Organic acids as the modifier to determine Zn, Cd, Tl and Pb in soil by slurry sampling electrothermal vaporization inductively-coupled plasma mass spectrometry

Raspberry-Like Bismuth Oxychloride on Mesoporous Siliceous Support for Sensitive Electrochemical Stripping Analysis of Cadmium

BiOCl-SiO₂ KIT-6 composite materials with raspberry-like structures are facilely prepared under hydrothermal conditions. The mesoporous siliceous support of SiO₂ KIT-6-incorporated BiOCl with enlarged yet refined surface morphology characterized by physiochemical methods exhibits an improved electrochemical performance. A sensitive electrochemical detection method of cadmium concentration using square wave anodic stripping voltammetry was developed based on BiOCl-SiO₂ KIT-6 composite-modified glassy carbon electrodes, which displayed wide linear ranges of 0.5 to 10 μg/L and 10 to 300 μg/L and a detection limit of 65 ng/L. The sensitive, versatile and eco-friendly sensor was successfully applied for the determination of cadmium-spiked human blood samples.

Diagnostic Assay of Toxic Zinc in an Ex vivo Cell Using Voltammetry

Voltammetric detection of the toxic Zn ion was investigated using a fluorine-doped graphite pencil electrode (FPE). It is notable from the study that pencils were used as reference and working electrodes. In all the experiments, a clean seawater electrolyte solution was used to yield good results. The analytical working range was attained to 10 μgL(-1). The optimized voltammetric condition was examined to maximize the effect of the detection of trace Zn. The developed sensor was applied to an earthworm's tissue cell. It was found that the methods can be applicable to in vivo fluid or agriculture soil and plant science.

Hollow-fiber liquid-phase microextraction prior to low-temperature electrothermal vaporization ICP-MS for trace element analysis in environmental and biological samples

A new method of hollow-fiber liquid-phase microextraction (HF-LPME) prior to electrothermal vaporization (ETV) inductively coupled plasma mass spectrometry (ICP-MS) determination of trace Cu, Zn, Pd, Cd, Hg, Pb and Bi, based on gaseous compounds introduction into the plasma as their diethyldithiocarbmate (DDTC) chelates, was developed. The use of the reagent DDTC as chemical modifier could not only enhance the analytical signals, but also decrease the vaporization temperature. At a temperature of 1300 degrees C, trace Cu, Zn, Pd, Cd, Hg, Pb and Bi can be vaporized completely into the ICP. The factors affecting the formation of the chelates and their vaporization behaviors were investigated in detail, and the microextraction conditions were optimized. Under the optimized conditions, the detection limits of the proposed method were 12.4, 28.7, 7.9, 4.5, 3.3, 4.8 and 1.6 pg ml(-1) for Cu, Zn, Pd, Cd, Hg, Pb and Bi, respectively. Enrichment factors of 305, 284, 24, 29, 20, 73 and 43 could be achieved within 15 min of extraction time, and the relative standard deviations (RSDs) for the seven determinations of 0.5 ng ml(-1) of target analytes were 8.8, 6.9, 7.1, 9.4, 10.2, 6.1 and 10.8%, respectively. The newly developed method has been applied to the determination of trace Cu, Zn, Pd, Cd, Hg, Pb and Bi in environmental water and human serum samples, and the recoveries for the spiked samples were in the range of 88-116%. In order to validate this method, two certified reference materials, GBW08501 peach leaves and GBW(E)080040 seawater, were analyzed, and the determined values were in good agreement with the certified values.

Slurry sampling electrothermal vaporization inductively coupled plasma mass spectrometry for the determination of As and Se in soil and sludge

Slurry sampling electrothermal vaporization (ETV) inductively coupled plasma mass spectrometry (ICP-MS) has been applied to determine As and Se in soil and sludge samples. The influences of instrument operating conditions and slurry preparation on the ion signals were reported. Pd and ascorbic acid were used as mixed modifiers to enhance the ion signals. The effectiveness of ETV sample introduction technique for alleviating various spectral interferences in ICP-MS analysis has been demonstrated. This method has been applied to determine As and Se in NIST SRM 2709 San Joaquin soil reference material and NIST SRM 2781 domestic sludge reference material and a farmland soil sample collected locally. Since the sensitivities of As and Se in slurry solution and aqueous solution were different, analyte addition technique was used to determine As and Se in these samples. The As and Se analysis results of the reference materials agreed with the certified values. The precision between sample replicates was better than 5% for all determinations. The method detection limit estimated from analyte addition curves was about 0.03 and 0.02 microg g(-1) for As and Se, respectively, in original soil and sludge samples.

