Determination of origin through analysis of pesticide residues in Korean and Chinese red pepper powder using GC-MS/MS

The recent increase in imports of Chinese red pepper powder has led to significant issues concerning the mixing of Korean and Chinese red pepper powders, and mislabelling, posing a major threat to consumer trust. This study provides a robust method for verifying the origin of red peppers through pesticide residue analysis using gas chromatography–tandem mass spectrometry (GC–MS/MS). Multivariate statistical analysis techniques were applied to the multi-component pesticide residue data to visually distinguish the characteristic patterns of Chinese and Korean red pepper powders. The sophisticated partial least squares discriminant analysis yielded a high model quality, with R2 = 0.856 and Q2 = 0.774. A heatmap visualisation grouped the pesticides contributing to the differentiation between each group. In the linear discriminant analysis, the distance difference between the medians of each group was 133.5, confirming significant class discrimination capability. Through measurement uncertainty analysis, the relative standard uncertainty of the calibration curve was confirmed to be at the 21-24% level. This study demonstrates that GC-MS/MS can also be applied as a method for determining the origin of different agricultural products using pesticide residues.