Fused silica capillary column GC/MS for the analysis of priority pollutants

Abstract

SummaryOperational characteristics have been determined for fused silica capillary column (FSCC) GC/MS as applied to "extractable" priority pollutants. Chromatographic data show excellent relative retention time (RRT) intralaboratory precision and interlaboratory accuracy when multiple internal standards are employed. Potential chromatographic problems, such as column overload and "double peaking", are addressed. Response factor relative standard deviations (RSD) at 50 ng for most of the extractable priority pollutants over the long term indicated precise determination (i.e. RSD generally < l0"/0). Linearity was demonstrated over two orders of magnitude for FSCC GC/MS analysis of compounds with relatively low and highRF(response factor) values. Potential quantitative problems, such as saturation, are discussed. For certain aromatic priority pollutants interlaboratory RF agreement was obsewed. This was noted as perhaps the most important property of FSCC GC/MS analysis when the multiple internal standard approtach is utilized. Determinations of extractable priority pollutants are directly compared for packed column GUMS and FSCC GC/MS analysis of separate and composited extracts. For !six extracts analyzed in triplicate, the latter configuration was shown to produce more consistent results. In view of the superior analysis logistics of composite extract FSCC GC/MS analysis, this approach was established as the preferred method for the analysis of priority pollutants classified as extractable.

Strategies for compound identification and quantification using fused silica capillary column GC/MS

“…SD RRT windows reflect a precision equivalent to the optimum achievable with the single 2,2'-difluorobiphenyl internal standard.This trend is also similarto that generated from short-term precision data [5] for avery limited number of compound pairs.…”

“…This is evident from the small +3 SD windows near 540 seconds where the internal standard is eluted.The RRTwindowwidths increase in both directions from the internal standard retention time and become equivalent to absolute retention time window widths at both ends of the chromatogram. A similar trend has been noted for short-term retention time windows [5] although it was far less apparent than it is for long-term windows.…”

“…In GC/MS studies the accuracy with which retention times can be predicted determines the quantity of data which must be processed while looking for a particular spectral pattern, and has an impact upon both data reduction time and the potential for compound misidentification. When retention time uncertainty requires the use of wider retention time "windows", the likelihood of misidentification increases [5], due to existence of isomers with similar spectraand to the random chance that an unrelated component may produce a spectrum similar to the target compound spectrum. With these considerations in mind, the long term retention time precision characteristics of the test mixture compounds were used to identify the approach by which retention time predictions are optimized, and hence the narrowest search windows can be used.…”

“…Taking advantage of its applicability to a wide range of compounds, FSCC GClMS has been proposed for environmental analysis methods in which acidic and baselneutral extracts are combined and analyzed in a single run [ l ] . Subsequent investigations have indicated an even broader scope of combinedfraction analyses [2,3], high degrees of short term analytical precision [4,5] and excellent interlaboratory agreement [6]. Throughout this period of rapid technological advance, most efforts have, of necessity, been directed toward establishing short term operating characteristics.Although this is understandable, it does not go far enough to include such important applications as routine determinations of chemical pollutants [6].…”

General applications of fused silica capillary column (FSCC) chromatography to the analysis of non‐priority pollutant organics in environmental samples

“…Suggested revisions to these protocols have included the use of fused silica open tubular columns in place of the conventional wide bore glass packed columns. Recently investigators have accomplished analysis of the complete listing of priority pollutant organic extractables using a single fused silica capillary GC/MS run in place of several runs with conventional glass-packed columns [3,4]. The analysis of combined sample extracts on fused silica columns has in fact proven to be more expedient and more sensitive than conventional column chromatography while simultaneously providing a significant increase in data quality .…”