Beware of Pseudo Matrix-Matched Standard Calibration Curve due to Matrix Effect on Sulfonamide Residue in Honey

Abstract

Honey was a particular matrix with a variety of composition and origin, which lead to different degree of matrix effect on analytes. As a rule, the matrix-matched calibration curve from blank honey was adopted to quantifying analyte in a batch. This paper investigated matrix effect on sulfonamide in four honey samples by high-performance liquid chromatography hyphenated with mass spectrometry detection. The main goal was to check whether matrix-matched calibration curve obtained from a random blank honey could match the real samples in character within current recommended acceptance criteria. It was found that analyte recovery from true matrix-matched standard calibration curve ranged 87.7-117.3%, whereas recovery from surrogate matrix-matched calibration curves gave a very wide range from 54.3 to 150.2%, far beyond the acceptance criteria. So it was perhaps not feasible to use a surrogated blank sample to prepare matrix-matched calibration curve for quantifying analyte, particularly for largely diverse honey samples in a batch. To reduce error from inter-sample matrix effect, the best solution seemed to use internal standard or standard addition.