Trace Detection of Adulterants in Illicit Opioid Samples Using Surface-Enhanced Raman Scattering and Random Forest Classification.

The detection of trace adulterants in opioid samples is an important aspect of drug checking, a harm reduction measure that is required as a result of the variability and unpredictability of the illicit drug supply. While many analytical methods are suitable for such analysis, community-based approaches require techniques that are amenable to point-of-care applications with minimal sample preparation and automated analysis. We demonstrate that surface-enhanced Raman spectroscopy (SERS), combined with a random forest classifier, is able to detect the presence of two common sedatives, bromazolam (0.32-36% w/w) and xylazine (0.15-15% w/w), found in street opioid samples collected as a part of a community drug checking service. The Raman predictions, benchmarked against mass spectrometry results, exhibited high specificity (88% for bromazolam, 96% for xylazine) and sensitivity (88% for bromazolam, 92% for xylazine) for the compounds of interest. We additionally provide evidence that this exceeds the performance of a more conventional approach using infrared spectral data acquired on the same samples. This demonstrates the feasibility of SERS for point-of-care analysis of challenging multicomponent samples containing trace adulterants.

Simultaneous quantitation of urinary albumin and creatinine for rapid clinical albuminuria diagnostics using high-throughput paper spray mass spectrometry.

Albuminuria is a clinical condition associated with poor kidney function, diagnosed by determining the ratio of albumin to creatinine concentrations in patient urine samples. We present a high-throughput paper spray mass spectrometry (PS-MS) method for simultaneous quantitation of urinary albumin and creatinine for potential diagnosis of albuminuria. Minimal (urine dilution) or no sample preparation is required. The analytical performance of the method was evaluated, achieving linear calibration curves (R2 > 0.99) with little inter-day variability in the slope (N = 5 days), exhibiting coefficient of variation (CV) of 8% and 3% for albumin and creatinine, respectively. LOD and LOQ for albumin were 2.1 and 7.0 mg L-1, and for creatinine were 0.01 and 0.03 mmol L-1, respectively. Intra- and inter-day (N = 5) precisions (%CV) and accuracies (%bias) were <10% and ±11%, respectively, for both analytes. The method was applied to determine albumin-to-creatinine ratios in anonymous human patient urine samples (N = 56), and a correlation of R2 = 0.9744 was achieved between the PS-MS results and validated clinical method results. This work demonstrates the utility of PS-MS to simultaneously quantify a large (albumin) and a small (creatinine) molecule directly in patient urine samples, and its potential as a tool for clinical albuminuria diagnostics.

Paper spray mass spectrometry combined with machine learning as a rapid diagnostic for chronic kidney disease.

A new analytical method for chronic kidney disease (CKD) detection utilizing paper spray mass spectrometry (PS-MS) combined with machine learning is presented. The analytical protocol is rapid and simple, based on metabolic profile alterations in urine. Anonymized raw urine samples were deposited (10 µL each) onto pointed PS-MS sample strips. Without waiting for the sample to dry, 75 µL of acetonitrile and high voltage were applied to the strips, using high resolution mass spectrometry measurement (15 s per sample) with polarity switching to detect a wide range of metabolites. Random forest machine learning was used to classify the resulting data. The diagnostic performance for the potential diagnosis of CKD was evaluated for accuracy, sensitivity, and specificity, achieving results >96% for the training data and >91% for validation and test data sets. Metabolites selected by the classification model as up- or down-regulated in healthy or CKD samples were tentatively identified and in agreement with previously reported literature. The potential utilization of this approach to discriminate albuminuria categories (normo, micro, and macroalbuminuria) was also demonstrated. This study indicates that PS-MS combined with machine learning has the potential to be used as a rapid and simple diagnostic tool for CKD.

Beyond a spec: assessing heterogeneity in the unregulated opioid supply.

