Evaluation of matrix effects in the analysis of volatile organic compounds in whole blood with solid‐phase microextraction

Abstract

The complexity and matrix variability of biological samples requires an accurate evaluation of matrix effects. The dilution of the biological sample is the simplest way to reduce or avoid the matrix effect. In the present study, a set of volatile organic compounds with different volatilities was used to assess the effect of the dilution of blood samples on the extraction efficiency by headspace solid-phase microextraction. It was found that there was a significant matrix effect but that this effect differs significantly depending on the volatility of the compound. A 1:2 (blood/water) dilution was enough to allow quantitative recoveries of those compounds with boiling points <100°C. For compounds with boiling points between 100 and 150°C, the matrix effect was stronger and a 1:5 dilution was required. The dilution of blood samples proved to be inefficient for quantitative recovery of compounds with boiling points >150°C. A 1:5 dilution of the sample allowed detection limits in the range of nanogram per liter to be obtained. This was sufficient to detect the main volatile compounds present in blood and contamination after exposure.

Development of a solid phase microextraction method for the determination of nicotine in dried mushrooms

“…Therefore, direct immersion becomes ineffective in such matrices and headspace sampling mode is recommended for minimizing interfering background in the analysis. 25 The following parameters that may influence the extraction process were evaluated and optimized: fiber coating, sample amount, extraction temperature, extraction time, desorption time and salt addition. The optimized method was validated by determining the acceptable linearity, accuracy, precision, and detection limit.…”

Direct immersion solid‐phase microextraction with gas chromatography and mass spectrometry for the determination of specific biomarkers of human sweat in melted snow

“…Since real samples are melted snow that potentially differs from pure water, we considered the possibility of matrix effect during analysis. An accepted method for evaluating matrix effect uses isotopically labeled internal standard calibration method . Unfortunately, isotopically labeled HMHA and/or 3MSH are not available.…”

Simultaneous measurement of methyl tert‐butyl ether and tert‐butyl alcohol in human serum by headspace solid‐phase microextraction gas chromatography–mass spectrometry

“…The simplest method to reduce matrix effects is dilution of the blood, which would increase detection limits, while there are no common dilution factors. A 1:2 dilution (blood-water) was sufficient to allow quantitative recoveries of the Volatile Organic Compounds (VOCs) with boiling points <100°C (Alonso et al, 2013). A 1:2 dilution (blood-water) was sufficient to allow quantitative recoveries of the Volatile Organic Compounds (VOCs) with boiling points <100°C (Alonso et al, 2013).…”

“…The blood should be diluted 5-fold to attain quantitative recoveries and 3-fold to obtain quantitative recoveries of the strong volatile compounds (Alonso et al, 2012). A 1:2 dilution (blood-water) was sufficient to allow quantitative recoveries of the Volatile Organic Compounds (VOCs) with boiling points <100°C (Alonso et al, 2013). In this study, the serum allowed quantitative recoveries without dilution, which may have been due to the low boiling points of the two analytes, the high salt concentration of the extract solution or the lower protein content in the serum, which would benefit the evaporation of the analytes.…”