Advancing the use of molecularly imprinted polymers in bioanalysis: the selective extraction of cotinine in human urine.

Aim: To characterize a molecularly imprinted polymer via precipitation polymerization for the extraction of cotinine in urine. Methods: The polymer was created via precipitation polymerization. Physical characteristics of the polymer were assessed via scanning electron microscopy, Fourier transform infrared spectroscopy and thermogravimetric analysis. The polymer adsorption capacity was assessed and an solid-phase extraction method from urine by LC-MS/MS was developed. Results: The polymer had small, spherical morphology and little thermal decomposition. The extraction method yielded cotinine recoveries of 77-103% in urine. The molecularly imprinted polymer adsorption capacity for cotinine was 448.2 ± 2.1 µg/mg. Common interferants did not affect cotinine's extraction. Conclusion: The resulting polymer was determined to be specific for cotinine and can be used for the detection of cotinine in urine for clinical samples.

Determination of Patient Adherence for Duloxetine in Urine.

Duloxetine, known by its brand name, CymbaltaTM, is a selective serotonin and norepinephrine reuptake inhibitor used to treat major depressive disorders. Determination of patient compliance for duloxetine is typically determined through medication possession ratio (MPR) or plasma concentrations. The purpose of this paper was to characterize normal urinary duloxetine concentrations in patients prescribed duloxetine to monitor patient adherence. Patient data collected from routine screens for duloxetine concentrations in urine were included in this study. Inclusion criteria consisted of patients who were prescribed duloxetine and (i) tested positive for duloxetine, (ii) tested negative for illicit substances and (iii) included creatinine, age and duloxetine dose administered. Of the 5,592 patient urines screened, 2,004 of the results fit into the inclusion criteria. Positive urine concentrations of duloxetine ranged from 50 to 2,722 ng/mL. Duloxetine urine concentrations were normalized to creatinine and dose further characterized by sex, age, body mass index (BMI) and dose in milligrams. Sample distribution included urines collected from 1,487 females and 517 males. The age range of the specimen donors was between 15 and 90 years old with an average age of 52. BMI levels ranged from 13.9 (underweight) to 88.1 (obese), with the average BMI being 33.5. The most common dose of duloxetine prescribed was a daily, oral dose of 60 mg. Analysis of the normalized, transformed creatinine concentrations showed that there was a significant statistical difference (P < 0.05) in the urinary duloxetine concentrations by sex and by dose (mg). Female patients further showed a statistical difference in urinary duloxetine concentration in age groups 18-64 and 64 and older. By characterizing urinary duloxetine concentrations in patients prescribed the medication, normalized distributions of data ranges have been established. These data ranges for urinary duloxetine concentrations can be used to determine patient compliance with duloxetine in routine, clinical samples.

Characterization of molecularly imprinted polymers for the extraction of tobacco alkaloids and their metabolites in human urine.

Molecularly imprinted polymers (MIPs) are synthetic polymers designed to selectively extract target analytes from complex matrices (including biological matrices). The literature shows that MIPs have a degree of cross-selectivity from analytes within the same class of compounds. A commercially available MIP for tobacco-specific nitrosamines (TSNAs) is designed to be class selective for four TSNA compounds. This study sought to characterize the extent of cross-selectivity of the TSNA MIPs with other tobacco alkaloids. Cross-selectivity and recovery of the SupelMIP™ TSNA SPE cartridges was assessed with N-nitrosonornicotine (NNN), nicotine, cotinine and morphine. Their recoveries were compared with the recoveries of a nonimprinted polymer SPE cartridge, and two traditional SPE cartridges: a Waters mixed-mode cation exchange cartridge and a Waters hydrophilic-lipophilic balance cartridge. NNN and cotinine had the highest recoveries with the MIP cartridge, over 80%, and cotinine samples in urine had >80% recoveries. Nicotine had highly variable recoveries, possibly owing to differing chemical properties from the TSNAs. All three analytes had significantly different recoveries with the MIP cartridges compared with the traditional SPE cartridges. Morphine displayed nonspecific interactions with the MIP cartridges. Utilization of the TSNAs' cross-selectivity allows for simultaneous extraction and identification of multiple tobacco biomarkers using one extraction technique.

Direct analysis of tobacco specific nitrosamines in tobacco products using a molecularly imprinted polymer-packed column.