BACKGROUND: Drug checking services aim to provide compositional information for the illicit drug supply and are being employed in public health responses to extreme rates of overdose associated with fentanyl within street opioids. The technologies used within these services range from basic qualitative tests, such as immunoassay test strips, to comprehensive quantitative analyses, such as mass spectrometry. In general, there is concern that heterogeneity of a drug mixture adds significant uncertainty when using drug checking results based on a small subsamples. The presence of hot spots of active drug components in this context is often termed the 'chocolate chip cookie effect'. Establishing the limitations of the service are essential for interpretation of the results. METHODS: This study assesses the consequence of drug heterogeneity and sampling of consumer level opioid purchased in Victoria, British Columbia ( n = 21 , 50-100 mg each) on quantitative fentanyl results determined from testing with paper spray mass spectrometry. RESULTS: Using descriptive statistics, such as relative standard deviation and interquartile range, the results demonstrate varied distributions of fentanyl concentrations within a single drug batch. However, the presence of hot spots, defined as outliers, were relatively rare. CONCLUSIONS: This study found that the variability in fentanyl concentration from drug heterogeneity and sampling is greater than that attributed to the analytical technique. On a practical level, this provides data to help guide communication of limitations of drug checking services, supporting the aim of trust and transparency between services and people who use drugs. However, if drug checking services continue to be restricted from fully engaging with the reality of manufacturing, buying, selling, mixing and dosing practices, the accuracy, usefulness, and impact will always be limited.

PAMAM-Functionalized Paper as a New Substrate for the Paper Spray Mass Spectrometry Measurement of Proteins.

Paper surface functionalization with polyamidoamine (PAMAM) dendrimers has been developed for increased sensitivity analysis of proteins by paper spray mass spectrometry (PS-MS). PAMAM is a branched polymeric compound with an ethylenediamine core linked to repeating PAMAM units that generates an outer surface rich in primary amines. These positively charged amine groups can interact electrostatically with negatively charged residues (e.g., aspartate, glutamate) on the protein surface. PAMAM inner amide moieties can also promote hydrogen bonding with protein surface oxygens, making PAMAM a useful material for protein extraction. PAMAM-functionalized PS-MS paper strips were used to extract proteins from biofluids, dipped in acetonitrile to remove unbound constituents, dried, and then measured with PS-MS. The use of this strategy was optimized and compared with unmodified paper strips. PAMAM-functionalized paper substrates provided sixfold greater sensitivity for albumin, 11-fold for hemoglobin, sevenfold for insulin, and twofold for lysozyme. The analytical performance of the functionalized paper substrate was evaluated through the analysis of albumin in urine, achieving linearity with R2 > 0.99, LOD of 1.1 µg mL-1, LOQ of 3.8 µg mL-1, precision better than 10%, and relative recovery 70-83%. The method was applied to quantify urinary albumin from nine anonymous patient samples (concentrations ranged from 6.5 to 77.4 µg mL-1), illustrating its potential for the diagnosis of microalbuminuria. These data demonstrate the utility of paper modification with the PAMAM dendrimer for sensitive PS-MS analysis of proteins, opening a path for further applications in clinical diagnosis through the analysis of disease-related proteins.

The future is bright: Biofortification of common foods can improve vitamin D status.

Vitamin D deficiency is a global concern, linked to suboptimal musculoskeletal health and immune function, with status inadequacies owing to variations in UV dependent cutaneous synthesis and limited natural dietary sources. Endogenous biofortification, alongside traditional fortification and supplement usage is urgently needed to address this deficit. Evidence reviewed in the current article clearly demonstrates that feed modification and UV radiation, either independently or used in combination, effectively increases vitamin D content of primary produce or ingredients, albeit in the limited range of food vehicles tested to date (beef/pork/chicken/eggs/fish/bread/mushrooms). Fewer human trials have confirmed that consumption of these biofortified foods can increase circulating 25-hydroxyvitamin D [25(OH)D] concentrations (n = 10), which is of particular importance to avoid vitamin D status declining to nadir during wintertime. Meat is an unexplored yet plausible food vehicle for vitamin D biofortification, owing, at least in part, to its ubiquitous consumption pattern. Consumption of PUFA-enriched meat in human trials demonstrates efficacy (n = 4), lighting the way for exploration of vitamin D-biofortified meats to enhance consumer vitamin D status. Response to vitamin D-biofortified foods varies by food matrix, with vitamin D3-enriched animal-based foods observing the greatest effect in maintaining or elevating 25(OH)D concentrations. Generally, the efficacy of biofortification appears to vary dependent upon vitamer selected for animal feed supplementation (vitamin D2 or D3, or 25(OH)D), baseline participant status and the bioaccessibility from the food matrix. Further research in the form of robust human clinical trials are required to explore the contribution of biofortified foods to vitamin D status.

