tailieunhanh - Drugs and Poisons in Humans - A Handbook of Practical Analysis (Part 15)

Introduction: Chloroform exerts a suppressing effect on the central nervous system. It had been used as a general anaesthetic since the 19th century, but it disappeared, because of its hepatotoxicity and arrhythmia-inducing effects. It is now being used for industrial purposes, such as a solvent, extracting reagent, refrigerant and chemical material. Chloroform poisoning can be seen in accidental, suicidal [1] and homicidal cases. Dichloromethane (methylene dichloride, methylene chloride) is also being widely used in industries as a solvent and refrigerant like chloroform, and causing many poisoning cases due to accidents and suicides [2]. Recently, dichloromethane has become of interest as. | Chloroform and dichloromethane by Kanako Watanabe Introduction Chloroform exerts a suppressing effect on the central nervous system. It had been used as a general anaesthetic since the 19th century but it disappeared because of its hepatotoxicity and arrhythmia-inducing effects. It is now being used for industrial purposes such as a solvent extracting reagent refrigerant and chemical material. Chloroform poisoning can be seen in accidental suicidal 1 and homicidal cases. Dichloromethane methylene dichloride methylene chloride is also being widely used in industries as a solvent and refrigerant like chloroform and causing many poisoning cases due to accidents and suicides 2 . Recently dichloromethane has become of interest as a substitute of chlorofluorocarbon because the latter was found to accelerate the depletion of the ozone layer and is in the line of being abolished completely. Since both chloroform and dichloromethane are volatile compounds their analysis is usually made by the headspace extraction and GC detection. In this chapter a simple headspace GC method using dichloromethane as internal standard IS for assays of chloroform and vice versa is presented 3 . Reagent and their preparation i. Reagents Chloroform dichloromethane and methanol of special grade can be purchased from Wako Pure Chemical Industries Ltd. Osaka Japan and many other manufacturers. ii. Preparation A 337-pL volume of chloroform and a 377-pL volume of dichloromethane are separately dissolved in methanol to prepare each 100 mL solution as stock solutions. Each solution is diluted 5-fold with methanol a 10-pL volume containing 10 pg of each compound is added to mL whole blood as IS and mixed well. Springer-Verlag Berlin Heidelberg 2005 144 Chloroform and dichloromethane GC Conditions3 GC column b a DB-1 fused silica wide-bore capillary column 30 m x mm i. d. film thickness 5 pm J W Scientific Folsom CA USA . GC conditions an HP 5890 Series gas chromatograph Agilent .