LC/ICP-AES

ICP is intolerant to the solvents commonly used in LC development. Consequently, most LC-ICP-AES systems have been employed with ion-exchange columns, as this separation process largely involves aqueous mobile phases that are amenable to the ICP-AES instrument. Use of acetonitrile or THF in the mobile phase has usually evoked a change in interface design to accommodate the different solvents. The advantages of LC-ICP-AES include multi-element detection and the ability to obtain real-time chromatograms. LC-ICP-AES... 

Several publications described the online combination of gas chromatography with microwave-induced plasma optical emission spectrometry or AAS for the speciation of mercury, e.g. [117,118]. The problem with this method and others such as LC-ICP-AES or GC-ICP-MS is that they require equipment and an experienced staff that are normally not available in a clinical chemistry laboratory. Therefore these highly specialized methods are not described here in detail. 

SDS-PAGE, MALDI TOP MS, 2-D Gel HPLC, GC, GC-MS GC, GC-MS HPLC, FTIR Diastase analysis GC, enzymatic assay LC, LC-MS, CE Pollen analysis AES and ICP-AES... 

The literature reports many analytical techniques used for the speciation analysis of As in multifarious matrices, including food. The usual methods are GC or LC coupled with spectroscopic or electrochemical detection [185, 248] the standard detectors are AAS, ICP AES and ICP MS [192, 246, 249]. One of the more favoured techniques for the speciation analysis of As is HG AAS coupled with... 

An inductively-coupled plasma (ICP) is an effective spectroscopic excitation source, which in combination with atomic emission spectrometry (AES) is important in inorganic elemental analysis. ICP was also considered as an ion source for MS. An ICP-MS system is a special type of atmospheric-pressure ion source, where the liquid is nebulized into an atmospheric-pressure spray chamber. The larger droplets are separated from the smaller droplets and drained to waste. The aerosol of small droplets is transported by means of argon to the torch, where the ICP is generated and sustained. The analytes are atomized, and ionization of the elements takes place. Ions are sampled through an orifice into an atmospheric-pressure-vacuum interface, similar to an atmospheric-pressure ionization system for LC-MS. LC-ICP-MS is extensively reviewed, e.g., [12]. 

EDXRF, HG-QFAAS, HG-ICP-AES, ICPMS HG-GC-QFAAS, LC-UV-ICP-AES, LC-UV-HG-QFAAS, LC-ICPMS... 

Figure 3 Instrumental methods for the determination of arsenic compounds (Abbreviations AAS, atomic absorption spectrometry APS, atomic fluorescence spectrometry CE, capillary electrophoresis GC, gas chromatography HG, hydride generation ICP-AES, inductively coupled plasma-atomic emission spectrometry ICP-MS, inductively coupled plasma-mass spectrometry INAA, instrumental neutron activation analysis LC, liquid chromatography MS, mass spectrometry).

A range of chromatographic techniques coupled to element specific detectors has been used in speciation studies to separate individual organometallic species (e.g., butyltins, arsenic species) and to separate metals bovmd to various biomolecules. The combination of a chromatographic separation with varying instrumental detection systems are commonly called coupled, hybrid, or hyphenated techniques (e.g., liquid chromatography inductively coupled plasma-mass spectrometry (LC-ICP-MS), gas chromatography-atomic absorption spectroscopy (GC-AAS)). The detection systems used in coupled techniques include MS, ICP-MS, atomic fluorescence spectrometry (AFS), AAS, ICP-atomic emission spectrometry (ICP-AES), and atomic emission detection (AED). 

A large diversity of instrumental techniques are also available to determine these elements, from those extremely simple such as volumetric, spectrophotometric, electrochemical or flame photometric ones, a second group of medium complexity, like FAAS, ICP-AES, ICP-MS, or even EASS, and a third group of greatest technological complexity which could include FIA-ETAAS-HPLC, FIA-HPLC-ICP-MS, etc. All these instrumental alternatives can also be coupled with different kind of preconcentration systems (chelating resins, matrix modifiers, LC, etc.) which allow to minimize the effect of impurities interferences, and consequently to obtain a better analytical signal. 

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. 

The USFDA stipulated a maximum level of contamination of seafood by methylmercury of 1 mg/kg [185]. Consequently, routine speciation analyses had to be implemented in laboratories monitoring the quality of food products before these could be allowed onto the consumer market. The techniques usually used for monitoring food quality are LC coupled with CV AAS or CV ICP MS [172]. The inference to be drawn from van Dael s review [185] is that advanced techniques, such as CV AAS, CV AFS, FT IR and microwave-induced plasma AES (MIP AES), and less sophisticated methods offer comparable selectivity and sensitivity for determining speciation forms of Hg in food to satisfy food quality monitoring requirements. 

Modern analytical such as infrared (IR) spectroscopy, liquid chromatography (LC), and gas-liquid chromatography (GLC) are in use for the identification of organic components, whilst the mineral constituents can be estimated by using X-ray fluorescence (XRF) spectrometry. X-ray diffraction (XRD), atomic absorption spectrometry (AAS), or inductively coupled plasma (ICP) atomic emission spectrometry (AES). 

Another group of analytical methodologies which can be used for mercury determination within aquatic samples exists, and includes a large diversity of techniques like preconcentration on coated graphite tubes and ETAAS [346,347] as well as with other matrix modifiers [348,349] atomic fluorescence spectrometry (AES) [350-352]) ICP-MS coupled with CV generation [353,354], isotope dilution [355,356], or LC [357 58] GC— FAAS coupled with reversed-phase liquid chromatography [73359360] or, the use of biological substrates for studies on metal speciation [361-363]. 

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