A passive membrane system for on-line mass spectrometry reagent addition.

RATIONALE: Post-separation addition of chemical modifiers in liquid chromatography-mass spectrometry is widely used for improving ionization sensitivity and selectivity. This is typically accomplished using a post-column T-junction, which can result in sample dilution and imperfect mixing. We present a passive semi-permeable hollow fiber membrane approach for the addition of chemical modifiers that avoids these issues. METHODS: Model compounds were directly infused by flow injection to an electrospray ionization triple quadrupole mass spectrometer after passing through a polydimethylsiloxane hollow fiber membrane. Ionization enhancement reagents were introduced into the flowing stream by membrane permeation from aqueous solutions. Ionization enhancement from volatile acids and bases in positive and negative electrospray ionization was evaluated to assess the feasibility of this approach. RESULTS: The membrane-based apparatus resulted in relative ionization enhancement factors of up to 14×, depending upon the analyte, reagent, and ionization mode used. Ionization enhancement signal stability is reasonable (relative standard deviation of 5-7%) for extended periods from the same reagent solution, and minimal analyte dilution is observed. A proof-of-concept demonstration of the chromatographic "trifluoroacetic acid fix" strategy is presented. CONCLUSIONS: An on-line mass spectrometry ionization reagent addition method with potential post-chromatography reagent addition applications was developed using a hollow fiber polydimethylsiloxane membrane. This approach offers a promising alternative to traditional methods requiring additional hardware such as pumps and T-junctions that can result in sample dilution and imperfect reagent mixing.

Long-term supplementation with anthocyanin-rich or -poor Rubus idaeus berries does not influence microvascular architecture nor cognitive outcome in the APP/PS-1 mouse model of Alzheimer's disease.

Disruption of microvascular architecture is a common pathogenic mechanism in the progression of Alzheimer's disease (AD). Given the anti-angiogenic activity of berry (poly)phenols, we investigated whether long-term feeding of Rubus idaeus (raspberries) could ameliorate cerebral microvascular pathology and improve cognition in the APP/PS-1 mouse model of AD. Male C57Bl/6J mice (50 wild type, 50 APP/PS-1) aged 4-months were fed for 24-weeks, with a normal diet enriched with either 100 mg/day glucose (control diet) or supplemented with glucose and freeze-dried anthocyanin-rich (red) or -poor (yellow) raspberries (100 mg/day) and assessed/sampled post intervention. Cerebral microvascular architecture of wild-type mice was characterised by regularly spaced capillaries with uniform diameters, unlike APP/PS-1 transgenic mice which showed dysregulated microvascular architecture. Long-term feeding of raspberries demonstrated limited modulation of microbiota and no substantive effect on microvascular architecture or cognition in either mice model although changes were evident in endogenous cerebral and plasmatic metabolites.

Excretion by subjects on a low (poly)phenol diet of phenolic gut microbiota catabolites sequestered in tissues or associated with catecholamines and surplus amino acids.

Phenolic catabolites excreted by fasting subjects with a functioning colon and ileostomists on a low (poly)phenol diet have been investigated. Urine was collected over a 12 h fasting period after adherence to a low (poly)phenol diet for 36 h. UHPLC-HR-MS quantified 77 phenolics. Some were present in the urine of both groups in similar trace amounts and others were excreted in higher amounts by participants with a colon indicating the involvement of the microbiota. Most were present in sub- or low-µmol amounts, but hippuric acid dominated accounting on average for 60% of the total for both volunteer categories indicating significant production from sources other than non-nutrient dietary (poly)phenols. The potential origins of the phenolics associated with the low (poly)phenol diet, include endogenous catecholamines, surplus tyrosine and phenylalanine, and washout of catabolites derived from pre-study intakes of non-nutrient dietary (poly)phenols.

