Detection, group-specific

Desoxyadenosine oligonucleotides la 76 Desoxycholic acid la 334 11-Desoxycorticosterone la 221 lb 346 Detection, group-specific la 4,7 -, substance specific la 4,7 Detection of lipqjhilic substances la 43 -, biological-physiologically la4,6,7, 9,109... 

An example of the use of polyacrylamide gels in an ief system in combination with immun obi otting is given in Reference 40 where this method is used to detect low quantities of group specific component (GC) subtypes. Another example of polyacrylamide in combination with ief is given in Reference 41 where the technique is used as a screening tool for inheritance of a certain polymorphic protein. 

In spite of numerous advances in the field of detection there are not and never have been any genuinely substance-specific chemical detection reactions. This means that, unlike the spectrometric methods, the methods of detection normally employed in chromatography cannot be employed for an unequivocal identification of compounds, they can only provide more or less definite indications for the characterization of the separated substances. Universal reagents are usually employed for a first analysis of the separation of samples of unknowns. This is then followed by the use of group-specific reagents. The more individual the pieces of information that can be provided from various sources for a presumed substance the more certainly is its presence indicated. However, all this evidence remains indicative it is not a confirmation of identity. 

The determination of bismuth activity as an indicator of non-ionic surfactants also suffers from interference in environmental samples. Substance group specific methods also failed to detect different types of fluorine-containing anionic, cationic and non-ionic surfactants. Already marginal modifications in the precursor surfactant due to primary degradation or advanced metabolisation implicated their lack of detection [45]. 

As shown in Figure 6.13b, Q1 and Q3 are both scanning from low to high mass but with a fixed mass difference that corresponds to the mass of the neutral molecule lost during CID. This can be especially useful when analysing the same class of compounds or for group-specific detection. 

Niessen, M. L., and Vogel, R. F. (1998). Group specific PCR-detection of potential trichothecene-producing Fusarium-spedes in pure cultures and cereal samples. Syst. Appl. Microbiol. 21, 618-631. 

The purpose of this chapter is to describe the analytical methods that are available for detecting and/or measuring and monitoring 2,3-benzofuran in environmental media and in biological samples. The intent is not to provide an exhaustive list of analytical methods that could be used to detect and quantify 2,3-benzofuran. Rather, the intention is to identify well-established methods that are used as the standard methods of analysis. No methods approved by federal agencies or other groups specifically for detection of 2,3-benzofuran were located. 

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