A novel ISM‐SAM strategy, based on gas chromatography/mass spectrometry analysis, to compensate for matrix effects in the determination of pyruvic acid

Abstract

Rationale The matrix effect is tricky in gas chromatography/mass spectrometry (GC/MS) analyses. Although several methods have been proposed to solve this problem, the results were unsatisfactory. Even fewer studies have assessed the performance of corrective methods. Hence, our study focused on assessing several common corrective methods, and then proposed a new strategy to correct for the matrix effect in GC/MS analyses. Methods In GC/MS analyses, the internal standard method (ISM) was employed to overcome the matrix effect during the detection of pyruvic acid (PA) in serum samples from a healthy adult female. The accuracy of the ISM was evaluated by comparing it with the standard addition method (SAM). To employ the ISM‐SAM strategy, correction factors (CFs) were established by combining the ISM and the SAM based on different groups. The CFs were used to normalize data onto the results of subsequent analyses. Results When using the ISM to detect levels of PA, a serious bias is observed, thereby affecting the conclusions reached. In contrast, more reliable data can be obtained after normalizing results by undertaking the ISM‐SAM strategy. The feasibility of this strategy was verified by comparing it with the results of the SAM alone. The ISM‐SAM strategy was successfully applied to quantify the PA levels in healthy people and nephrotic syndrome patients. Conclusions Our results indicated that a false outcome was presented when only the ISM was used to adjust the data, and important information would be missed if the correction strategy was not carried out. Therefore, ISM‐SAM, as an available correction method, should be adapted to improve the reliability of research results.

Quantification of carbohydrates in human serum using gas chromatography–mass spectrometry with the stable isotope-labeled internal standard method

“…As a broad-spectrum derivatization reagent, BSTFA may cause other substances in serum to react and cause a matrix effect. [28][29][30] Most carbohydrates exist as isomeric metabolites, and the structure of the derivatized products of the isomeric metabolites is similar in the silylation reaction. We used the same parent and product ions to quantify isomeric metabolites such as mannose and galactose.…”