Capillary atomic emission spectroscopy

M. Mazurek, Z. Witkiewicz, S. Popiel andM. Sli-wakowski, Capillary gas chromatography-atomic emission spectroscopy-mass spectrometry analysis of sulfur mustard and transformation products in a block recovered from Baltic sea, J. Chromatogr. A, 919, 133-145 (2001). 

Pedersen-Bjergaard, St, Semb, S. I., Vedde, J., Brevik, E. M., and Greibrokk, T., Environmental screening by capillary gas chromatography combined with mass spectrometry and atomic emission spectroscopy, Chemosphere, 32, 1103-1115, 1996. 

Capillary electrophoresis and atomic emission spectroscopy (CE-AES) Capillary electrophoresis (CE) is a rapidly emerging tool for many routine cHnical and pharmaceutical appHcations. Due to the high separation efficiency of the CE, this combination aUows the speciation of elements even in rather complex matrices such as human serum. A challenge for this hyphenation is the interface compatible with the low flow rate of CE, which can be as litde as a few nL min, compared with a typical sample introduction rate of 1 mL min into the fCP. Most interfaces reported in the Hterature contact the CE via a suitable Pt contact in a sheath buffer flow, which is mixed with the CE effluent, e. g. in a PEEK tee. As the total flow is significantly increased by the make-up flow, a conventional nebuliser can be used for sample introduction. 

In the past, the most common method of analysis of small anions has been ion-exchange chromatography. For cations, the preferred techniques have been atomic absorption spectroscopy and inductively coupled plasma emission spectroscopy. Recently, however, capillary electrophoretic methods have begun to compete with these traditional methods for small ion analysis. Several major reasons for adoption of electrophoretic methods have been recognized lower equipment costs, smaller sample size requirements, much greater speed, and better resolution. 

Sulfur-containing components exist in gasoline-range hydrocarbons and can be identified with a gas chromatographic capillary colunm coupled with either a sulfur chemiluminescence detector or an atomic emission detector (AED) (ASTM D-5623). The most widely specified method for total sulfur content uses X-ray spectrometry (ASTM D-2622), and other methods that use ultraviolet fluorescence spectroscopy (ASTM D-5453) and/or hydrogenolysis and colorimetry (ASTM D-4045) are also apphcable, particularly when the sulfur level is low. 

GC can achieve the highest resolution of the essential oils, but there are some significant limitations with regards to preparative scale separations. Typically, as the sample capacity is increased, the resolution of the chromatographic separation is reduced. On a lab scale, equipment is available that permits 24-hour automated and unattended separations, however, the recovery yield and sample resolution are still problematic [57]. Capillary column GC has become so routine for essential oil analysis that one rarely finds a lab without that capability. A multitude of detectors exist for GC thermal conductivity (TCD), flame ionization (FID), flame photometric (FPD), thermionic specific (TSD), photoionization (PID), electron capture (ECD), atomic emission (AED), mass spectrometry (MS), and infrared spectroscopy (FTIR) [58,59]. The TCD is used primarily with preparative-GC (packed column) because it is... 

Most of the commonly used methods of inorganic analysis of plastics, including inductively coupled plasma emission spectroscopy, atomic absorption spectroscopy, ionic chromatography, and capillary electrophoresis, require that the samples for analyses be introduced preferably as solutions with low viscosity and minimal salt content. 

The selective detectors discussed in the previous sections often do not provide enough information to elucidate with 100% probability the nature of the eluting solutes. For this reason, data with selective detectors can be erratic. The future in this respect definitely belongs to the spectroscopic detectors that allow. selective recognition of the separated compounds. Today, the hyphenated techniques CGC-mass spectroscopy (CGC-MS), CGC-Fourier transform infrared spectroscopy (CGC-FTIR), and CGC-atomic emission detection (CGC - AED) are the most powerful analytical techniques available. They provide sensitive and selective quantitation of target compounds and structural elucidation or identification of unknowns. The applicability and ease of use of the hyphenated techniques were greatly increased by the introduction of fused silica wall coaled open tubular columns. The main reason for this is that because of the low flows of capillary columns, no special interfaces are required and columns are connected directly to the different spectrometers. The introduction of relatively inexpensive benchtop hyphenated systems has enabled many laboratories to acquire such instrumentation, which in turn has expanded their applicability ever further. 

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