Persistent Immune Activation in Human Immunodeficiency Virus-Infected Pregnant Women Starting Combination Antiretroviral Therapy After Conception.

This study evaluated the impact of human immunodeficiency virus (HIV) and combination antiretroviral therapy (cART) on immune activation during pregnancy in a Zambian cohort of HIV-exposed but uninfected children followed up from birth. Activated CD8+ T cells (CD38+ and HLA-DR+) were compared among HIV-uninfected (n = 95), cART experienced HIV-infected (n = 111), and cART-naive HIV-infected (n = 21) pregnant women. Immune activation was highest among HIV-infected/cART-naive women but decreased during pregnancy. Immune activation HIV-infected women who started cART during pregnancy was reduced but not to levels similar to those in HIV-uninfected women. The effects of elevated maternal immune activation in pregnancy on subsequent infant health and immunity remain to be determined.

A direct mass spectrometry method for cannabinoid quantitation in urine and oral fluid utilizing reactive paper spray ionization.

A direct mass spectrometry method utilizing reactive paper spray ionization was developed for sensitive cannabinoid quantitation in biofluid matrices. The ca. 2-minute sample measurements used on-paper derivatization to significantly increase paper spray mass spectrometry (PS-MS) positive ion mode sensitivity while minimizing sample preparation steps. Calibrations demonstrate high linearity, with R2 > 0.99 for (-)-trans-Δ9-tetrahydrocannabinol (THC) in oral fluid and 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THC-COOH) in urine. The limit of detection and lower limit of quantitation were 0.78 and 10 ng mL-1 for THC in oral fluid and 1.3 and 10 ng mL-1 for THC-COOH in urine, respectively. THC-COOH levels measured by reactive PS-MS in seven spiked human urine samples showed bias of -9.4 to 5.9%, and percent difference values of -16.8 to 9.8% in comparison with a reference LC-MS method. Based upon the method simplicity, validation experiments, sensitivity, and rapidity, we conclude that reactive PS-MS has potential applications for rapid cannabinoid drug testing in urine and oral fluid.

Membrane Sampling Separates Naphthenic Acids from Biogenic Dissolved Organic Matter for Direct Analysis by Mass Spectrometry.

Oil sands process waters can release toxic naphthenic acids (NAs) into aquatic environments. Analytical techniques for NAs are challenged by sample complexity and interference from naturally occurring dissolved organic matter (DOM). Herein, we report the use of a poly(dimethylsiloxane) (PDMS) polymer membrane for the on-line separation of NAs from DOM and use direct infusion electrospray ionization mass spectrometry to yield meaningful qualitative and quantitative information with minimal sample cleanup. We compare the composition of membrane-permeable species from natural waters fortified with a commercial NA mixture to those derived from weak anion exchange solid-phase extraction (SPE) using high-resolution mass spectrometry. The results show that SPE retains a wide range of carboxylic acids, including biogenic DOM, while permeation through PDMS was selective for petrogenic classically defined NAs (CnH2n+zO2). A series of model compounds (log Kow ∼1-7) were used to characterize the perm-selectivity and reveal the separation is based on hydrophobicity. This convenient sample cleanup method is selective for the O2 class of NAs and can be used prior to conventional analysis or as an on-line analytical strategy when coupled directly to mass spectrometry.

MASS SPECTROMETRY ANALYSIS OF DRUGS OF ABUSE: CHALLENGES AND EMERGING STRATEGIES.

Mass spectrometry has been the "gold standard" for drugs of abuse (DoA) analysis for many decades because of the selectivity and sensitivity it affords. Recent progress in all aspects of mass spectrometry has seen significant developments in the field of DoA analysis. Mass spectrometry is particularly well suited to address the rapidly proliferating number of very high potency, novel psychoactive substances that are causing an alarming number of fatalities worldwide. This review surveys advancements in the areas of sample preparation, gas and liquid chromatography-mass spectrometry, as well as the rapidly emerging field of ambient ionization mass spectrometry. We have predominantly targeted literature progress over the past ten years and present our outlook for the future. © 2020 Periodicals, Inc. Mass Spec Rev.

