Fast temperature programming in routine analysis of multiple pesticide residues in food matrices

Flash gas chromatographic (GC) analysis of 15 organophosphorus pesticides c ommonly occurring in food crops was performed using the Thermedics Detectio n EZ Flash upgrade kit installed in the oven of a HP 5890 Series II Plus ga s chromatograph. The temperature program and splitless time period were the main parameters to be optimized. In the first set of experiments wheat mat rix-matched standards were analyzed both by: (i) the flash GC technique (re sistive heating of a 5 m capillary column), and (ii) the conventional GC te chnique (moderate oven temperature programming of a 30 m capillary column). Using the flash GC technique, the analysis time was reduced by a factor of more than 10 compared to the conventional CC technique. Dramatically impro ved detectability of analytes was achieved due to much narrower peak widths . The flash GC technique was compared with another approach to faster CC an alysis employing a 5 m column and fast temperature programming with a conve ntional GC oven. In comparison with this alternative, in the case of flash GC significantly better retention time repeatability was observed. The othe r superiority of resistive heating is very rapid cooling down (i.e., equili bration to the initial conditions) which contributes to the increased sampl e throughput. (C) 2001 Elsevier Science B.V. All rights reserved.