Miniaturized paper-based analytical device for the portable analysis of phyto-cannabinoids in plant and oral fluids.

In this work, a low-cost and eco-friendly paper-based analytical device (PAD) method is described for the determination of phyto-cannabinoids in cannabis and oral fluids based on a simple colorimetric reaction. The PAD was able to distinguish tetrahydrocannabinol (THC)- and cannabidiol (CBD)-rich plant samples by using 4-aminophenol (4-AP) and later on to quantify total phyto-cannabinoid content (THC + CBD + CBN) in plant and oral fluids by using the Fast Corinth V reagent. The chemical and physical properties regarding paper type and reagent concentration in the PAD were optimized to achieve the best analytical performance. After that, analytical features were obtained, including a linear range of 0.01-0.1 mg mL-1, a limit of detection (LOD) of 0.003 mg mL-1, and a suitable precision, expressed as relative standard deviation (RSD) lower than 10%. Furthermore, no significant interferences were observed in colorimetric reactions when tea, herbs, and drug samples were analyzed. Additionally, the PAD proved color stability up to 1 month after the sampling at 25 °C. The developed PAD was suitable for determining total phyto-cannabinoid content in plants and oral fluids, obtaining good results compared to GC-MS. Overall, this method showed good reliability resulting in an operational on-site device for drug monitoring.

Implementation of remote sensing algorithms to estimate TOC, Chl-a, and TDS in a tropical water body; Sanalona reservoir, Sinaloa, Mexico.

The present study implements a methodology to estimate water quality values using statistical tools and remote sensing techniques in a tropical water body Sanalona. Linear regression models developed by Box-Cox transformations and processed data from LANDSAT-8 imagery (bands) were used to estimate TOC, TDS, and Chl-a of the Sanalona reservoir from 2013 to 2020 at five sampling sites measured every 6 months. A band discriminant analysis was carried out to statistically fit and optimize the proposed algorithms. Coefficients of determination beyond 0.9 were obtained for these water quality parameters (r2TOC = 0.90, r2TDS = 0.95, and r2Chl-a = 0.96). A comparison between the estimated and observed water quality was carried out using different data for validation. The validation of the models showed favorable results with R2TOC = 0.8525, R2TDS = 0.8172, and R2Chl-a = 0.9256. The present study implemented, validated, and compared the results obtained by using an ordered and standardized methodology proposed for the estimation of TOC, TDS, and Chl-a values based on water quality parameters measured in the field and using satellite images.

Micro-paper-based analytical device decorated with metal-organic frameworks for the assay of synthetic cannabinoids in oral fluids coupled to ion mobility spectrometry.

A new concept of paper-based device has been developed combining the advantages of cellulose supports and the rich surface chemistry of metal-organic frameworks (MOFs). The composite, named as NH2-UiO-66@paper, has been developed for the isolation of synthetic cannabinoid receptor agonists (SCRAs) in oral fluids, trying to mimic the interactions of those compounds with the human CB1R and CB2R receptors, mainly governed by hydrogen bonding and π-interactions with serine and histidine residues. MOF selection (UiO-66) and functionalization of the ligand (2-aminoterephthalic acid) has been done according to the following criteria: (i) water stability of the selected MOF, and (ii) promoting appropriate interactions with SCRAs due to the MOF nature. NH2-UiO-66@paper composite has been characterized in depth and the results confirmed that the material is stable at the temperature selected for thermal desorption (230 °C). Furthermore, the developed method provided appropriate precision values (RSD < 12%) and a limit of detection as low as 10 ng using ion mobility spectrometry as analytical technique. Lastly, the method has been successfully applied to the isolation of several synthetic cannabinoids from oral fluids. This method claims to be an interesting approach for expanding the combination of MOFs with sustainable support and represents a promising alternative to sophisticated and non-portable systems due to the negligible sample treatment required and the simplicity of the operation, which can be applied with screening purposes.

Skin Permeation of Hazardous Compounds of Tobacco Smoke in Presence of Antipollution Cosmetics.