Tobacco specific nitrosamines (TSNAs) are highly carcinogenic by-products in tobacco samples, and their presence is regulated by the Food and Drug Administration. Molecularly imprinted polymers (MIPs) are synthetic polymers that have been "imprinted" with a template analyte in a co-polymer system, and can selectively extract analytes from complex matrices. MIPs can be incorporated into online systems, replacing traditional high performance liquid chromatography (HPLC) columns. MIP material specific for TSNAs was packed into an empty HPLC column using a slurry packing technique. The developed method with the MIP-packed HPLC column was validated on a LC-MS/MS system for the quantitation of N-nitrosonornicotine (NNN) and 4- (methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in commercial tobacco products. The method was linear over .1-10 ng/ml (.4-10 µg/g) for NNN and NNK. The limit of detection (LOD) was .03 ng/ml (12 µg/g) and the limit of quantitation (LOQ), .1 ng/ml (.4 µg/g). All column uniformity parameters with the exception of theoretical plate number were within the accepted criteria (% RSD values <15%). Theoretical plate number was <250, owing to the large (50 µm) sized MIP particles. Twenty-six tobacco products contained TSNA concentrations that were consistent with reported literature values. The TSNA-MIP based HPLC column effectively replaced a traditional reverse phase HPLC column, and was used for the direct analysis of nicotine and tobacco products without extensive sample preparation prior to instrumental analysis.

Growing Trends in the Efficient and Selective Extraction of Compounds in Complex Matrices Using Molecularly Imprinted Polymers and Their Relevance to Toxicological Analysis.

In the world of forensic and clinical toxicology, proper sample preparation is one of the key steps in identification and quantification of drugs of abuse. Traditional extraction methods such as solid-phase extraction and liquid-liquid extraction are often laborious and nonselective for the target analytes being measured. Molecularly imprinted polymers (MIPs) can be synthesized for sample extraction and their versatility allows the polymer to be employed in off-line, benchtop extractions or on/in-line instrument extractions, offering a faster and more selective sample preparation without the risk of interfering matrix effects. This review details the synthesis and applications of MIP materials for the extraction of drug compounds from biological matrices in publications from 1994 to today.

Characterization of E-cigarette coil temperature and toxic metal analysis by infrared temperature sensing and scanning electron microscopy - energy-dispersive X-ray.

INTRODUCTION: Electronic cigarettes (e-cigarettes) have rapidly evolved since their introduction to the U.S. market. The rebuildable atomizer (RBA) offers user-driven modification to the heating element (coil) and wicking systems. Different coil materials can be chosen based on user needs and preferences. However, the heating element of an e-cigarette is believed to be one-source for toxic metal exposure. METHODS: E-cigarette coils from Kanthal and nichrome wires were constructed in a contact and non-contact configuration and heated at four voltages. The maximum temperatures of the coils were measured by infrared temperature sensing when dry and when saturated with 100% vegetable glycerin or 100% propylene glycol. The metal composition of each coil was analyzed with Scanning Electron Microscopy-Energy-Dispersive X-Ray (SEM-EDX) when new, and subsequently after 1, 50, and 150 heat cycles when dry. RESULTS: The coils reached temperatures above 1000 °C when dry, but were below 300 °C in both liquid-saturated mediums. Metal analysis showed a decrease of 9-19% chromium and 39-58% iron in Kanthal wire and a decrease of 12-14% iron and 39-43% nickel in nichrome wire after 150 heat cycles. Significant metal loss was observed after one heat cycle for both coil alloys and configurations. CONCLUSIONS: The loss of metals from these heat cycles further suggests that the metals from the coils are potentially entering the aerosol of the e-cigarette, which can be inhaled by the user.

Author Correction: The Effect of Electronic Cigarette User Modifications and E-liquid Adulteration on the Particle Size Profile of an Aerosolized Product.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

The Effect of Electronic Cigarette User Modifications and E-liquid Adulteration on the Particle Size Profile of an Aerosolized Product.

Electronic cigarettes (e-cigarettes) are an alternate nicotine delivery system that generate a condensation aerosol to be inhaled by the user. The size of the droplets formed in the aerosol can vary and contributes to drug deposition and ultimate bioavailability in the lung. The growing popularity of e-cigarette products has caused an increase in internet sources promoting the use of drugs other than nicotine (DOTNs) in e-cigarettes. The purpose of this study was to determine the effect of various e-cigarette and e-liquid modifications, such as coil resistance, battery voltage, and glycol and drug formulation, on the aerosol particle size. E-liquids containing 12 mg/mL nicotine prepared in glycol compositions of 100% propylene glycol (PG), 100% vegetable glycerin (VG), or 50:50 PG:VG were aerosolized at three voltages and three coil resistances. Methamphetamine and methadone e-liquids were prepared at 60 mg/mL in 50:50 PG:VG and all e-liquids were aerosolized onto a 10 stage Micro-Orifice Uniform Deposit Impactor. Glycol deposition correlated with drug deposition, and the majority of particles centered between 0.172-0.5 µm in diameter, representing pulmonary deposition. The 100% PG e-liquid produced the largest aerosol particles and the 100% VG and 50:50 PG:VG e-liquids produced ultra-fine particles <0.3 µm. The presence of ultrafine particles indicates that drugs can be aerosolized and reach the pulmonary alveolar regions, highlighting a potential for abuse and risk of overdose with DOTNs aerosolized in an e-cigarette system.

