Abstract:
An automated headspace gas-chromatographic method has been developed for the determination of acetone in the milk, blood and urine of dairy cows. Five ml samples were saturated with 2g of sodium chloride and equilibrated for 30 min at 90°C in a Hewlett-Packard HP 19395A automatic headspace sampler. The headspace volatiles were transferred without splitting to a 25m x 0,3mm x 0,4µm Carbowax column in a Shimadzu GC 9A gas chromatograph, operating isothermally at 50°C. The coefficients of variation for the determination of acetone were 1,5-4,4% for urine, 10,0-24,9% for milk and 2,0-19,6% for blood. The detection limits were 0,0055mg/100ml for milk, 0,0072mg/100ml for blood and 0,0080mg/100ml for urine. The analysis time of 5min per sample provided an adequate rate of throughput for routine monitoring.
