Detection of drugs of abuse within electronic cigarette liquids using gas chromatography-mass spectrometry and ultra fast liquid chromatography tandem mass spectrometry
As electronic cigarettes become more prevalent in society, their use as a delivery mechanism for drugs of abuse has increased. Electronic cigarette liquids present a complex matrix due to the lack of regulation, and therefore standardization, in their manufacturing. Due to the lack of published data, development of new analytical methods to accommodate this complexity was deemed necessary. Gas chromatography-mass spectrometry (GC/MS) and liquid chromatography-tandem mass spectrometry (LC/MS/MS) methods were developed to identify the flavorants of the electronic cigarette liquids as well as identify and quantify nicotine and common drugs of abuse used with these devices. Seven drugs of abuse were investigated: methamphetamine, heroin, cocaine, fentanyl, JWH-081, JWH-018, and AM-2201. Electronic cigarette liquids from five manufacturers were sampled. From each manufacturer five "flavors" of liquids were chosen. Each liquid "flavor" was tested at the manufactures reported nicotine concentrations of 0 mg/mL, 12 mg/mL, and 24 mg/mL to give a total of 75 electronic cigarette liquid samples. Liquid-liquid extraction was performed on all samples prior to analysis by GC/MS and LC/MS/MS. Analysis was performed in replicates of five to identify the electronic cigarette liquid components as well as quantify nicotine and the four analytes of interest. For any electronic cigarette liquid labeled as containing 0 mg/mL of nicotine in which nicotine was identified, the sample was analyzed by GC/MS to quantify the nicotine level. These concentrations were compared to the naturally occurring levels of nicotine found in certain food products. Identification of the flavorants of the electronic cigarette liquids as well as the quantitation of nicotine and the four commonly abused drugs was accomplished using GC/MS and LC/MS/MS. Samples of e-liquids labeled by the manufacturer as containing 0 mg/mL of nicotine may contain detectable and quantifiable levels of nicotine. Quantitation of drugs of abuse may be affected by matrix components and was found to be dependent on both the specific e-liquid being used with the electronic cigarette as well as the analyte being investigated.