Negative health effects of active and passive smokers have been widely described, but the effect of tobacco smoke on the skin has been less explored. In this study, an analytical methodology has been developed to evaluate the dermal permeation of hazardous compounds present in tobacco smoke, using an exposition chamber to simulate finite and infinite smoking conditions, in vitro vertical Franz diffusion cells, and Strat-M® membranes as human skin simulants. Moreover, the antipollution effect of three cosmetics has been evaluated, showing a significant efficacy to reduce dermal permeation of hazardous tobacco-smoke compounds such as of nicotine and aromatic hydrocarbons.

Skin Penetration of Hazardous Air Pollutants in Presence of Antipollution Cosmetics.

Different a n tipollution products have recently irrupted the market to answer current health concerns related to air contamination. Thus, the development of methodologies for the appropriate evaluation of the efficacy of these products is needed. In this study, an appropriate analytical methodology has been developed and validated for the evaluation of the effectiveness of antipollution cosmetic products against the dermal absorption of different hazardous air pollutants (HAPs). In vitro vertical Franz diffusion cells and Strat-M® as human skin simulants have been used to assess the effectivity of antipollution cosmetic products. An exposition chamber, with a fixed and constant concentration of HAPs, including benzene, toluene, ethylbenzene, and xylene isomers, chlorobenzene, nitrobenzene, haloalkanes, and polycyclic aromatic hydrocarbons, has been designed and made to simulate contaminated atmospheres. The efficacy of antipollution cosmetic products has been evaluated using a multi-pollutant approach, representing a more stringent situation. Diffusion parameters, including flux and lag time, have been calculated for HAPs in the presence of cosmetic samples, using 2 mg product per cm2, and in control tests. The behavior of HAPs followed Fick's first law, allowing the calculation of diffusion parameters. Antipollution effectiveness is demonstrated by statistical evaluation of the diffusion parameters obtained for controls and cosmetics samples. So, a reduction in flux values and an increase in lag times imply an appropriate antipollution effectiveness.

Development of immunosorbents for the analysis of forchlorfenuron in fruit juices by ion mobility spectrometry.

The advantages of using smart materials as immunosorbents in the analysis of complex matrices by ion mobility spectrometry (IMS) have been highlighted in this study. A novel analytical method has been proposed for the sensitive, selective, and fast determination of residues of the plant growth regulator forchlorfenuron in fruit juices. Three different monoclonal antibodies (s3#22, p2#21, and p6#41) were employed for the production of immunosorbents, based on Sepharose gel beads, which were characterized in terms of loading capacity, solvent resistance, and repeatability for its use in solid-phase extraction (SPE). Immunosorbents that were prepared with antibody p6#44 provided the best performance, with a loading capacity of 0.97 µg, a 10% (v/v) 2-propanol tolerance, and a reusability of at least eight uses. The SPE procedure involved the use of a column with 0.15 g Sepharose beads, containing 0.5 mg antibody, which was loaded to 20 mL of the sample, washed with 2 mL of water plus 2 mL of 10% (v/v) 2-propanol, and eluted with 2 mL of 2-propanol. The cleaned extract was directly analyzed by IMS, giving a limit of detection of 2 µg L-1 with a relative standard deviation of 7.6%. Trueness was assessed by the analysis of blank grape and kiwifruit juice samples spiked with forchlorfenuron concentrations from 10 to 400 µg L-1, with recoveries from 80 to 115%. The analytical performance of the proposed immunosorbent was compared with conventional extraction and cleanup methods, such as QuEChERS and C18-based SPE, giving the cleanest extracts for accurate determinations of forchlorfenuron by IMS. Graphical abstract ᅟ.

Hard Cap Espresso Machines in Analytical Chemistry: What Else?

