Matrix-assisted laser desorption/ionization high-resolution mass spectrometry for high-throughput analysis of androgenic steroid adulteration in traditional Chinese medicine based on d0/d5-Girard's reagent P labeling

Abstract

The illegally adulteration of traditional Chinese medicine with androgenic steroids exposes consumers to multiple health risks. Therefore, it is very important to establish an accurate detection method. The current study presents a stable isotope labeling matrix-assisted laser desorption/ionization high-resolution mass spectrometry (SIL-MALDI-HRMS) method for high-throughput quantitative analysis of androgenic steroid adulteration. A pair of isotope labeling reagents (d0/d5-Girard's reagent P, d0/d5-GP) were employed to label steroids prior to MALDI-HRMS detection. The signal intensity was significantly improved, and the signal fluctuations were compensated by employing d5-GP labeled analytes as the internal standards. The limits of quantification (LOQs) of four steroids (nandrolone, testosterone, methyltestosterone, and testosterone propionate) were in the ranges of 0.18–0.48 μg/g. The calibration curves were obtained with acceptable linearities (R2 > 0.99). The relative recoveries ranged from 87.9% to 118.1%, and the intra-day and inter-day relative standard deviations (RSDs) were all less than 13.4%, which were satisfactory for quantitative analysis. The potential of the GP labeling strategy to improve the MALDI detection sensitivity was further demonstrated by the successful detection of cinnamaldehyde and 2′-methoxycinnamaldehyde in cinnamon-containing samples. Compared with the reported methods, the developed method proved to be high-throughput, highly selective, and accurate for androgenic steroids analysis in complex samples with good sensitivity.