| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 95573 | Forensic Science International | 2014 | 7 Pages |
•A procedure for HS-GC/FID was developed for the analysis of 11 VOCs.•The method was validated in whole blood, urine and vitreous humor.•The method proved to be selective and sensitive for small sample volumes (100 μL).•It is not necessary to apply any extraction procedure (HS injection technique).•The method developed has been applied to forensic cases.
A simple and sensitive procedure, using n-propanol as internal standard (IS), was developed and validated for the qualitative and quantitative analysis of a group of 11 volatile organic substances with different physicochemical properties (1-butanol, 2-propanol, acetaldehyde, ethyl acetate, acetone, acetonitrile, chloroform, diethyl ether, methanol, toluene and p-xylene) in whole blood, urine and vitreous humor. Samples were prepared by dilution with an aqueous solution of internal standard followed by Headspace Gas Chromatography with a Flame-ionization Detector (HS GC-FID) analysis. Chromatographic separation was performed using two capillary columns with different polarities (DB-ALC2: 30 m × 0.320 mm × 1.2 μm and DB-ALC1: 30 m × 0.320 mm × 1.8 μm), thus providing a change in the retention and elution order of volatiles. This dual column confirmation increases the specificity, since the risk of another substance co-eluting at the same time in both columns is very small. The method was linear from 5 to 1000 mg/L for toluene and p-xylene, 50–1000 mg/L for chloroform, and 50–2000 mg/L for the remaining substances, with correlation coefficients of over 0.99 for all compounds. The limits of detection (LOD) ranged 1 to 10 mg/L, while the limits of quantification (LOQ) ranged from 2 to 31 mg/L. The intra-day precision (CV < 6.4%), intermediate precision (CV < 7.0%) and accuracy (relative error ±10%) of the method were in conformity with the criteria normally accepted in bioanalytical method validation. The method developed has been applied to forensic cases, with the advantages that it uses a small sample volume and does not require any extraction procedure as it makes use of a headspace injection technique.
