Phenylarsenic compounds

A detailed study of the radiochemical reactions of phenylarsenic compounds has been published by Grossmann. Once again unable to effect isolation of all compounds, he was able, however, to get evidently reliable values for the sums of all compounds with one, two and three phenyl-arsenic bonds, respectively, as well as ionic arsenic and a further organic-soluble fraction which appeared to be a group of polymeric phenylarsenic compounds. Selected data from this work are given in Table 6. 

Table 6. Yields of various fractions in phenylarsenic compounds . Irradiation in vacuo at — 50 °C, 10— 20 h,...

On the other side of the argument, it has several times been shown that the initial existence of bonds is not a requirement for final molecule production. The experiments of Siekierska and Sokolowska were very clear in this respect. When AsClj was irradiated in degassed benzene solution, phenylarsenic compounds were found up to 22% of the As, even though ASCI3 can itself act as a scavenger in this system. The formation of As( 3 was in fact only 0.86%. 

Not many organometallic systems have been subjected to extensive thermal annealing studies— the most thorough work has been done on the phenylarsenic compounds. The earliest such study was that of Maddock and Sutin on triphenylarsine. The results are in part given in Fig. 1, from which it was concluded that the reformation progresses in the stepwise fashion ... 

Lussi-Schlatter and Brandenberger [211] have reported a method for inorganic arsenic and phenylarsenic compounds based upon gas chromatography with mass specific detection after hydride generation with headspace sampling. However, methylarsenic species were not examined. 

Since only few speciation methods for phenylarsenic compounds are available the 40... 

The extraction of phenylarsenic compounds from soil was first described by Schoene (1993). 

The increase of extraction yields through several extraction steps has been described in literature (Bowadt and Hawthorne, 1995). In opposite to this Wenclawiak and Krah received no significant increase of extraction yields for inorganic and methylated arsenic compounds which could be confirmed for phenylarsenic compounds in the realized investigation (Wenclawiak and Krah, 1995). 

Headspace and thermal desorption are thermal extraction methods which can be directly connected to gas chromatography and do not need additional sample preparation. Usually both methods are applied for the determination of volatile compounds in air and water. Only few applications are known for the direct treatment of soil samples. The investigations for analysis of phenylarsenic compounds were carried out with an Headspace Sampler HS40 (Perkin-Elmer Inc.) and a Thermal desorption system TDS 2 (Gerstel GmbH, Germany). 

Figure 15. Phenylarsenic compounds identified by high resolution-MS.

Suitable methods for speciation analysis of phenylarsenic compounds in soil and plant samples have been developed. In spite of the considerable contamination of the soil, the arsenic content of terrestrial plants is apparently modest. 

Haas, R. Krippendorf, A. Determination of chemical warfare agents in soil and material samples Gas chromatographic analysis of phenylarsenic compounds (Stemutators). Environ. Sci. Pollut. Res. 1997, 4 (3), 123-124. 

DPAA in humans has also been investigated. Kinoshita et al. [44] tested different columns and mobile phases for the detection of phenylarsenic compounds in urine from patients, mice and environmental samples of groundwater... 

Figure 4.12 Chromatograms of five standard phenylarsenic compounds (PDMAO, PMAA, PAA, DPMAO and DPAA) separated on three different stationary phases, (a) C4 column, (b) CN column and (c) NH2 column. The C4 column gave a more efficient separation and was used in further studies [44]. Kinoshita K. et al. Urine analysis of patients exposed to phenylarsenic compunds via accidental pollution, Journal of Chromatography B, 867, 2008 with permission from Elsevier...

Kinoshita, K., Shikino, O., Seto, Y., Kaise, T. (2008) Urine analysis of patients exposed to phenylarsenic compounds via accidental pollution./. Chromatogr. B, 867 (2), 88-179. 

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