Endocannabinoids, endocannabinoid-like molecules and their precursors in human small intestinal lumen and plasma: does diet affect them?

PURPOSE: To determine the small intestinal concentration of endocannabinoids (ECs), N-acylethanolamines (NAEs) and their precursors N-acylphosphatidylethanolamines (NAPEs) in humans. To identify relationships between those concentrations and habitual diet composition as well as individual inflammatory status. METHODS: An observational study was performed involving 35 participants with an ileostomy (18W/17M, aged 18-70 years, BMI 17-40 kg/m2). Overnight fasting samples of ileal fluid and plasma were collected and ECs, NAEs and NAPEs concentrations were determined by LC-HRMS. Dietary data were estimated from self-reported 4-day food diaries. RESULTS: Regarding ECs, N-arachidonoylethanolamide (AEA) was not detected in ileal fluids while 2-arachidonoylglycerol (2-AG) was identified in samples from two participants with a maximum concentration of 129.3 µg/mL. In contrast, mean plasma concentration of AEA was 2.1 ± 0.06 ng/mL and 2-AG was 4.9 ± 1.05 ng/mL. NAEs concentrations were in the range 0.72-17.6 µg/mL in ileal fluids and 0.014-0.039 µg/mL in plasma. NAPEs concentrations were in the range 0.3-71.5 µg/mL in ileal fluids and 0.19-1.24 µg/mL in plasma being more abundant in participants with obesity than normal weight and overweight. Significant correlations between the concentrations of AEA, OEA and LEA in biological fluids with habitual energy or fat intakes were identified. Plasma PEA positively correlated with serum C-reactive protein. CONCLUSION: We quantified ECs, NAEs and NAPEs in the intestinal lumen. Fat and energy intake may influence plasma and intestinal concentrations of these compounds. The luminal concentrations reported would allow modulation of the homeostatic control of food intake via activation of GPR119 receptors located on the gastro-intestinal mucosa. CLINICAL TRIAL REGISTRY NUMBER AND WEBSITE: NCT04143139; www.clinicaltrials.gov .

Sulforaphane-enriched extracts from glucoraphanin-rich broccoli exert antimicrobial activity against gut pathogens in vitro and innovative cooking methods increase in vivo intestinal delivery of sulforaphane.

PURPOSE: Studies on broccoli (Brassica oleracea var. italica) indicate beneficial effects against a range of chronic diseases, commonly attributed to their bioactive phytochemicals. Sulforaphane, the bioactive form of glucoraphanin, is formed by the action of the indigenous enzyme myrosinase. This study explored the role that digestion and cooking practices play in bioactivity and bioavailability, especially the rarely considered dose delivered to the colon. METHODS: The antimicrobial activity of sulforaphane extracts from raw, cooked broccoli and cooked broccoli plus mustard seeds (as a source myrosinase) was assessed. The persistence of broccoli phytochemicals in the upper gastrointestinal tract was analysed in the ileal fluid of 11 ileostomates fed, in a cross-over design, broccoli soup prepared with and without mustard seeds. RESULTS: The raw broccoli had no antimicrobial activity, except against Bacillus cereus, but cooked broccoli (with and without mustard seeds) showed considerable antimicrobial activity against various tested pathogens. The recovery of sulforaphane in ileal fluids post soup consumption was < 1% but the addition of mustard seeds increased colon-available sulforaphane sixfold. However, when sulforaphane was extracted from the ileal fluid with the highest sulforaphane content and tested against Escherichia coli K12, no inhibitory effects were observed. Analysis of glucosinolates composition in ileal fluids revealed noticeable inter-individual differences, with six "responding" participants showing increases in glucosinolates after broccoli soup consumption. CONCLUSIONS: Sulforaphane-rich broccoli extracts caused potent antimicrobial effects in vitro, and the consumption of sulforaphane-enriched broccoli soup may inhibit bacterial growth in the stomach and upper small intestine, but not in the terminal ileum or the colon.

Direct, Isomer-Specific Quantitation of Polycyclic Aromatic Hydrocarbons in Soils Using Membrane Introduction Mass Spectrometry and Chemical Ionization.