The unexpected identification of the cannabimimetic, 5F-ADB, and dextromethorphan in commercially available cannabidiol e-liquids.

Electronic cigarettes (e-cigarettes) were developed as an alternative method for nicotine delivery and had a significant surge in popularity. E-liquids are formulations used in e-cigarettes, and consist of a ratio of propylene glycol (PG) and vegetable glycerin (VG), a pharmaceutical and/or herbal remedy and, usually, a flavoring agent. Presented is the evaluation of nine cannabidiol (CBD) e-liquids from a single manufacturer for cannabinoids and other psychoactive compounds by Direct Analysis in Real Time Mass Spectrometry (DART-MS) and Gas Chromatography Mass Spectrometry (GC/MS). The analysis of these products resulted in the detection of CBD in all nine produces and the unexpected detections of 5-fluoro MDMB-PINACA (5F-ADB) in four of the products and dextromethorphan (DXM) in one of the products. The analysis of these products illustrates the potential quality control issues that can occur in an unregulated industry. CBD products are believed by many users to offer heath benefits, but the detection of a dangerous cannabimimetic, 5F-ADB, and DXM in these products illustrates the need for oversight.

Evaluation of Nicotine and the Components of e-Liquids Generated from e-Cigarette Aerosols.

Electronic cigarettes (e-cigs) deliver nicotine in an aerosol to the user that simulates the smoke of traditional cigarettes purportedly without the pathology of inhaling tobacco smoke due to the absence of combustion. Advanced versions of e-cigs enable the user to potentially moderate the concentration of drug in the aerosol by selecting from a range of voltages on the power supply. A method was developed to trap the aerosol produced by a KangerTech AeroTank, 1.8 Ω preassembled atomizer in order to analyze the concentration of nicotine and to evaluate the constituents of the aerosol at various voltages on the power supply. A 12-mg/mL formulation of nicotine in 50:50 propylene glycol (PG):vegetable glycerin (VG) was used to produce aerosol at 3.9, 4.3 and 4.7 V. The aerosol was trapped in a simple glass assemblage and analyzed by a 3200 Q Trap HPLC-MS-MS. The dose of nicotine delivered in the aerosol at 3.9, 4.3 and 4.7 V was determined to be 88 ± 12 µg, 91 ± 15 µg and 125 ± 22 µg. The average recovery of nicotine in the trap across the voltages was 99.8%. The glass trap system was an effective device for collecting the aerosol for analysis and an increase in drug yield was observed with increasing voltage from the power supply on the e-cig. The glass trap system was also used in combination with a 100-µm solid-phase microextraction fiber to capture the aerosol and analyze it via DART-MS and GC-MS. Four commercial e-liquids labeled to contain nicotine were aerosolized at 4.3 V. The pharmacologically active ingredient, nicotine, as well as PG, VG and a number of flavoring agents found in these formulations were identified.

The Blue Lotus Flower (Nymphea caerulea) Resin Used in a New Type of Electronic Cigarette, the Re-Buildable Dripping Atomizer.

The blue lotus flower (Nymphea caerulea) is an Egyptian water lily containing apomorphine and nuciferine. Apomorphine has been described as a psychoactive alkaloid and is a non-selective dopamine agonist primarily used to treat Parkinson's disease as it stimulates dopamine receptors and improves motor function. Nuciferine is an alkaloid associated with dopamine receptor blockade. Today, blue lotus flower is used as a sleep aid and anxiety reliever. The rebuildable dripping atomizer (RDA) is an electronic cigarette that allows direct application of an e-liquid onto the coil in the atomizer for aerosolization, compared to a typical electronic cigarette where the e-liquid is wicked from a storage vessel to the coil. Our laboratory received a dark-brown resin material from a concerned parent. The resin had been confiscated from an adolescent who had a reported history of marijuana use. The resin was later identified as blue lotus flower (N. caerulea). This resin, together with four commercially available blue lotus products, was analyzed for content. Apomorphine was detected in two samples, and nuciferine was detected in all five samples. The confiscated resin was determined to contain no apomorphine and 4300 ng/g of nuciferine. The nuciferine resin was shown to aerosolize using aRDA electric cigarette.