title: Simultaneous determination of nikethamide and lidocaine in human blood and cerebrospinal fluid by high performance liquid chromatography.
abstract: Nikethamide and lidocaine are often requested to be quantified simultaneously in forensic toxicological analysis. A simple reversed-phase high performance liquid chromatography (RP-HPLC) method has been developed for their simultaneous determination in human blood and cerebrospinal fluid. The method involves simple protein precipitation sample treatment followed by quantification of analytes using HPLC at 263 nm. Analytes were separated on a 5 microm Zorbax Dikema C18 column (150 mm x 4.60 mm, i.d.) with a mobile phase of 22:78 (v/v) mixture of methanol and a diethylamine-acetic acid buffer, pH 4.0. The mean recoveries were between 69.8 and 94.4% for nikethamide and between 78.9 and 97.2% for lidocaine. Limits of detection (LODs) for nikethamide and lidocaine were 0.008 and 0.16 microg/ml in plasma and 0.007 and 0.14 microg/ml in cerebrospinal fluid, respectively. The mean intra-assay and inter-assay coefficients of variation (CVs) for both analytes were less than 9.2 and 10.8%, respectively. The developed method was applied to blood sample analyses in eight forensic cases, where blood concentrations of lidocaine ranged from 0.68 to 34.4 microg/ml and nikethamide ranged from 1.25 to 106.8 microg/ml. In six cases cerebrospinal fluid analysis was requested. The values ranged from 20.3 to 185.6 microg/ml of lidocaine and 8.0 to 72.4 microg/ml of nikethamide. The method is simple and sensitive enough to be used in toxicological analysis for simultaneous determination of nikethamide and lidocaine in blood and cerebrospinal fluid.
authors.affiliation: West China School of Preclinical Medicine and Forensic Medicine, Sichuan University, No. 17, Section 3, Renmin Nan Road, Chengdu 610041, PR China.
authors.forename: Lili
authors.initials: L
authors.lastname: Chen
authors.forename: Linchuan
authors.initials: L
authors.lastname: Liao
authors.forename: Zhong
authors.initials: Z
authors.lastname: Zuo
authors.forename: Youyi
authors.initials: Y
authors.lastname: Yan
authors.forename: Lin
authors.initials: L
authors.lastname: Yang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Fu
authors.forename: Yu
authors.initials: Y
authors.lastname: Chen
authors.forename: Junhong
authors.initials: J
authors.lastname: Hou
mesh_terms: D000328:Adult; D000368:Aged; D000779:Anesthetics, Local / Q000097:blood / Q000134:cerebrospinal fluid; D000697:Central Nervous System Stimulants / Q000097:blood / Q000134:cerebrospinal fluid; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D017809:Fatal Outcome; D005554:Forensic Medicine / Q000379:methods; D006801:Humans; D008012:Lidocaine / Q000097:blood* / Q000134:cerebrospinal fluid*; D008297:Male; D008875:Middle Aged; D009552:Nikethamide / Q000097:blood* / Q000134:cerebrospinal fluid*; D012015:Reference Standards; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D000779:Anesthetics, Local; D000697:Central Nervous System Stimulants; D009552:Nikethamide; D008012:Lidocaine