Atomic quartz furnace

QFAAS Quartz furnace atomic absorption (2) Segmented charge-coupled... 

Szpunar, J., Ceulemans, M., Schmitt, VO., Adams, F.C. and Lobinski, R. (1996) Microwave-accelerated speciation analysis for butyltin compounds in sediments and biomaterials by large volume injection capillary gas chromatography quartz furnace atomic absorption spectrometry. Anal. Chim. Acta, 332, 225-232. 

Figure 6.1 Bar-graph of MeHg in CRM 580. The results correspond to six replicate determinations as performed by different laboratories using various methods. MEANS indicates the mean of laboratory means with 95% confidence interval. Abbreviations-. CVAAS, cold vapour atomic absorption spectrometry CVAFS, cold vapour atomic fluorescence spectrometry ECD, electron capture detection GC, gas chromatography HPLC, high-performance liquid chromatography ICPMS, inductively coupled plasma mass spectrometry MIP, microwave induced plasma atomic emission spectrometry QFAAS, quartz furnace atomic absorption spectrometry SFE, supercritical fluid extraction.

U.S. Environmental Protection Agency. 2001. Method 1632. Chemical speciation of arsenic in water and tissue by hydride generation quartz furnace atomic absorption spectrometry. 

Donard, O.F.X., S. Rapsomanikis, and J.H. Weber. 1986. Speciation of inorganic tin and alkyltin compounds by atomic absorption spectrometry using electrothermal quartz furnace after hydride generation. Anal. Chem. 58 772-777. 

For clcmcnt-speciPc detection in GC, a number of dedicated spectrometric detection techniques can be used, for example, quartz furnace AAS or atomic Bu-orescence spectrometry (AFS) for Hg, or microwave-induced plasma atomic emission spectrometry (MIP-AES) for Pb or Sn. However, ICP-MS is virtually the only technique capable of coping, in the on-line mode, with the trace element concentrations in liquid chromatography (LC) and capillary electrophoresis (CE) efBuents. The femtogram level absolute LoDs may still turn out to be insufficient if an element present at the nanogram per milliliter level splits into a number of species, or when the actual amount of sample analyzed is limited to some nanoliters as in the case of CE or nanoBow HPLC. The isotope spcciPcity of ICP-MS offers a still underexploited potential for tracer studies and for improved accuracy via isotope dilution analysis. 

Ricci and coworkers have described a highly sensitive, automated technique for the determination of MMAA, DMAA, p-aminophenyl arsonate, arsenite and arsenate. This procedure is based on ion-chromatography on a Dionex column, with 0.0024 M NaHC03/0.0019 M NajCOj/O.OOl M Na2B407 eluent, when all the compounds except arsenite and dimethyl arsinite are separated effectively. For separation of the last two, a lower ionic strength eluent (0.005 M Na2B407) can be used in a separate analysis. The detection system utilizes a continuous arsine generation system followed by heated quartz furnace atomization and atomic absorption spectrometry. Detection limits of less than 10 ng/ml were obtained for each species. 

QFAAS, quartz-furnace atomic absorption spectroscopy FPD, flame photometric detection MS, mass spectrometry ICP-MS, inductively coupled plasma-mass spectrometry. 

A selenium speciation study was carried out by Seby etal. (1997) on a seleniferous soil using hydride generation quartz furnace atomic absorption spectrometry (HG-QFAAS) method and after alkaline extraction. The speciation was performed in order to identify and determine inorganic and organic selenium forms. 

Andreae [712] used four different detectors in his investigations the electron capture detector (for the methylarsines), the quartz cuvette atomic absorption detector (for arsenic and antimony species), the graphite furnace atomic... 

Willie et al. [17] used the hydride generation graphite furnace atomic absorption spectrometry technique to determine selenium in saline estuary waters and sea waters. A Pyrex cell was used to generate selenium hydride which was carried to a quartz tube and then a preheated furnace operated at 400 °C. Pyrolytic graphite tubes were used. Selenium could be determined down to 20 ng/1. No interference was found due to, iron copper, nickel, or arsenic. 

The recommended procedure for the determination of arsenic and antimony involves the addition of 1 g of potassium iodide and 1 g of ascorbic acid to a sample of 20 ml of concentrated hydrochloric acid. This solution should be kept at room temperature for at least five hours before initiation of the programmed MH 5-1 hydride generation system, i.e., before addition of ice-cold 10% sodium borohydride and 5% sodium hydroxide. In the hydride generation technique the evolved metal hydrides are decomposed in a heated quartz cell prior to determination by atomic absorption spectrometry. The hydride method offers improved sensitivity and lower detection limits compared to graphite furnace atomic absorption spectrometry. However, the most important advantage of hydride-generating techniques is the prevention of matrix interference, which is usually very important in the 200 nm area. 

The vapor can be atomized in inert gas-hydrogen diffusion flames, in narrow-bore quartz tubes electrically heated or heated over an air-acetylene flame, and in plasmas. Additionally, the atomizer can act as a vapor preconcentration medium just before atomizing. This is what happens in graphite furnace atomizers (in situ trapping) or on silver or gold wires for direct amalgamation of mercury. 

Further developments are expected due to the nonspecificity of the ECD detector. The possibility of coelution with other compounds has triggered the interest in interfacing chromatography systems to Hg-specific detectors. The volatility of zerovalent Hg and the ease of thermal decomposition of alkyl-Hg compounds have allowed for a wide variety of solutions that use cold vapor (CV) atomic absorption spectrometry (AAS) in a fused silica quartz cell. Significant improvements were observed when the atomization and detection were performed directly in the fused silica furnace at 780°C using an 02 flow and after considerable reduction of the transfer lines [26],... 

---