Polycyclic aromatic hydrocarbons (PAHs) are routinely screened for in soils, where quantitation of structural isomers is critical due to varying toxicity within PAH isomer classes. While chromatographic methods provide isomer resolution, such strategies are cost and time intensive. To address these challenges, we present condensed phase membrane introduction mass spectrometry using liquid electron ionization/chemical ionization (CP-MIMS-LEI/CI) as a direct mass spectrometry technique that provides rapid, quantitative results for PAH isomer measurements in soil samples. A methanol acceptor phase is flowed through a probe-mounted polydimethylsiloxane hollow fiber membrane directly immersed into a dichloromethane/soil slurry. PAHs and dichloromethane co-permeate the membrane into the acceptor solvent, whereas particulates and charged matrix components remain in the sample. A nanoflow of the membrane permeate is then directly infused into a LEI/CI interfaced triple quadrupole mass spectrometer. Diagnostic PAH adduct ions were formed at either M + 45 ([M + CH2Cl + CH3OH-HCl]+) or M + 47 ([M + CHCl2-HCl]+). This allowed the development of specific MS/MS transitions for individual PAH isomers. These transitions were subsequently used for the direct analyses of PAHs in real soils where CP-MIMS-LEI/CI was shown to be rapid (15 soil samples/h) and sensitive (ng/g level detection limits). CP-MIMS-LEI/CI results compared well to those obtained using GC-MS (average percent difference of -9% across 9 PAHs in 8 soil samples), presenting a compelling argument for direct, quantitative screening of PAHs in soils by CP-MIMS-LEI/CI, particularly given the simple workflow and short analytical duty cycle.

Antioxidant and antigenotoxic activities of Ginkgo biloba L. leaf extract are retained after in vitro gastrointestinal digestive conditions.

PURPOSE: The recognized biological properties of Ginkgo biloba extracts potentiate their utilization as an ingredient for functional foods. However, the digestive conditions can affect the chemical composition of the extracts and consequently their biological properties, which can lead to food safety problems. Thus, the impact of in vitro-simulated upper gastrointestinal tract digestion on the chemical composition and bioactivity of Ginkgo biloba leaf extract (GBE) was evaluated. METHODS: Physicochemical conditions of human digestion were simulated in vitro, and its impact on the chemical composition of GBE was investigated by electrospray ionization-mass spectrometry. The persistence of bioactivity was investigated by subjecting GBE and the in vitro digested extract (DGBE) to the same methodology. Antioxidant properties were assessed using 2',7'-dichlorofluorescein diacetate to measure the intracellular oxidation of Schizosaccharomyces pombe cells pre-incubated with GBE or DGBE and exposed to H2O2. Antigenotoxicity was tested by comet assay in HT-29 colon cancer cells pre-incubated with GBE or DGBE and challenged with H2O2. RESULTS: The chemical analysis revealed a considerable change in chemical composition upon digestion. Pre-incubation with GBE or DGBE attenuated the H2O2-imposed intracellular oxidation in wild-type S. pombe cells, unlike the oxidative stress response-affected mutants sty1 and pap1, and decreased H2O2-induced DNA damage in HT-29 cells. The extracts did not induce toxicity in these eukaryotic models. CONCLUSION: The chemical composition of GBE was affected by in vitro digestion, but the antioxidant and antigenotoxic activities persisted. Therefore, G. biloba extract may be suitable for use as food additive and contribute to a healthy colon.

Modest improvement in CVD risk markers in older adults following quinoa (Chenopodium quinoa Willd.) consumption: a randomized-controlled crossover study with a novel food product.

