Multi-mycotoxin analysis method using liquid chromatography with tandem mass spectrometry and fluorescence detection in Indian medicinal herbs: Development and validation.

While medicinal plants are in high demand worldwide for their therapeutic properties, they can constitute a health concern to consumers when contaminated with mycotoxins. The unavailability of standardised methods for multiclass mycotoxin analysis to assess health risks has thus been realised. This study reports a simple, robust and precise method to estimate nine regulated mycotoxins in a range of Indian medicinal plant matrices including giloy (Tinospora cordifolia), ashwagandha (Withania somnifera), safed musli (Chlorophytum borivilianum), satavari (Asparagus racemosus) and tulsi (Ocimum sanctum). The sample preparation method involved extraction of homogenised matrices (12.5 g) using methanol:water (8:2, 100 mL) followed by cleanup through a multi-mycotoxin immunoaffinity column (IAC), which significantly reduced matrix interferences. The method was initially developed and validated using liquid chromatography tandem mass spectrometry (LC-MS/MS) for the simultaneous analysis of aflatoxins (B1, B2, G1, G2), ochratoxin A, zearalenone, deoxynivalenol, T-2 and HT-2 toxin. Later, it was validated using LC-fluorescence (LC-FLD) for aflatoxins, ochratoxin A and zearalenone. The optimised sample preparation protocol and analytical method provided acceptable results. Compared to LC-FLD, it was possible to attain a lower limit of quantification (LOQ) with LC-MS/MS for all the tested analytes except aflatoxins. However, LOQs of both instruments were lower than the maximum limits (MLs), with recoveries ranging between 71 and 110% and precision (RSD) of ≤10% across matrices. Despite matrix-induced signal suppressions in LC-MS/MS analysis, the matrix-matched calibrations corrected all recoveries. Considering its accuracy, reliability, robustness and time-effectiveness, this method is recommended for regulatory testing purposes.

High Throughput Residue Analysis of Indaziflam and its Metabolites in Palm Oil Using Liquid Chromatography-Tandem Mass Spectrometry.

BACKGROUND: Indaziflam (IND) is a herbicide that is used in palm oil plantations for broad spectrum management of weeds. Until now, no validated method has been available for residue estimation of this herbicide in palm oil products. OBJECTIVE: In this study, we report a rapid method for the residue analysis of IND and its metabolites, viz., IND-carboxylic acid, diaminotriazine, and triazine indanone in a wide range of palm oil matrices using liquid chromatography-tandem mass spectrometry (LC-MS/MS). METHOD: The optimized sample preparation workflows included two options: (1) acetonitrile extraction (QuEChERS workflow), followed by freezing at -80°C and (2) acetonitrile extraction, followed by cleanup through a C18 solid phase extraction (SPE) cartridge. The optimized LC runtime was 7 min. All these analytes were estimated by LC-MS/MS multiple reaction monitoring. RESULTS: Both sample preparation methods provided similar method performance and acceptable results. The limit of quantification (LOQ) of IND, IND-carboxylic acid, and triazine indanone was 0.001 mg/kg. For diaminotriazine, the LOQ was 0.005 mg/kg. The method accuracy and precision complied with the SANTE/12682/2019 guidelines of analytical quality control. CONCLUSIONS: The potentiality of the method lies in a high throughput analysis of IND and its metabolites in a single chromatographic run with high selectivity and sensitivity. Considering its fit-for-purpose performance, the method can be implemented in regulatory testing of IND residues in a wide range of palm oil matrices that are consumed and traded worldwide. HIGHLIGHTS: This work has provided a validated method for simultaneous residue analysis of indaziflam and its metabolites in crude palm oil and its derived matrices with high sensitivity, selectivity, and throughput.

Direct Analysis of Glyphosate, Glufosinate, and Their Metabolites in Palm Oil Using Liquid Chromatography with Tandem Mass Spectrometry.

BACKGROUND: Glyphosate and glufosinate are broad-spectrum herbicides which are frequently used in palm oil plantations for weed control. Metabolites of these herbicides are known to have environmental and food safety implications. As there is no validated method for multiresidue testing of these herbicides and their metabolites in palm oil products, a new method was needed for the purpose of regulatory analysis. OBJECTIVE: In this study, we endeavored to develop a rapid method for multiresidue analysis of glyphosate (+aminomethylphosphonic acid) and glufosinate (+3-methylphosphinicopropionic acid and N-acetyl-glufosinate) in refined and crude palm oil matrices using liquid chromatography (LC) tandem mass spectrometry (MS/MS). METHOD: The optimized sample preparation workflow included extraction of refined or crude palm oil (10 g) with acidified water (0.1 M HCl), cleanup by phase separation with dichloromethane, and analysis by LC-MS/MS with multiple reaction monitoring. RESULTS: The use of a Torus-DEA LC column ensured simultaneous analysis of these compounds within a runtime of 10 min. The LOQ of these analytes was 0.01 mg/kg, except that of aminomethylphosphonic acid which was 0.02 mg/kg. The method sensitivity complied with the national maximum residue limits of Malaysia and the European Union. Also, the method selectivity, sensitivity, accuracy, and precision were aligned with the SANTE/12682/2019 guidelines of analytical quality control. CONCLUSIONS: The potentiality of the optimized method lies in a high throughput direct analysis of glyphosate and glufosinate with their metabolites in a single chromatographic run. The method is fit for purpose for regulatory testing of these residues in a broad range of palm oil matrices. HIGHLIGHTS: The study reports for the first time a validated method for simultaneous analysis of glyphosate, glufosinate, and their metabolites in a range of palm oil products. The method did not require a derivatization step and provided a high throughput analysis of these compounds with satisfactory selectivity, sensitivity, accuracy, and precision.