ANALYSIS OF CYANIDE IN BLOOD BY HEADSPACE SOLID-PHASE MICROEXTRACTION(SPME) AND CAPILLARY GAS-CHROMATOGRAPHY

Cyanide can be extracted from whole blood samples by headspace solid-p hase microextraction (SPME) with a Carbowax/divinylbenzene-coated fibe r. During heating a vial of a whole blood sample containing cyanide an d acetonitrile as internal standard (IS) at 50 degrees C in the presen ce of Na2SO4, a Carbowax/divinylbenzene-coated SPME fiber was exposed in the headspace of the vial for 45 min to allow adsorption of cyanide and IS. The fiber needle was then injected into a capillary gas chrom atography (GC) instrument equipped with nitrogen-phosphorus detection. The headspace SPME-GC with a Supel-Q PLOT fused silica capillary colu mn gave large peaks for cyanide and IS; almost no interfering peaks ap peared. Recoveries of cyanide and IS from human whole blood were 3.02- 4.06 % and 0.21 %, respectively. The calibration curve for cyanide add ed to human blood showed excellent linearity in the range of 0.04-4.0 mu g mL(-1); the detection limit was about 0.02 mu g mL(-1). The coeff icients of intra-day and inter-day variation were not greater than 7.1 and 9.2 %. Good correlation (r(2) = 0.999) was found between the pres ent SPME-GC method and the conventional microdiffusion colorimetric me thod. Data on determination of cyanide in rat blood after intraperiton eal administration are also presented.