Pesticide contamination in food as a potential health risk is a growing public concern. The determinations of cationic quaternary amine polar pesticides are challenging due to their similar chemistries and similar masses and mass fragments. For example, Thermo Scientific Dionex™ IonPac™ CS21-Fast-4μm cation-exchange column was designed to resolve diquat and paraquat. This technical note provides the IC-MS conditions for twelve of the fifteen analytes. Three analytes, 1,2,4-triazole, difenzoquat, and propamocarb, are unsuitable using the Dionex IonPac CS21-Fast-4μm column for IC-MS analysis.

Worldwide food safety concerns have risen dramatically as the number of food contamination incidents and product recalls has increased. Every food analysis starts with sample preparation, which is widely accepted as one of the most critical steps of LC/MS. Increased demand for higher throughput, accuracy and lower matrix interference from food analysis laboratories has made sample preparation the largest bottleneck. Turbulent flow chromatography technology can eliminate the need for lengthy offline sample preparation steps, thereby eliminating these disadvantages.

We developed a broad, generic, automated LC-MS/MS method for screening multi-class antibiotics in honey.

The use of LC-MS/MS for screening was described in a validated multi-residue screening method to monitor 58 antibiotics in milk.

Thermo Scientific Dionex ICS-3000 system with PAD is used to run the USP Compendial Method for the assay of streptomycin sulfate. Key performance parameters, including precision in determining streptomycin purity, limits of detection, linearity, and ruggedness, are shown to be consistent with normal method validation requirement. HPAE-PAD technology is demonstrated here for streptomycin A purity analysis and its feasibility for determinations in a fermentation broth. Finally, streptomycin A purity per the requirements of the ICH for new drug substances is evaluated.