Multicenter evaluation of ultrafiltration, dialysis, and thermal coagulation as sample pretreatment methods for the colorimetric determination of paraquat in blood and tissues

Three methods of sample pretreatment for the rapid colorimetric determination of paraquat were compared: ultrafiltration, dialysis, and thermal coagulation. Spiked autopsy blood and tissue samples were examined in parallel in Groningen and Krakow and some samples were interchanged. All three methods gave recoveries between 87 to 102%; accuracy at the 20-mg/L level was within 10% of the target value and coefficients of variation in the 10 to 60-mg/L range were between 3 to 15%. Determinations in blood and liver in a fatal case of Gramoxone poisoning showed excellent agreement. Because of its reliability, speed, and simplicity, ultrafiltration is the method of choice.     

Detection of morphine and codeine in blood samples with gas chromatography/mass spectrometry (NCI and PCI) for differentiating codeine use from use of heroin and morphine

Morphine and codeine were isolated from blood with C18 Bond Elut columns and derivatised with pentafluoropropionic anhydride (PFPA). The PFPA-derivatives were examined by means of gas chromatography/mass spectrometry using electron impact and chemical ionisation (positive and negative mode). The negative chemical ionisation, as most sensitive, was applied for the quantitation of both examined substances in forensic blood samples.     

Isolation of drugs from blood and tissues with XAD-2 bags

Nylon bags containing 2-g portions of Amberlite XAD-2 resin were used for systematic analysis of drugs in biosamples. The procedure requires 10 or less grams of material, two XAD-2 bags, and enables rapid and economical isolation of most common drugs. The method was demonstrated on autopsy blood spiked with 19 of the most common drugs, and was routinely used in cases of fatal and non-fatal poisoning. The eluates were clean and suitable for direct gas chromatographic and ultraviolet spectrophotometric analysis.The procedure used appeared more convenient than XAD-2 column extraction procedures. Classic solvent extraction methods were usually less efficient.