中重金属元素检测样品消解处理方法。     

“新型高压湿法消解方法”在铅检测中的应用

在食品中和生物材料的微量元素检测中,应用新型高压湿法消解前处理方法,快速、高效地消解各类样品。综合各种因素,对普通食品、生物样品,最佳消解条件为120℃时,3h,样品质量（g）／浓HNO3量（mL）／H2O2（mL）为1：3：1。由回收率试验可知,铅的回收率在95．8％－104．5％,其准确度完全能够满足食品或生物材料中微量金融分析的要求。由于高压湿法消解比干法灰化方法具有快速、高效、准确度高,且消解温度低（低于150℃）,无污染,节省能源等优点,将该法引入食品和生物材料检测工作,可大大提高工作效率,而且可以提高检测准确度。     

水中总磷量的密闭微波增压消解快速测定

研究了用聚四氟乙烯密封带密封容器，利用微波加热技术，在较高的温度和压力下消解样品，快速测定环境水样中总磷量的方法；讨论了微波功率、微波消解时间、酸度等因素对测定结果的影响，与标准方法对照，经t检验法及F检验法检验，测定结果没有显著性差异，多次加标回收率在98％－103％之间，相对标准偏差≤1．3％，结果令人满意；该法具有操作简便、快速、不污染环境、宜于大批量样品的测定、便于推广普及等优点，可用于其它样品的分析测定。     

微波消解ICP-OES法快速测定雪莲果中的微量元素

微波消解雪莲果样品后,等离子体发射光谱仪一次进样曝光快速测定了钾、钠、钙、镁、铜、铁、锌、锰、钼、镍10种微量元素。结果表明,雪莲果中富含钾、钙、镁等元素。该法一次消解样品、多元素同时测定,准确、快速、精密度高,符合分析要求。     

微波消解衍生化气相色谱-质谱法测定鲨鱼软骨中的脂肪酸

 研究了用微波技术消解衍生化气相色谱 质谱法 (GC MS)快速测定鲨鱼软骨中脂肪酸的分析方法。用正交设计试验优化消解衍生化条件 ,以盐酸 甲醇 (体积比为 1∶4)体系作消解衍生化溶液 ,在 60 0W微波功率作用下加热 4min进行样品的前处理 ,将样品的消解、脂肪酸的衍生化及脂肪酸甲酯的萃取融于一体。方法具有灵敏度高、省时、省试剂、操作方便等特点。该法适用于大批量固体样品中脂肪酸的测定。     

半消解-石墨炉原子吸收光谱法测定土壤中镉

土壤样品常用的消解方法有全量消解和半消解两种方法,全量消解用氢氟酸除去硅酸盐,使用器皿要求较高,而且要赶尽氢氟酸,防止残余的氢氟酸腐蚀玻璃器皿,半消解法消解土壤样品,避免使用氢氟酸,消解比较简单,使用器皿要求较低.有关用半消解法测定土壤中重金属元素[1-3]]的报道很少.镉元素有化学致癌作用[4],检测方法主要有分光光度法、原子吸收光谱法、荧光光谱法、电感耦合等离子体质谱法、极谱法、中子活化分析法[5]等方法.石墨炉原子吸收光谱法由于灵敏度高,样品用量少,分析速度快等特点而得到广泛应用.本法采用盐酸一硝酸一高氯酸消解土壤样品,石墨炉原子吸收光谱法测定镉的含量,使用传统的湿法消解,操作简单方便,消解完全,结果准确.     

Single vessel procedure for acid-vapour partial digestion in a focused microwave: Fe and Co determination in biological samples by ETAAS

