Using Liquid Chromatography-Isotope Ratio Mass Spectrometry for Detection of Economically Motivated Adulteration of Maple Syrup.

BACKGROUND: Maple syrup is a sought-after commodity, and used as a condiment and a sweetener. Also, it is an active target of economically motivated adulteration (EMA), similar to other foods such as lemon juice and honey. OBJECTIVE: This study is aimed to detect low cost sugar adulteration in maple syrup via an internal standard method using malic acid through solid-phase extraction (SPE) and LC with isotope ratio mass spectrometric detection (LC-IRMS). METHODS: In this work, an optimized SPE sample preparation procedure was used for the isolation of organic acids from maple syrup. Using LC-IRMS, malic acid was separated from other organic acids and the δ13C value of malic acid was determined. Eleven maple syrup samples, domestic or imported from Canada, were evaluated for 13C/12C ratios (δ13C values) using combustion module-cavity ring down spectrometry (CM-CRDS) and compared to the δ13C values obtained from well-established elemental analyzer-isotope ratio mass spectrometry (EA-IRMS) methods. The δ13C values of isolated malic acid analyzed by SPE-LC-IRMS were used as internal standards and compared to the δ13C values of bulk maple syrup; difference (δ13Csugars - δ13Cmalic acid) values greater than 3.6‰ are indicative of low-cost sugar adulteration. RESULTS: Overall, the results obtained from SPE-LC-IRMS provided a faster, novel analysis approach for determining low-cost sugar adulteration in maple syrup for regulatory purposes. This method also provided lower detectable limits of adulteration versus current literature reports using bulk analysis and comparable detection limits to Tremblay and co-workers who utilized an internal standard method. CONCLUSION: SPE-LC-IRMS is a robust method that can be used for detecting adulteration in maple syrup samples for regulatory purposes. HIGHLIGHTS: SPE-LC-IRMS is a faster, novel analysis approach for determining C4 adulteration in maple syrup with lower detection limits.

Screening suspect pharmaceuticals for illicit designer benzodiazepines using raman, SERS, and FT-IR prior to comprehensive analysis using LC-MS.

The emergence of illicit designer benzodiazepines with high dependency and no approved clinical use are of great US public health concern. Due to the increasing numbers of illicit designer benzodiazepines encountered in the US supply chain, there is a need to develop robust analytical methods that can rapidly detect these chemicals. Suspect counterfeit tablets, powders, or liquid formulations were first screened using Raman spectroscopy and surface-enhanced Raman scattering spectroscopy (SERS) for the presence of legal or illicit benzodiazepines, and then further analyzed using Fourier-transform infrared (FT-IR) spectroscopy and liquid chromatography with tandem mass spectrometric detection (LC-MS). Several microextraction procedures were developed and used to extract benzodiazepines from samples prior to SERS, FT-IR, and LC-MS analysis. Conventional Raman analyses using handheld Raman spectrometers afforded the ability to examine samples through enclosed plastic bags but were only able to detect high concentrations of various benzodiazepines in the suspect samples. The developed SERS methods were sufficient for detecting at least one benzodiazepine in the low-dose suspect samples, thereby allowing prioritization using other analytical tools that require more sample preparation and time-consuming analyses. The use of FT-IR spectroscopy coupled with extraction and spectral subtraction was found to be selective to multiple benzodiazepines and various excipients in the analyzed samples. This study demonstrated that the developed SERS and FT-IR procedures could be used in satellite laboratories to screen suspect packages at ports of entry and prioritize samples for additional laboratory-based analyses in an effort to prevent dangerous and illicit pharmaceutical products from reaching the US supply chain.

EVALI Vaping Liquids Part 2: Mass Spectrometric Identification of Diluents and Additives.