Electrothermal vaporization dynamic reaction cell inductively coupled plasma mass spectrometry for the determination of Fe, Co, Ni, Cu, and Zn in biological samples

Slurry sampling electrothermal vaporization dynamic reaction cell inductively coupled plasma mass spectrometry (ETV-DRC-ICP-MS) has been applied to determine Fe, Co, Ni, Cu, and Zn in biological samples. The influences of instrument operating conditions and slurry preparation on the ion signals were reported. Pd was used as the modifier. The effectiveness of the ETV sample introduction technique and dynamic reaction cell in alleviating various spectral interferences in ICP-MS analysis has been demonstrated. This method has been applied to determine Fe, Co, Ni, Cu, and Zn in NIST SRM 1573a tomato leaves reference material and NRCC DORM-2 dogfish muscle reference material and also real samples such as a tea and a swordfish sample purchased locally. Since the sensitivities of the elements studied in slurry and aqueous solution were different, an analyte addition technique was used for the determinations. The analytical results of the reference materials agreed with the certified values. The precision between sample replicates was better than 6% for all determinations. The method detection limit estimated from analyte addition curves was 0.01, 0.006, 0.007, 0.004, and 0.006 microg g(-1) for Fe, Co, Ni, Cu, and Zn, respectively, in the original biological samples.

Determination of Cadmium, Chromium, Copper and Lead in Sediments and Soil Samples by Electrothermal Atomic Absorption Spectrometry Using Zirconium Containing Chemical Modifiers

A method for direct determination of cadmium, chromium, copper and lead in sediments and soil samples by electrothermal atomic absorption spectrometry using Zr, Ir, etylenediamine acetic acid (EDTA), Zr + EDTA, Ir + EDTA, Zr + Ir and Zr + Ir + EDTA as chemical modifiers in 0.5% (v/v) Triton X-100 plus 0.2% (v/v) nitric acid mixture used as diluent was developed. The effects of mass and mass ratio of modifiers on analytes in sample solutions were studied. The optimum masses and mass ratios of modifiers: 20 microg of Zr, 4 microg of Ir, 100 microg of EDTA and 20 microg of Zr + 4 microg of Ir + 100 microg of EDTA, were used to enhance the analyte signals. Pyrolysis and atomization temperatures, atomization and background absorption profiles, characteristic masses, and detection limits of analytes in samples were compared in the presence or absence of a modifier. The detection limits and characteristic masses of analytes in a 0.5% (m/v) dissolved sample (dilution factor of 200 ml g(-1)) obtained with Zr + Ir + EDTA are 8.0 ng g(-1) and 1.2 pg for Cd, 61 ng g(-1) and 4.3 pg for Cr, 32 ng g(-1) and 23 pg for Cu, and 3.4 ng g(-1) and 19 pg for Pb, respectively. The Zr + Ir + EDTA modifier mixture was found to be preferable for the determination of analytes in sediment and soil-certified and standard reference materials. Depending on the sample type, the percent recoveries of analytes were increased from 81 to 103% by using the proposed modifier mixture; the results obtained are in good agreement with the certified values.

Simultaneous Derivative Spectrophotometric Determination of Zinc and Cadmium with 2-(5-Bromo-2-pyridylazo)-5-diethyl-aminophenol in the Presence of Cetylpyridinium Chloride

A selective and sensitive derivative photometric method has been developed for the determination of trace amounts of Zn2+ with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol in the presence of cetylpyridinium chloride, a cationic surfactant. The molar-absorption coefficient and analytical sensitivity of the 1:2 complex at 554 nm are 1.19 x 10(5) L mol(-1) cm(-1) and 0.56 ng mL(-1), respectively. The detection limit is 1.96 x 10(-2) ng mL(-1) and Beer's law is valid in the 0.02-0.66 microg mL(-1) range of Zn2+. The developed derivative procedure, using the zero-crossing measurement approach, is applied for the rapid and selective simultaneous determination of Zn2+ and Cd2+ in the range of 0.06-0.66 and 0.20-1.60 microg mL(-1), respectively. Complex matrices, including reference materials, environmental and biological samples and synthetic mixtures, have been successfully analyzed for trace amounts of the two metal ions.

Current awareness. Current literature in mass spectrometry

In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of mass spectrometry. Each bibliography is divided into 11 sections: 1 Books, Reviews & Symposia; 2 Instrumental Techniques & Methods; 3 Gas Phase Ion Chemistry; 4 Biology/Biochemistry: Amino Acids, Peptides & Proteins; Carbohydrates; Lipids; Nucleic Acids; 5 Pharmacology/Toxicology; 6 Natural Products; 7 Analysis of Organic Compounds; 8 Analysis of Inorganics/Organometallics; 9 Surface Analysis; 10 Environmental Analysis; 11 Elemental Analysis. Within each section, articles are listed in alphabetical order with respect to author (3 Weeks journals - Search completed at 7th. Mar. 2001)