Toxins trace analysis

Saxitoxin has been labeled with fluorescamine, o-phthaldialdehyde (OPA) and dansyl chloride and detection limits as low as 0.1 attomole were reported for the OPA derivative of saxitoxin (26). Labeling, separation, and analysis of saxitoxin was best accomplished using fluorescamine, which produces ionic derivatives that can be separated from other fluorescently labeled marine toxins, such as tetrodotoxin and microcystin. However, the precolumn labeling methods required xM concentrations of analyte, limiting the utility of the technique for trace analysis. 

Correction of LC-MS RRFs for relative ion abundance. Equal sensitivities for parent and analogue should initially only be assumed for the total ionization. SIR or MRM techniques will be used for trace analysis of toxins. For SIR, the full-scan spectra of parent and analogue should be checked. The assumed RRF of 1.0 should be adjusted if the ions monitored differ in their relative abundances (as % of TIC) due to differences in in-source fragmentation and adduct ion formation. It is probable that the relative intensities in the MS/MS daughter ion spectra will vary between parent and analogue. A cross-calibration... 

Over 1000 articles dealing with atomic absorption are published each year making a truly comprehensive review a difficult task. What the authors have chosen to do is to discuss the recent advances in instrumentation and technique of particular interest to those persons involved in the analysis of air and water samples for trace metal toxins. 

Several potential etiologies were investigated, including infectious agents, pet-borne vectors, contaminated food, organophosphate pesticide exposure, and vinyl chloride contamination from food containers, before a link was made between the new disease and the consumption of adulterated cooking oil. Chemical analysis of the case-associated oil identified brassicasterol, a marker for rapeseed oil, trace amounts of aniline, oleyl anilide, and other fatty acid anilides and contaminants (Aldridge, 1992 Posada de la Paz et al., 1996 Ruiz-Mendez et al., 2001). The toxin or toxins appear to be stable in oil, since consumption of toxic oil one year after the main epidemic led to development of the disease. 

Biotlogical and chemical analysis of specific markers related to the pathogen/ toxin involved, so as to trace its provenance. 

There is no doubt as to the remarkable potential of the EC-MS technique for the analysis of biotoxins it represents a serious alternative to the mouse bioassay or, at least, a supplementary analytical tool for tracing an extensive toxin profile of contaminated shellfish. The current rapid developments in EC-MS methodology look promising for a close attainment of these objects however, further improvement and interlaboratory studies will be necessary. In addition, a serious problem, which does not allow, at present, this technique from becoming a generally accepted tool in regulatory analysis is the nonavailability of pure analytical standards and reference materials for most YTXs. 

Rivasseau, C., Martins, S., and Hennion, M.C., Determination of some physicochemical parameters of microcystins (cyanobacterial toxins) and trace level analysis in environmental samples using liquid chromatography, J. Chromatogr, 799, 155, 1998. 

Some of the many uses for ICP-MS include analysis of environmental samples for ppb levels of trace metals and nonmetals, the analysis of body fluids for elemental toxins such as lead and arsenic, determination of trace elements in geological samples, metals and alloys,... 

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