A hard cap espresso machine has been used in combination with liquid chromatography with molecular fluorescence detection for the determination of polycyclic aromatic hydrocarbons (PAHs) from contaminated soils and sediments providing appropriate extraction efficiencies and quantitative results. Naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, chrysene, benz[b]fluoranthene, benz[k]fluoranthene, benz[a]pyrene, dibenz[a,h]anthracene, benz[ghi]perylene, and indeno[1,2,3-cd]pyrene were used as target compounds. It should be mentioned that the pairs benz[a]anthracene-chrysene and dibenz[a,h]anthracene-benz[ghi]perylene peaks coelute under the employed chromatographic conditions; thus, those compounds were determined together. PAHs were extracted from 5.0 g of soil, previously homogenized, freeze-dried, and sieved to 250 µm, with 50 mL of 40% (v/v) acetonitrile in water at a temperature of 72 ± 3 °C. The proposed procedure is really fast, with an extraction time of 11 s, and it reduces the required amount of organic solvent to do the sample preparation. The obtained limit of detection for the evaluated PAHs was from 1 to 38 µg kg(-1). Recoveries were calculated using clean soils spiked with 100, 500, 1000, and 2000 µg kg(-1) PAHs with values ranging from 81 to 121% and good precision with relative standard deviation values lower than 30%. The method was validated using soil and sediment certified reference materials and also using real samples by comparison with ultrasound-assisted extraction, as reference methodology, obtaining statistically comparable results. Thus, the use of hard cap espresso machines in the analytical laboratories offers tremendous possibilities as low cost extraction units for the extraction of solid samples.

Determination of 3,4-methylenedioxypyrovalerone (MDPV) in oral and nasal fluids by ion mobility spectrometry.

A fast and sensitive methodology has been developed for the evaluation of the 3,4-methylenedioxypyrovalerone (MDPV) consumed. Based on ion mobility spectrometry (IMS), MDPV was directly determined in nasal fluids with a limit of detection (LOD) in the order of 22 ng mL(-1), which corresponds to an absolute amount of 33 ng of MDPV per swab. MDPV was also determined after liquid-liquid microextraction (LLME) in oral fluids to avoid matrix effects, obtaining a LOD value of 4.4 ng mL(-1) in oral fluid samples. The IMS spectrum for MDPV exhibited a peak with K0 = 1.210 ± 0.005 cm(2)V(-1) s(-1) at a drift time of 14.62 ms, the total analysis time being 4.5 min per oral fluid and 1.5 min per nasal fluid sample. Samples must be analyzed within 24 h following collection and dissolution in 2-propanol, based on the complementary stability studies.

Highly selective solid-phase extraction sorbents for chloramphenicol determination in food and urine by ion mobility spectrometry.

Different highly selective sorbents have been evaluated for the treatment of food and biological samples to determine chloramphenicol residues by ion mobility spectrometry (IMS). Combination of a selective solid-phase extraction (SPE) and dispersive liquid-liquid microextraction allowed a highly sensitive determination of chloramphenicol in water, milk, honey, and urine samples. The performance of selective SPE supports such as immunoaffinity chromatography (IAC) and molecular imprinted polymers (MIP) have been compared in terms of selectivity, sensitivity, trueness, precision, and reusability. Quantitative recoveries were obtained for chloramphenicol residues, ranging from 91 to 123 % for water, from 99 to 120 % for skimmed milk, and from 95 to 124 % for urine using IAC-IMS and MIP-IMS methods. Quantitative recoveries (from 88 to 104 %) were also achieved for honey samples using IAC-IMS, but low recoveries were obtained using MIP-IMS. The limit of quantification was set at 0.1 µg L-1 which is lower than the minimum required performance limit established by the EU. The proposed methodology is a simple and cost affordable alternative to chromatography methods for the highly sensitive and selective analysis of chloramphenicol residues in food and urine. Graphical Abstract Scheme for chloramphenicol determination by selective solid-phase extraction and ion mobility spectrometry.

Detection of tetrahydrocannabinol residues on hands by ion-mobility spectrometry (IMS). Correlation of IMS data with saliva analysis.

