Organic compounds, analysis

Mass spectrometry. 2. Organic compounds Analysis. I. Modugno, Francesca. II. Title. QD272.S6C63 2009 702.8 8 dc22... 

Pleil JD, Lindstrom AB. 1995. Collection of a single alveolar exhaled breath for volatile organic compounds analysis. Am J Ind Med 28(1) 109-121. 

St-Germain F, Mamer O, Brunet J, et al. 1995. Volatile organic compound analysis by an inertial spray extraction interface coupled to an ion trap mass spctrometer. Anal Chem 67 4536-4541. 

Pleil, J. D and A. B. Lindstrom, Collection of a Single Alveolar Exhaled Breath for Volatile Organic Compounds Analysis, Am. J. Indust. Med., 28, 109-121 (1995). 

Accuracy, organic compound analysis, methods needed, 288-289 Acetylperoxy radicals, conversion to H02, 311... 

Organic compounds-Analysis. 2. Environmental chemistry. I. Boethling, Robert S. II. Mackay, Donald. QD271.H3186 2000 547. 3—dc21... 

Another tool that enables us to evaluate analytical accuracy of organic analyses is surrogate standards. These are compounds that do not naturally occur in the environment and that are similar in chemical nature and behavior to target analytes. In organic compound analysis, known amounts of surrogate standards are added to each sample prior to extraction. The comparison of surrogate standard recoveries to laboratory control limits permits the laboratory to monitor the efficacy of extraction and to measure the accuracy of analysis for each individual sample. 

Series—Sample preparation and cleanup methods for metal and organic compound analysis... 

Series—Miscellaneous tests (aggregate organic compound analysis, anions, coliform, radiochemistry)... 

Prior to the preparation of field and laboratory QC samples for organic compound analysis, sample preparation personnel amend them with surrogate standards to monitor the efficacy of extraction for each sample matrix. Surrogate standards are organic compounds that are similar in chemical behavior to the target analytes and that are not expected to be present in samples. 

In organic compound analysis, the instrument response is expressed as a response factor (RF), which is the ratio of the concentration (or the mass) of the analyte in a standard to the area of the chromatographic peak. Conversely, a calibration factor (CF) is the ratio of the peak area to the concentration (or the mass) of the analyte. Equation 1, Appendix 22, shows the calculation of RF and CF. In trace element and inorganic compound analyses, the calibration curve is usually defined with a linear regression equation, and response (calibration) factors are not used for quantitation. 

Laboratory QC data are classified as batch QC data and individual sample QC data. For all types of analysis, batch QC data originate from laboratory blanks, laboratory control samples, matrix spikes, and laboratory duplicates. Individual sample QC data in organic compound analysis are obtained from surrogate and internal standard recoveries. Matrix interference detection techniques (serial dilution tests, postdigestion spike additions, and MSA tests) are the source for individual sample QC checks in trace element analysis. (Chapter 4.4.4.5 addresses the trace element matrix interference detection techniques and the associated acceptance criteria.)... 

Laboratories subsample two aliquots of a field sample from the same container and treat them as two separate samples. Typically, laboratory duplicates are prepared and analyzed with every 10 samples in trace element and inorganic analyses. This allows laboratories to calculate the RPD between the two results as a measure of analytical precision. Laboratory duplicates are rarely used in organic compound analysis. 

Surrogate standard recovery measures analytical accuracy for each individual sample. Approved methods for organic compound analysis usually recommend the surrogate standard selection. Similar to target analytes, multipoint calibration curves are prepared for surrogate standards. 

The importance of surrogate standard recovery in evaluating data quality cannot be overemphasized. Laboratories evaluate the efficacy of extraction of each individual sample based on the surrogate standard recovery. If batch QC checks are acceptable, but the individual sample surrogate standard recovery is not, the validity of sample results is questionable. Results of organic compound analysis performed without surrogate standards cannot be considered definitive. 

Similar to LCS recoveries, surrogate standard recoveries should be monitored by the laboratory and plotted as control charts. The EPA recommends the use of in-house laboratory control limits for surrogate standards recoveries for all organic compound analyses (EPA, 1996a). The exception is the CLP SOW, which specifies these limits for soil and water analysis. Unless affected by matrix interferences, surrogate standard recoveries normally have relatively narrow control limits, 65-135 percent for most organic compound analysis. (Many laboratories, however, default to arbitrary limits of 50-150 percent for GC analyses, instead of using statistical control limits.)... 

Data Evaluation Checklist—Organic Compound Analysis... 

Add 0.008% of sodium thiosulfate (Na2S203) to all samples collected for organic compound analysis with the exception of SW-846 Methods 8081, 8082, and 8141, if residual chlorine is present. 

Microbial Volatile Organic Compounds as Indicators for Hidden Mold Growth, Selection of Microbial Volatile Organic Compounds, Analysis, Evaluation... 

Swallow, K.C., N.S. Shifrin, and PJ. Doherty. 1988. Hazardous organic compound analysis. Environ. Sci. Technol. 22 136-142. 

G. LeBlanc, A Review of ERA Sample Preparation Techniques for Organic Compound Analysis of Liquid and Solid Samples, LC GC, 19(11) (2001) 1120. 

Letellier, M. and Budzinski, H., Microwave assisted extraction of organic compounds. Analysis, 27, 259-271, 1999. 

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