Determination of 2,3 - butanedione in air by pre-column derivatization - gas chromatography

Objective To establish a method for the determination of 2,3-Butanedione in the air of workplace by pre–column derivatization - gas chromatography.Methods BUT in the air of workplace was collected at a flow rate of 0.2 L/min for 15min through 10 ml of 0.01% phosphoric acid aqueous solution filled in a porous glass plate absorption tube. The absorption solution was derivatized with o-phenylenediamine for 60 min, extracted with methylene chloride, and dehydrated with anhydrous sodium sulfate，and then separated by HP-5 capillary column (30 m×0.32 mm, 0.25 μm), and detected by nitrogen phosphorus detector(NPD). The retention time was used for qualitative analysis and the pesk area was used for quantitative analysis.Results It showed that BUT in phosphoric acid aqueous solution could be stored for at least 10 d in the refrigerator at 4 ℃. There was a linear relationship within the determination range of 0.1 mg/L ~1.0 mg/L, the linear correlation coefficient was 0.999 5.The sampling absorption efficiency was 94.0% ~ 98.8%. The average spiked recoveries was 98.0%~107.3% , the intra batch precision was 2.0%~8.2%, and the inter batch precision was 7.1%~8.1%.The detection limit of the method was 0.000 39 mg/L(LOD,S/N=3), and the quantification limit of the method was 0.001 4 mg/L (LOQ, S/N=10). The minimum detection concentration was 0.001 3 mg/m3, and the minimum quantification concentration was 0.004 7 mg/m3(based on V=3.0L).Conclusion The method has high sensitivity, good accuracy and simple operation.It can be used for the determination of BUT in the air of workplace.