Comprehensive tropane alkaloids analysis and retrospective screening of contaminants in honey samples using liquid chromatography-high resolution mass spectrometry (Orbitrap).

A wide-scope analytical method was developed and validated for the determination of tropane alkaloids (TAs) in honey samples. A simple and fast extraction procedure, using a mixture of methanol/water/formic acid (75/25/0.4, v/v/v) as extraction solvent, followed by a clean-up with graphitized black carbon (GBC) and magnesium sulphate was optimized, and compounds were analysed by liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS-Orbitrap). Validation of the proposed method provided adequate linearity (R2 > 0.99), trueness (recoveries 71-120%) and precision (relative standard deviation, RSD ≤ 20.1%), with limits of quantitation (LOQs) at 20 µg/kg (except anisodamine and scopolamine at 40 µg/kg) and a significant matrix effect (≤-50%). Nineteen honey samples were analysed, but only one was positive, containing 27 µg/kg of scopolamine. Additionally, a post-targeted screening was performed, and 47% of samples were contaminated with different herbicides, insecticides and veterinary drugs. Therefore, the proposed analytical method is a powerful tool for both targeted TAs and post-targeted contaminant analyses.

Determination of Calystegines in Several Tomato Varieties Based on GC-Q-Orbitrap Analysis and Their Classification by ANOVA.

In this study, several calystegines (A3, A5, B1, B2, B3, B4, and C1) were determined in tomato. A simple extraction followed by a derivatization step with silylating agents was performed prior to their analysis by gas chromatography coupled to high resolution mass spectrometry (GC-HRMS-Q-Orbitrap), which allowed the monitoring of several ions at accurate mass. The validation of the method has provided suitable values of linearity, trueness (73.7-120.0%), and precision (≤20.0%, except for calystegines B3 and B4 at 0.5 mg/kg). The limit of quantitation was set at 0.5 mg/kg for all analytes. The validated method was successfully applied to the analysis of nine different tomato varieties, and calystegines A3, A5, B2, and C1 were found at concentrations ranging between 0.65 mg/kg (C1) and 12.47 mg/kg (B2). Tomato varieties were classified according to their calystegines content by applying an analysis of variance (ANOVA).

Analysis of calystegines in tomato-based products by liquid chromatography-Orbitrap mass spectrometry.

Taking into account the high consumption of tomato and tomato-based products, a study of the occurrence of 7 nortropane alkaloids (calystegines A3, A5, B1, B2, B3, B4 and C1) in this type of matrix has been performed. For that purpose, a simple and fast solid-liquid extraction with methanol/water (50/50, v/v) has been developed, and then liquid chromatography, using a HILIC-A as stationary phase, coupled to high resolution mass spectrometry (LC-HRMS-Orbitrap) has been used for their determination. The developed method was validated and recoveries ranged from 96 to 121%, and relative standard deviations lower than or equal to 16% were obtained. Limits of quantification (LOQ) were established at 0.1 (B4), 0.25 (B3) and 0.5 (A3, A5, B1, B2 and C1) mg/kg. Twelve different samples were analyzed, comprising 4 crushed tomatoes, 4 fried tomatoes and 4 jam tomatoes. Calystegines A3 and B2 were identified in all the analyzed samples, while calystegine B3 was determined in all the fried tomatoes as well as in two crushed tomatoes and one jam tomato at concentrations ranging from 0.4 mg/kg (calystegine B2) to 19.0 mg/kg (calystegine A3). Although calystegine A5 was also detected in all the samples, only 3 of them gave concentrations higher than LOQ. Additionally, calystegine B1 was found in one jam tomato at 1.9 mg/kg.

Analytical methods, occurrence and trends of tropane alkaloids and calystegines: An update.

In the last years, the interest in secondary metabolites from plants has been growing, and even more if they have or would have medical applications, as it happens with tropane alkaloids and calystegines. Therefore, the number of analytical methods for the analysis of these compounds has been increasing. In this review, the extraction methods as well as the chromatographic separation and detection techniques based on mass spectrometry to determine tropane alkaloids and calystegines in plant raw material and food have been described. Finally, a summary of the natural occurrence of tropane alkaloids and calystegines in the studied matrices, as well as their accidental presence in food, is presented, highlighting current and future determination trends.

Simultaneous analysis of tropane alkaloids in teas and herbal teas by liquid chromatography coupled to high-resolution mass spectrometry (Orbitrap).

A new method has been developed for the simultaneous determination of 13 tropane alkaloids in tea and herbal teas using high-performance liquid chromatography coupled to an Exactive-Orbitrap analyzer. A mixture of methanol, water, and formic acid was used for the extraction of the target compounds followed by a solid-phase extraction step. The validated method provided recoveries from 75 to 128% with intra- and interday precision lower than or equal to 24% (except for apoatropine). Limits of quantification ranged from 5 to 20 µg/kg. Eleven tea and herbal tea samples and two contaminated samples with Datura stramonium seeds were analyzed. Tropane alkaloids were detected in six samples with concentrations from 5 (apoatropine) to 4340 µg/kg (sum of physoperuvine, pseudotropine, and tropine), whereas concentrations from 5 (apoatropine) to 1725 µg/kg (sum of physoperuvine, pseudotropine, and tropine) were found in the contaminated samples.