A novel technique to detect chloroform at trace levels in biological specimens and other items

Abstract

The ability to confirm chloroform at trace levels in autopsy specimens and relevant contaminated items is a challenge to the forensic toxicologist. This paper reveals how sensitive and selective headspace gas chromatography- mass spectrometric method was developed to detect chloroform at trace levels in blood in two cases in Sri Lanka. Chloroform in suspected items was extracted into methanol. Separation was performed on a 60 m x 0.32 mm capillary column GC-GASPRO. The qualitative and quantitative analysis of chloroform was performed in the scan and single ion monitoring (SIM) modes respectively using mass spectrophotometric detector. The method was validated in terms of linearity (r2 = 0.993) for the concentrations ranging from 5-100 mg/L, repeatability (RSD – 4.1 % at 10 mg/L, n= 6), limit of detection 1 mg/L and limit of quantification 3.3 mg/L. In a case of sexual assault toxicological analysis of the contents of the chemical bottle revealed the presence of chloroform at a concentration of 422 mg/L and traces of chloroform on a piece of cloth. In the case of hanging Chloroform was identified in the concentration of 72 mg/L in blood and traces were found in the empty bottle found at the scene.