Abstract
A rapid and simple GC/MS method to detect ethephon residues in apples is introduced using an internal standard and direct extraction of the analytes from the matrix at low pH with ethyl acetate. A one step derivatization procedure has been established using N-tert-butyldimethylsilyl-N-methyltrifluoracetamide (MTBSTFA) prior to GC/MS analysis performed in selected ion monitoring mode (SIM). Optimization of the derivatization and GC- parameters led to good method performance and measurement precision. Recovery experiments showed recovery rates ranging from 80.8 to 95.5% in the concentration range were investigated. The presented method provides significant improvements in laboratory safety, sample throughput and instrumentation cost compared with other methods to detect ethephon residues in apples.