Ion-mobility spectroscopy (IMS) was evaluated as a high-throughput, cheap, and efficient analytical tool for detecting residues of tetrahydrocannabinol (THC) on hands. Regarding the usefulness of hand residues as potential samples for determining THC handling and abuse, we studied the correlation between data obtained from cannabis consumers who were classified as positive after saliva analysis and from those who were classified as positive on the basis of the information from hand-residue analysis. Sampling consisted of wiping the hands with borosilicate glass microfiber filters and introducing these directly into the IMS after thermal desorption. The possibility of false positive responses, resulting from the presence of other compounds with a similar drift time to THC, was evaluated and minimised by applying the truncated negative second-derivative algorithm. The possibility of false negative responses, mainly caused by competitive ionisation resulting from nicotine, was also studied. Graphical abstract THC residues: from hands to analytical signals.

Noninvasive double confirmation of cocaine abuse.

A double confirmation procedure, based on the combined application of Ion Mobility Spectrometry (IMS) and Infrared Spectroscopy (IR), has been developed for the noninvasive unambiguous identification of cocaine consume. The use of nasal mucus as a biological specimen for cocaine abuse confirmation has been proposed as an alternative to the use of blood and urine due to its noninvasive character and the presence of the parent compound instead of its metabolites. Sampling conditions, interferences caused by cutting agents and other substances, and limits of identification (LOI) and confirmation (LOC) have been deeply evaluated. The procedure combines the high sensitivity of the IMS to identify positive samples with the high selectivity of the IR procedure to confirm positive results. Thus, the proposed two tier method has been applied to the detection and identification of cocaine in the nasal mucus of different individuals, consumers, and nonconsumers, providing results comparable with those obtained by a reference procedure.

Development and validation of an analytical method for the simultaneous determination of 12 ergot, 2 tropane, and 28 pyrrolizidine alkaloids in cereal-based food by LC-MS/MS.

Alkaloids are naturally occurring compounds containing basic nitrogen atoms. They are biosynthesized mainly by plants but also by some fungi species. Many alkaloids are toxic to humans and animals, and they have been classified as food contaminants. Among them, ergot, tropane, and pyrrolizidine alkaloids have maximum levels in foods, established by the Commission Regulation (EU) 2023/915. In this study, an analytical method was successfully developed and validated for the simultaneous determination of 42 ergot, tropane, and pyrrolizidine alkaloids and their N-oxides in cereal-based food. The method includes QuEChERS-based extraction followed by liquid chromatography coupled with tandem mass spectrometry. The proposed method was validated providing recoveries ranging from 71 to 119 %, intra- and inter-day precision lower than 19 %, and limits of quantification between 0.5 and 1.0 µg kg-1. Finally, the analysis of reference materials coming from FAPAS proficiency tests demonstrated the suitability for purpose of the methodology (z-scores < 2). Nine cereal-based products samples were analyzed of which ergot alkaloids were detected in two of them, while one sample showed the presence of three pyrrolizidine alkaloids.

Metal-organic frameworks as promising solid-phase sorbents for the isolation of third-generation synthetic cannabinoids in biological samples.

In this work, metal-organic frameworks (MOFs) were used for the first time as solid-phase extraction (SPE) sorbents for the isolation of synthetic cannabinoids (SCs) from oral fluids and subsequently quantified by LC-fluorescence detection (FLD). In this context, different MOF families were synthesized and tested under SPE mode. UiO-66 was the family selected, being the amino functionalized (NH2-UiO-66) the best candidate in terms of extraction performance. After the method optimization, several analytical parameters of interest were obtained, reaching limits of detection (LODs) as low as 0.6-0.8 µg L-1 and precision values (expressed as RSD) lower than 10.6%. The developed method was successfully applied to the determination of 8 SCs in different oral fluids at three spiked levels with recoveries between 67 and 114%. This method claims to be a real alternative for screening purposes, being a cost-effective procedure due to the price of the sorbent (<0.5 €/cartridge) and its recyclability (up to 12 uses), among others good features.

Ion mobility spectrometry for monitoring diamine oxidase activity.