The vaping liquid additive vitamin E acetate (VEA) was strongly linked to the 2019 United States nationwide outbreak of pulmonary lung illness (EVALI) associated with e-cigarettes or vaping liquids. Our laboratory received over 1,000 vaping liquid products for identification of the vaping liquid additives, including hundreds of vaping products from EVALI patients. In this work, we present results obtained for the GC-MS identification of numerous vaping liquid additives in a large subset of ca. 300 Cannabis vaping liquids, including vitamin E acetate, medium chain triglycerides oil (MCT oil), polyethylene glycols, squalane, triethyl citrate, dipropylene glycol dibenzoate (DPG dibenzoate), pine rosin acids, pine rosin methyl esters, and sucrose acetate isobutyrate (SAIB). Confirmation of DPG dibenzoate and SAIB using LC-HRMS is also presented. GC-MS analysis for additives identified as the parent compounds was conducted after separation on a commercial 5% phenyl phase. GC-MS analysis for additives identified as the trimethylsilyl derivatives was conducted after separation on a commercial 35% silphenylene phase. LC-HRMS analysis was conducted using gradient elution with either C18 or phenyl-hexyl phases and determination of exact masses for the target compounds. In addition to providing rapid methods for the identification of vaping liquid additives, this work highlights the variety of Cannabis vaping liquid additives in current use.

EVALI Vaping Liquids Part 1: GC-MS Cannabinoids Profiles and Identification of Unnatural THC Isomers.

Tetrahydrocannabinol (THC)-containing products played a major role in the 2019 US nationwide outbreak of pulmonary lung illness associated with e-cigarettes or vaping liquids (EVALI). Due to the severity of the illness which resulted in 68 deaths, a comprehensive identification of the components in the vaping liquids was required. Our laboratory received over 1000 vaping liquid products for analysis including hundreds of vaping products from EVALI patients. In this work, we present the results for the GC-MS identification of the cannabinoids from a large subset of ca. 300 Cannabis-based vaping liquids, with emphasis on the identification of a series of unnatural THC isomers. GC-MS analysis was conducted using a validated, published method in which the cannabinoids were identified as the trimethylsilyl derivatives after separation on a commercial 35% silphenylene phase. Δ9- Tetrahydrocannabinol is the naturally occurring THC isomer found in the Cannabis plant, and was found in the majority of the vaping liquids. However, we also identified the presence of one or more additional THC isomers in many of the vaping liquids including Δ8-tetrahydrocannabinol, Δ6a,10a-tetrahydrocannabinol, Δ10-tetrahydrocannabinol, and exo-tetrahydrocannabinol. Significant or major amounts of unnatural THC isomers were found in over 10% of the THC vaping liquids, with lesser amounts found in another 60% of the vaping liquids. Exposure of the Cannabis source materials (such as marijuana concentrates or converted hemp materials) to chemical and thermal treatments during manufacturing, is proposed as the primary cause for the THC isomerizations.

Simultaneous Temperature Measurements and Aerosol Collection During Vaping for the Analysis of Δ9-Tetrahydrocannabinol and Vitamin E Acetate Mixtures in Ceramic Coil Style Cartridges.

Incidence of e-cigarette, or vaping, product use-associated lung injury (EVALI) has been linked to the vaping of tetrahydrocannabinol (THC) products to which vitamin E acetate (VEA) has been added. In this work we vaped THC/VEA mixtures at elevated power levels using a variety of ceramic coil vaping cartridges and a commercially available vaping device, while simultaneously measuring temperature and collecting the vaporized condensate. The collected vapor condensate was analyzed for evidence of VEA decomposition by GC/MS, GC/FT-IR/MS, and LC-APCI-HRMS/MS. Mean temperature maxima for all examined cartridges at the selected power exceeded 430°C, with a range of 375-569°C, well beyond that required for thermal decomposition of VEA. The percent recovery of VEA and Δ9-THC from the vaporized mixture in six cartridges ranged from 71.5 to 101% and from 56.4 to 88.0%, respectively. Analysis of the condensed vaporized material identified VEA decomposition products duroquinone (DQ), 1-pristene, and durohydroquinone monoacetate (DHQMA); a compound consistent with 4-acetoxy-2,3,5-trimethyl-6-methylene-2,4-cyclohexadienone (ATMMC) was also detected. The concentration of DQ produced from vaporization of the THC/VEA mixture in one cartridge was found to be 4.16 ± 0.07 µg per mg of vapor condensate.