Sample Introduction In Atomic Spectrometry Research Articles

Determination of chlorate, perchlorate and bromate anions in water samples by microbore reversed-phase liquid chromatography coupled to sonic-spray ionization mass spectrometry.

Sonic-spray ionization mass spectrometry (SSI-MS) has recently been shown to provide similar mass spectra to those generated by electrospray ionization mass spectrometry for a wide range of compounds, i.e. from small inorganic species to peptides, proteins and numerous other biomolecules. However, limited information about this new ionization technique, such as sensitivity, limit of detection and quantification accuracy, has been reported. In particular, its coupling to liquid chromatography needs further development and assessment, along with the introduction of a broad range of applications. A high-efficiency glass pneumatic nebulizer, used for decades for sample introduction in atomic spectrometry, was used for the SSI-MS analysis of chlorate (ClO3- ), perchlorate (ClO4- ) and bromate (BrO3- ) anions, following their separation using reversed-phase microbore high-performance liquid chromatography and tandem mass spectrometry (MS/MS) operated in selected reaction monitoring mode. The developed and optimized microbore HPLC/SSI-MS/MS technique exhibited low limits of detection: 5.3ng L-1 for chlorate, 10ng L-1 for perchlorate and 33.7ng L-1 for bromate, and provided reliable and accurate measurements of chlorate concentrations in water samples as demonstrated when comparing it with Ion Chromatography-Conductivity Detection (IC-CD), the benchmark technique for ion quantitation. This is the first time that the use of HPLC/SSI-MS/MS has been reported for the detection and quantitation of chlorate, perchlorate and bromate in water samples. In addition, the exceptionally low LODs achieved using SSI render the technique competitive with the established and dominating electrospray ionization technique. Here, we have demonstrated that a commercially available high-efficiency glass pneumatic nebulizer can also be used, without any further modification, as an efficient gas-phase ion source. Copyright © 2017 John Wiley & Sons, Ltd.

Young scientists and sample introduction in atomic spectrometry: What lies ahead?

Young scientists and sample introduction in atomic spectrometry: What lies ahead?

Tubular electrolytic hydride generator for continuous and flow injection sample introduction in atomic absorption spectrometry

An electrolytic hydride generation system for sample introduction in atomic spectrometry is described. The system uses a tubular electrolytic flow-through cell with a concentric arrangement and a packed cathode made of vitreous carbon. The large cathode surface area (about 120 cm2) gives efficiencies in hydride production of >90% for As(III), Se(IV) and Sb(III). Samples can be introduced in both continuous and flow injection modes, because the low dead volume (390 µl) of the generator complies with the dispersion requirements of flow injection systems. The generator was coupled to a flame heated quartz tube for atomic absorption measurements. The detection limits for As, Se and Sb in aqueous solutions were 5.2, 2.5 and 1.4 ng ml−1, respectively, with relative standard deviations of 0.7–3.3%.

Insight into the interaction of the microwave radiation with droplets of interest in analytical chemistry

The idea of heating aerosols by applying a microwave field has recently been taken up again for liquid sample introduction in atomic spectrometry. Heating of the droplets can take place directly, because of microwave energy absorption by the droplets themselves, or indirectly, as a result of heat transmission from the radiated parts of the system to the droplets by conduction, convection or thermal radiation. There is some degree of discrepancy among the specialists on this subject, i.e., about the contribution of each of these mechanisms to the temperature of the aerosol. Some of them state that there is no direct coupling between the microwave radiation and the droplets, only indirect heating. However, we claim that both ways of heating occur. In this work we support our point of view on the basis of the existing bibliographical background, a theoretical analysis and our own experimental results.

A flowing electrolytic hydride generator for continuous sample introduction in atomic spectrometry

Hydride generation is a useful technique for sample introduction in atomic spectrometry. Apparatus utilizing the chemical reduction of aqueous As, Se, Sb, Te and Pb are in common use and commercially available. An alternate method of hydride generation is electrolytic reduction. This method requires fewer reagents, reducing the potential risk of sample contamination. In this study, the construction and evaluation of a new flowing electrolytic hydride generator for sample introduction in atomic spectrometry is described. The effectiveness of several possible cathode materials and electrolytes is compared. Flame atomic absorption spectrometry was used to detect As, Se and Sb in aqueous solutions after conversion to AsH3, H2Se and SbH3. Sensitivity increases of 11–18 times over pneumatic solution nebulization were realized. Also, inductively coupled plasma atomic emission spectrometry (ICP-AES) was combined with this new type of hydride generator for the detection and quantitation of As and Se in aqueous solutions. Detection limits by ICP-AES were 0.7 μg/ml and 3 μg/ml for As and Se, respectively. In addition, the effects of several possible concomitants on the production of H2Se and AsH3 were examined.

Interpreting some analytical characteristics of thermal dispersion methods used for sample introduction in atomic spectrometry

Thermal dispersion methods are used to produce a dry aerosol by heating the sample to high temperature and mixing the released product with a cold gas. The factors and conditions which severely affect the aerosol formation and transport with the use of electrothermal heating are treated in a tutorial form with respect to the knowledge of aerosol science. Some conclusions are also drawn on the systems in which other means of heating (e.g. lasers, sparks) are applied.