Volatile semi-quantitative determination

HS-SPME is a very useful tool in polymer analysis and can be applied for absolute and semi-quantitative determination of the volatile content in polymers, for degradation studies, in the assessment of polymer durabihty, for screening tests and for quality control of recycled materials. For quantitative determination of volatiles in polymers, SPME can be combined with multiple headspace extraction to remove the matrix effects. If the hnearity of the MHS-SPME plot has been verified, the number of extractions can be reduced to two, which considerably reduces the total analysis time. Advantages of MHS-SPME compared to MAE are its higher sensitivity, the small sample amount required, solvent free nature and if an autosampler is used a low demand of labor time. In addition, if the matrix effects are absent, the recovery will always be 100%. This is valuable compared to other techniques for extracting volatiles in polymers in which the recovery should be calculated from the extraction of spiked samples, which are very difficult to produce in the case of polymeric materials. 

Sen, N.P. and C. Dalpe A simple thin-layer chromatographic technique for the semi-quantitative determination of volatile nitrosamines in alcoholic beverages Analyst 97 (1972) 216. 

In the field of environmental analysis, thermal extraction is proposed by an EPA method for the quantitative analysis of semi-volatile compounds from solid sample materials. The US EPA method 8275 is a thermal extraction capillary GC-MS procedure for the rapid and quantitative determination of targeted PCBs and PAHs (polynuclear aromatic hydrocarbons) in soils, sludges and solid wastes. This method requires extraction temperatures of 340 C for 3 min for the quantitative desorption of the PCBs (EPA, 1996). 

Care must be taken over the quantification of inorganic flame retardants, since some of them (e.g., antimony trioxide) can react with the organic flame retardant present, or break down to produce volatile products, under quantitative ashing conditions, and during analysis by thermal techniques such as TGA. A good initial approach is a semi-quantitative elemental analysis by XRF, to see which types are present. Accurate quantifications can then be obtained by precise elemental determinations. 

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