PURPOSE: To investigate the effect of consuming quinoa biscuits on markers of CVD risk over 4 weeks in free-living older adults. METHODS: A randomized-controlled, double-blind crossover trial was conducted in which consenting healthy adults aged 50-75 years (n = 40) consumed 15 g quinoa biscuits (60 g quinoa flour/100 g) or control iso-energetic biscuits (made using wheat flour) daily for 28 consecutive days (4 weeks), in addition to their normal diet. Following a 6-week washout, participants consumed the alternate biscuit for a final 4 weeks. Anthropometry and fasted blood samples were obtained before and after each intervention period. RESULTS: At the beginning of the trial, mean ± SD total cholesterol concentrations were 6.02 ± 1.22 mmol/L (3.7-9.2 mmol/L); 33 participants (82.5%) had high cholesterol (> 5 mmol/L). No participants were lost to follow-up and there were no changes in habitual dietary intakes or levels of physical activity between each 4-week intervention period. Significantly greater decreases in total and LDL cholesterol concentrations (- 0.30 ± 0.58 and - 0.25 ± 0.38 mmol/L, respectively), TC: HDL ratio (- 0.11 ± 0.30), weight (- 0.61 ± 0.89 kg) and BMI (- 0.22 ± 0.34 kg/m2) were apparent following consumption of the quinoa versus control biscuits (all P < 0.05). Changes in triglycerides, HDL cholesterol, or PUFA or CRP concentrations were not significant between treatment groups. CONCLUSION: Consumption of novel quinoa biscuits produced small, but favorable changes in body weight, BMI, and circulating cholesterol concentrations, all of which may contribute to lowered CVD risk in older adults.

Phenyl-γ-valerolactones and phenylvaleric acids, the main colonic metabolites of flavan-3-ols: synthesis, analysis, bioavailability, and bioactivity.

Covering: 1958 to June 2018 Phenyl-γ-valerolactones (PVLs) and their related phenylvaleric acids (PVAs) are the main metabolites of flavan-3-ols, the major class of flavonoids in the human diet. Despite their presumed importance, these gut microbiota-derived compounds have, to date, in terms of biological activity, been considered subordinate to their parent dietary compounds, the flavan-3-ol monomers and proanthocyanidins. In this review, the role and prospects of PVLs and PVAs as key metabolites in the understanding of the health features of flavan-3-ols have been critically assessed. Among the topics covered, are proposals for a standardised nomenclature for PVLs and PVAs. The formation, bioavailability and pharmacokinetics of PVLs and PVAs from different types of flavan-3-ols are discussed, taking into account in vitro and animal studies, as well as inter-individual differences and the existence of putative flavan-3-ol metabotypes. Synthetic strategies used for the preparation of PVLs are considered and the methodologies for their identification and quantification assessed. Metabolomic approaches unravelling the role of PVLs and PVAs as biomarkers of intake are also described. Finally, the biological activity of these microbial catabolites in different experimental models is summarised. Knowledge gaps and future research are considered in this key area of dietary (poly)phenol research.

Direct Analysis of Polyaromatic Hydrocarbons in Soil and Aqueous Samples Using Condensed Phase Membrane Introduction Tandem Mass Spectrometry with Low-Energy Liquid Electron Ionization.

Polyaromatic hydrocarbons (PAHs) are listed as priority pollutants by the United States Environmental Protection Agency (U.S. EPA). PAH-contaminated samples often require extensive sample cleanup before analysis, with the method used dependent upon the sample matrix. We present condensed phase membrane introduction mass spectrometry with liquid electron ionization (CP-MIMS-LEI) as a sensitive and universal technique that can directly analyze both aqueous and soil samples for PAHs without the need for sample clean up or instrumental modifications for different matrixes. The method uses a semipermeable hollow fiber membrane immersion probe to transfer analytes from complex samples into a solvent acceptor phase that is directly entrained at nanoliter/min flows to an LEI-interfaced mass spectrometer. The resulting aerosol is desolvated under vacuum leading to analyte vaporization and subsequent electron ionization. Electron energy and LEI vaporization capillary position were examined and optimized for PAHs. The CP-MIMS probe was directly immersed in complex aqueous matrixes, demonstrating low nanogram per liter PAH detection limits and response times of ≤1.6 min. For soil sample analysis, 2-propanol was found to be the optimal PAH sampling solvent. Soil samples were briefly sonicated in 2-propanol, followed by direct CP-MIMS measurement. Soil sample throughput was ca. 15 samples/h, with PAH quantitation successful at microgram per kilogram levels. The workflow is remarkably simple, fast, green, and leads to reproducible results that enable high-throughput screening of heterogeneous soil samples.