A single vessel procedure using a focused microwave oven is proposed for biological sample preparation with nitric acid vapour under atmospheric pressure. A laboratory-made PTFE support vessel equipped with four cups that received the samples was adapted to fit on the microwave glass vessel. Biological samples (30 mg) were directly weighed into these PTFE cups followed by the addition of 150 microliters of water or H2O2. The mixture was exposed to acid vapour stemming from 15 ml of concentrated HNO3 placed in the bottom of the glass vessel. The acid vapour was formed at 115 degrees C and brought about the Co and Fe extraction in 10 and 60 min, respectively. The resulting suspension was diluted with 0.14 mol l-1 HNO3 to a final volume of 1.0 ml, shaken and centrifuged. The supernatant was analysed by electrothermal atomic absorption spectrometry (ETAAS) by placing the cups directly in the autosampler of the spectrometer. This system minimised contamination, and reagent and time consumption and was suitable for Co and Fe determination in biological materials. The accuracy of the proposed method was assessed by using certified reference materials and by comparison with the closed vessel microwave as a comparative technique. Cobalt and Fe recovery was around 82-99%. As an additional advantage, up to 6 samples can be simultaneously prepared in each vessel, thereby improving the sample throughput from 6 to 24, when a 6-cavity focused microwave is used.     

Determination of 94Nb in radioactive waste using ion exchange chromatography

This paper describes a rapid method of ⁹⁴Nb pre-concentration, separation and purification by using cation and anion exchange resins. The method is suitable for analyzing highly contaminated radioactive waste samples in a relatively short time and high decontamination factors. The use and effectiveness of the method was successfully tested by analysis of samples from nuclear reactor parts such as control rod drive shaft, shielding cassettes, neutron in-core measurement channels (KNI), pressure vessel construction material and fuel cassette construction material samples.     

Direct ICP-MS determination of trace and ultratrace elements in geological materials after decomposition in a microwave oven. Part II. Quantitation of Ba, Cs, Ga, Hf, In, Mo, Nb, Pb, Rb, Sn, Sr, Ta and Tl

A new method has been developed for the rapid determination of traces of Ba, Cs, Ga, Hf, In, Mo, Nb, Pb, Rb, Sn, Sr, Ta and Tl in silicate rocks and lake, stream and river sediments. The method involved dissolution of samples in a microwave oven by heating in a pressure decomposition Teflon vessel with a mixture of HF + HNO₃ + HCl + H₃BO₃ + EDTA followed by direct multielement determination using inductively coupled plasma-mass spectrometry (ICP/MS). The method is faster than conventional dissolution of samples by open vessel acid digestion and fusion and determination by instrumental methods. The accuracy and precision of the developed method were tested by replicate analyses of a number of international geochemical reference samples of established trace element contents. Satisfactory correlation with the “recommended” or “consensus” values was found and recoveries were in most cases 95–100%. New values for Ga, In, Nb and Tl in several international geochemical reference materials are first reported in this paper.     

微波溶解光度法测定茶叶中痕量锗

采用微波加热和双层聚四氟乙烯密闭容器，以HNO3－HClO4为消解试剂、MgO为外层吸收剂，用CCl4萃取，光度法快速测定茶叶中痕量锗。研究了消化茶叶的最佳条件。萃取锗的最佳酸度及其它影响因素。该方法具有选择性高，成本低等特点，其精密度和准确度令人满意。     

A simple decomposition and chelating resin separation for the determination of heavy metals in silicates by atomic absorption spectrometry

A simple method for the determination of copper, nickel, zinc, and cadmium in silicate rock samples is reported. Silicates are decomposed with hydrofluoric acid and aqua regia in a sealed Teflon vessel. After centrifugation and addition of malonic acid, the supernatant liquid is passed through a small column of Chelex 100. The metals are eluted with 2 M nitric acid, and determined by atomic absorption spectrometry. The method is rapid, simple, and free from contamination. The results obtained for 14 standard reference rock samples (USGS, GSJ, and CSRM) agree with literature data; the recovery, reproducibility, and accuracy of the proposed method are satisfactory.     

微波加热快速测定腐植酸总量

利用微波加热技术，在密闭容器内通过压力浸提、消解试样、能大大加快分析速度，本实验测定了不同煤样中的腐植酸总量，讨论了功率、时间、酸度等因素对分析结果的影响，并与标准方法相对照，用ｔ－检验法及Ｆ－检验法检验，没有明显差异，结果令人满意，该法具有省时、省力、经济、不污染环境，宜于批量分析，便于普及推广等优点。     

Demethylation of methylmercury during inorganic mercury determination by the magos cold vapor atomic absorption technique

