tailieunhanh - Drugs and Poisons in Humans - A Handbook of Practical Analysis (Part 17)

Introduction: Alkyl nitrites are highly volatile organic solvents of aliphatic alcohol esters of nitrites [1]. Amyl nitritea, butyl nitrite and isobutyl nitrite are the representative alkyl nitrites; their boiling points are 98, 78 and 67 °C, respectively. Amyl nitrite is being widely used as a detoxicant for cyanide poisoning, because alkyl nitrites oxidize hemoglobin in erythrocytes to yield methemogloblin, which is bound with cyanide to inactivate it [1]. Alkyl nitrites also show a coronary artery-dilating effect, and had been, therefore, used for the treatment of angina pectoris many years ago [2]; the pharmacological effect of the dilation of the coronary. | Alkyl n itrites by Yasuo Seto Introduction Alkyl nitrites are highly volatile organic solvents of aliphatic alcohol esters of nitrites 1 . Amyl nitrite butyl nitrite and isobutyl nitrite are the representative alkyl nitrites their boiling points are 98 78 and 67 C respectively. Amyl nitrite is being widely used as a detoxicant for cyanide poisoning because alkyl nitrites oxidize hemoglobin in erythrocytes to yield methemogloblin which is bound with cyanide to inactivate it 1 . Alkyl nitrites also show a coronary artery-dilating effect and had been therefore used for the treatment of angina pectoris many years ago 2 the pharmacological effect of the dilation of the coronary arteries was found due to the action of nitrogen monoxide produced by decomposition of alkyl nitrites 3 . They are being mainly used as materials for manufacturing drugs or as reagents for synthesis in industries they are also used as aromatics. Because of their pharmacological effect alkyl nitrites are being abused as uncontrolled inhalant drugs and causing a social problem 4 . Although there are many reports on toxic and fatal cases due to alkyl nitrites 5 reports on their fatal doses are few it is estimated that oral ingestion of 10-15 mL of each alkyl nitrite causes serious methemoglobinemia 6 . The LD50 value for an alkyl nitrite is reported to be 205 mg kg. There are not many cases of analysis of alkyl nitrites in the field of forensic toxicology. In this chapter the methods for analysis of the compounds by headspace HS -gas chromatography GC and liquid-liquid extraction-GC are presented. Determination of isobutyl nitrite in aqueous solution by headspace-GC Reagents and their preparation A 115-pL volume 100 mg of isobutyl nitrite Tokyo Kasei Kogyo Co. Ltd. Tokyo Japan and other manufacturers is dissolved in acetone to prepare 10 mL stock solution 10 mg mL preservable for a week in a refrigerator b. The stock solution is diluted 2 000-fold with acetone to prepare standard solution