Recent advances in MS methods for nicotine and metabolite analysis in human matrices: clinical perspectives

Simultaneous quantification of urinary tobacco and marijuana metabolites using solid-supported liquid-liquid extraction coupled with liquid chromatography tandem mass spectrometry

Co-exposure to tobacco and marijuana has become common in areas where recreational marijuana use is legal. To assist in the determination of the combined health risks of this co-exposure, an analytical method capable of simultaneously measuring tobacco and marijuana metabolites is needed to reduce laboratory costs and the required sample volume. So far, no such analytical method exists. Thus, we developed and validated a method to simultaneously quantify urinary levels of trans-3'-hydroxycotinine (3OH-COT), cotinine (COT), and 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (COOH-THC) to assess co-exposure to tobacco and marijuana. Urine (200 µL) was spiked with labelled internal standards and enzymatically hydrolyzed to liberate the conjugated analytes before extraction using solid-supported liquid-liquid extraction (SLE) with ethyl acetate serving as an eluent. The target analytes were separated on a C18 (4.6 × 100 mm, 5 μm) analytical column with a gradient mobile phase elution and analyzed using tandem mass spectrometry with multiple reaction monitoring of target ion transitions. Positive electrospray ionization (ESI) was used for 3OH-COT and COT, while negative ESI was used for COOH-THC. The total run time was 13 min. The extraction recoveries were 18.4-23.9 % (3OH-COT), 65.1-96.8 % (COT), and 80.6-95.4 % (COOH-THC). The method limits of quantification were 5.0 ng/mL (3OH-COT) and 2.5 ng/mL (COT and COOH-THC). The method showed good accuracy (82.5-98.5 %) and precision (1.22-6.21 % within-day precision and 1.42-6.26 % between-day precision). The target analytes were stable for at least 144 h inside the autosampler (10 °C). The analyses of reference materials and 146 urine samples demonstrated good method performance. The use of a 96-well plate for preparation makes the method useful for the analysis of large numbers of samples.

Nicotine in Complex Samples: Recent Updates on the Pretreatment and Analysis Method

Nicotine is a significant evaluation index of tobacco and its related products' quality, but nicotine overdose can pose serious health hazards and cause addiction and dependence, thus it can be seen that it is necessary to find suitable and efficient detection methods to precisely detect nicotine in diverse samples and complex matrices. In this review, an updated summary of the latest trends in pretreatment and analytical techniques for nicotine is provided. We reviewed various sample pretreatment methods, such as solid phase extraction, solid phase microextraction, liquid phase microextraction, QuEChERS, etc., and diverse nicotine assay methods including liquid chromatography, gas chromatography, electrochemical sensors, etc., focusing on the developments since 2015. Furthermore, the recent progress in the applications and applicability of these techniques as well as our prospects for future developments are discussed.HighlightsUpdated pretreatment and analysis methods of nicotine were systematically summarized.Microextraction and automation were main development trends of nicotine pretreatment.The introduction of novel materials added luster to nicotine pretreatment.The evolutions of ion source and mass analyzer were emphasized.

Nicotine metabolism and its association with CYP2A6 genotype among Indigenous people in Alaska who smoke

Prevalence of smoking is higher in Alaska Native and American Indian (ANAI) populations living in Alaska than the general US population. Genetic factors contribute to smoking and cessation rates. The objective of this study was to compare CYP2A6 genetic variation and CYP2A6 enzyme activity toward nicotine in an ANAI population. ANAI (N = 151) people trying to quit smoking were recruited. DNA samples were genotyped for CYP2A6 variants *1X2A, *1B, *2, *4, *9, *10, *12, and *35. Multiple nicotine metabolites were measured in plasma and urine samples, including cotinine and 3′‐hydroxycotinine used to determine CYP2A6 activity (e.g., nicotine metabolite ratio [NMR]). We calculated summary statistics for all of the genotypes and metabolites and assigned CYP2A6 activity scores based on known information. We studied the association of CYP2A6 variants with the NMR and smoking histories. The overall frequency of the CYP2A6*1B gain of function allele was high in the ANAI versus non‐ANAI populations in other studies. Both *4 null and *9 decrease of function alleles had frequencies similar to previous studies of ANAI populations. In a multivariate analysis, the genotype‐inferred CYP2A6 activity score was associated with both plasma and urine NMR (p value = 8.56E‐08 and 4.08E‐13, respectively). Plasma NMR was also associated with duration of smoking (p value < 0.01) but not urinary total nicotine equivalents uncorrected for creatinine (TNE9_uc) or biological sex. Urine NMR was significantly associated (p value < 0.01) with TNE9_uc. Variation in NMR in this ANAI population is explained in part by CYP2A6 genetic variation.