P-containing compounds

StL Pseudevernia furfuracea (L.) Zopf Lit Dembitsky et al. 1991a, 1992a 

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The thermionic or alkali flame ionization detector (FID) is a variant of the FID that has enhanced sensitivity to nitrogen (N) and phosphorous (P) containing compounds. It is essentially a hydrogen flame around a pellet of an alkali metal salt with an electric potential across the flame. Organic compounds in the air are drawn into the flame and ionized. The alkali metal enhances the response to N and P-containing compounds and, since many chemical agents contain N and P, it is selective for their detection. This detector is rarely used without prior separation by GC. 

P-containing compounds N-containing compounds Flame 1600 °C Plasma phosphorus compounds and nitrogen compounds 7 x 10-12... 

Protons are sometimes released by ion exchange reactions between aqueous components and living organisms or soil, whereby protons are unconfined due to cation substitution. Another natural proton source is the oxidation of S-, N-, and P-containing compounds, as well as the oxidation and hydrolysis of hydrated polyvalent metals such as Al3+, Fe2+, and Fe3+. For example,... 

Electrophilic cyclization of unsaturated P-containing compounds in synthesis of phosphorus heterocycles 86KGS291. 

Table 8 displays the results for the determination of the orthophosphate concentration from the photo-oxidation of various P-containing compounds. The molybdate solution (1.5 ml) is introduced in the reactor in order to follow the phosphomolybdate complex formation. The conversion yields are quantitative (Table 8) using irradiation time no longer than 15 min. 

The mechanism by which the sodium reacts with the phosphorus or the flame has not been established. However, a 5000/1 increase in selectivity is observed for P-containing compounds and about 50/1 for N compounds. 

The following groups of P-containing compounds were cationically polymerized 2-substituted-2-oxo-l,3,2-dioxophospholanes (ODPL) and the corresponding phos-phorinanes (ODPR), 2-substituted-l,3,2-dioxaphospholanes (DPL) and phosphori-nanes (DPR), 2-substituted-l,3,2-oxazaphospholidines (OAP) and 2-substituted-1,2-oxaphospholanes (OPL) ... 

Chemiluminescence from S- or P-containing compounds is obtained by combustion in a hydrogen-rich flame. Both the excited HPO radicals formed and the Sj dimers can emit a chemiluminescence spectrum which allows the selective detection of S (eg, at 394 nm) and P (526 nm) using suitable filters and a photomultiplier tube for signal amplification [26]. This flame photometric detector shows a non-linear realtionship between concentration and output signal in the sulfur mode which in theory should be quadratic (owing to the dimer formation). However, in practive, exponential coefficients of between 1 and 2 are found. Electronic linearization of the output signal is therefore necessary. 

Nomenclature of P-containing compounds of biochemical importance, lUPAC Bull., 66, 1977. 

Comparatively little is, known about H bonding to metal atoms, that is, types X-H—M or M-H—X, and also di-hydrogen bonding of the type M-H—H-X, where X=C,N,0 etc. [46,47]. Examples of P-containing compounds with M-H bonding are probably [48]. 

Listed below are miscellaneous examples used in this work and found elsewhere. See also Table 1.3 for P-containing compounds, Table 10.7 for amino acids, Table 10.15 for bases, nucleosides and nucleotides and Table 14.4 for symbols in use for analytical techniques. Symbols in commercial use for branded products are mostly excluded from all these tables. Symbols for the elements are also excluded. While some symbols and abbreviations appear to be here to stay, it should be remembered that the use of some of them can be very subject to fashion or personal choice. 

The optimized detector gas flow rates are different for N and P detection and also from that of the FID. Formation of CH radicals is suppressed in the NPD. The NPD is a selective detector for N- and P-containing compounds and the MD is about lOpgN and 5 pg P. Other detector characteristics can be found in Table 2.4. The NPD is used, for example, for pesticide determination in food and environmental applications. 

Nitrogen phosphorus detector A GC detector selective to N- and P-containing compounds similar in design to an FID and includes an alkdi salt. 

Use Only for CN and P-containing compounds. Plant protection agents. Chemical warfare gases, explosives. Plmrmaceuticals. 

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