Previous animal experiments suggested that the Magos cold vapor atomic absorption spectroscopic (CVAAS) method might overestimate the concentrations of inorganic mercury (I-Hg) in the presence of methylmercury (MeHg). In the present study it is shown that this error is due to a fast degradation of MeHg during the formation of the analytical signal. For brain samples, about 5% of the total amount of MeHg in the reaction vessel is degraded to I-Hg. Speciation of Hg in aqueous solution of MeHg chloride, after purification with ionexchange chromatography using the Magos method, showed that about 9% was I-Hg. Analysis by NMR of MeHg chloride and MeHg hydroxide showed that less than 1% was in the form of I-Hg. The absolute magnitude of the error in the CVAAS method is dependent on the amounts of SnCl₂ and MeHg in the reaction vessel; however, the ratio of I-Hg to total (T-Hg) is shown to be independent of the amount of MeHg (25.5–255 ng as Hg) in the reaction vessel. A procedure for corrections is proposed, based on the results from these studies and empirical data from speciation analyses of brain tissue from MeHg-exposed rats and rabbits.     

Examination of the different procedural steps in the determination of organotin compounds in water samples

Previous animal experiments suggested that the Magos cold vapor atomic absorption spectroscopic (CVAAS) method might overestimate the concentrations of inorganic mercury (I-Hg) in the presence of methylmercury (MeHg). In the present study it is shown that this error is due to a fast degradation of MeHg during the formation of the analytical signal. For brain samples, about 5% of the total amount of MeHg in the reaction vessel is degraded to I-Hg. Speciation of Hg in aqueous solution of MeHg chloride, after purification with ionexchange chromatography using the Magos method, showed that about 9% was I-Hg. Analysis by NMR of MeHg chloride and MeHg hydroxide showed that less than 1% was in the form of I-Hg. The absolute magnitude of the error in the CVAAS method is dependent on the amounts of SnCl₂ and MeHg in the reaction vessel; however, the ratio of I-Hg to total (T-Hg) is shown to be independent of the amount of MeHg (25.5–255 ng as Hg) in the reaction vessel. A procedure for corrections is proposed, based on the results from these studies and empirical data from speciation analyses of brain tissue from MeHg-exposed rats and rabbits.     

Acid digestion of geological and environmental samples using open-vessel focused microwave digestion

The application of open vessel focused microwave acid digestion is described for the preparation of geological and environmental samples for analysis using inductively coupled plasma-mass spectrometry (ICP-MS). The method is compared to conventional closed-vessel high pressure methods which are limited in the use of HF to break down silicates. Open-vessel acid digestion more conveniently enables the use of HF to remove Si from geological and plant samples as volatile SiF4, as well as evaporation-to-dryness and sequential acid addition during the procedure. Rock reference materials (G-2 granite, MRG-1 gabbros, SY-2 syenite, JA-1 andesite, and JB-2 and SRM-688 basalts) and plant reference materials (BCR and IAEA lichens, peach leaves, apple leaves, Durham wheat flour, and pine needles) were digested with results comparable to conventional hotplate digestion. The microwave digestion method gave poor results for granitic samples containing refractory minerals, however fusion was the preferred method of preparation for these samples. Sample preparation time was reduced from several days, using conventional hotplate digestion method, to one hour per sample using our microwave method.     

Electrochemical immunoassay: an ultrasensitive method.

Hydrodynamic electrochemical techniques such as liquid chromatography and flow injection analysis with electrochemical detection are very effective for the rapid determination of the enzyme-generated product in enzyme immunoassays. The authors have used this detection method in various assay formats using both alkaline phosphatase and glucose-6-phosphate dehydrogenase as labels. Assays for digoxin will be used illustratively. Recently, the authors have used 70 mL microcapillary hematocrit tubes as the immunoassay reaction vessel and alkaline phosphatase as the labeling enzyme. The assay, complete in 30 min, had a detection limit of 5,6 x 10 -20 moles of IgG in serum. The linear range was four orders of magnitude. This low detection limit is due to a combination of the favorable geometry of the reaction vessel and the suppression of nonspecific adsorption by the addition of ion-pairing blocking agents. Even lower detectable amounts should be achievable with smaller reaction vessels. The capability for detecting such small amounts of analyte is potentially useful for the analysis of extremely small samples such as single cells and blood samples from premature infants.