The capability of IMS for the determination of kinetics in complex enzyme systems with reduced v(max) values has been demonstrated with the example of diamine oxidase (DAO). Michaelis-Menten and Lineweaver-Burk plots were obtained for the enzyme catalyzed putrescine oxidation and calculations of the kinetic parameters have been performed and compared with previously published values. The IMS procedure provided a limit of detection of 200 pg mL(-1) for putrescine, a limit of quantification of 667 pg mL(-1), a precision of 5.9%, and an analysis frequency of 40 s, which are analytical characteristics appropriate to perform label-free enzyme studies. Additionally, pseudo-competitive inhibition of the putrescine oxidation due to other diamines binding to the free enzyme has been evaluated. Moreover, the mass-mobility correlation curve of diamines based on the calculated mobilities of the studied analytes and data previously reported for cadaverine, serotonin and tryptamine was modelled. The analytical method could be used as an additional complementary tool for the existing drug discovery method, for the search of DAO activators; molecules that displace the substrate from the second site of DAO, but does not interfere with the catalytic function of the first site.

Metabolism of third generation synthetic cannabinoids using zebrafish larvae.

Synthetic cannabinoids are the second largest group of new psychoactive substances reported by the United Nations Office on Drugs and Crime in the last decade and case reports bring attention to its high potency effects and its severe toxicity, including fatalities. Moreover, synthetic cannabinoids are usually entirely metabolized and metabolic pathways for many new generation synthetic cannabinoids are still unknown. In this study, the metabolism of five third generation synthetic cannabinoids was evaluated using zebrafish (Danio rerio) larvae as 24-h in vivo model studied within 5 days after fertilization. The studied synthetic cannabinoids were MMB-CHMICA, ADB-CHMICA, ADB-CHMINACA, MDMB-CHMCZCA, and NNL-3, and the respective metabolites were identified by liquid chromatography-high resolution tandem mass spectrometry. Eleven, six, fourteen, eleven, and four metabolites were identified for MMB-CHMICA, ADB-CHMICA, ADB-CHMINACA, MDMB-CHMCZCA, and NNL-3, respectively, and metabolic pathways have been proposed. The use of zebrafish larvae, with a high degree of physiological and genetic homology to humans, is an emerging tool very useful for the identification of metabolic pathways of psychoactive substances. Results obtained in this study compared well with metabolites obtained previously for the same target molecules or structural analogous after in vitro incubation with human or rat hepatocytes. Thus, potential biomarkers for the evaluated compounds are the O-demethylated metabolite for MMB-CHMICA; the oxidative deamination to hydroxyl metabolite for ADB-CHMICA; hydroxyl metabolites at cyclohexylmethyl, tert-butyl, and indazole moieties for ADB-CHMINACA; hydroxyl metabolites at carbazole core, tert-butyl, or cyclohexylmethyl tail moieties for MDMB-CHMCZCA; and amide hydrolyzed, defluorinated, and dihydroxilated metabolite for NNL-3.

Analysis of drugs including illicit and new psychoactive substances in oral fluids by gas chromatography-drift tube ion mobility spectrometry.

In this study, a gas chromatograph (GC) has been coupled to a drift tube ion mobility spectrometer (IMS) in order to develop an analytical procedure for the determination of psychoactive substances in oral fluids. Working parameters, including the GC-IMS interface ones, were adjusted in order to obtain sensitive and robust signals. A volume of 500 µL of oral fluid was extracted with 250 µL chloroform and, after centrifugation, were injected into the GC-IMS system. Amphetamine, methylone, α-PVP, ketamine, lidocaine, MPHP, cocaine, THJ-2201, and 5F-ADB were employed as model compounds, providing limits of detection from 6 to 15 µg L-1 and recoveries from 70 to 115% for field oral fluids spiked with target analytes at 250, 500, and 600 µg L-1. Moreover, two oral fluid certified reference materials were analysed by the proposed GC-IMS based methodology with obtained relative percentage errors lower than 8.4%, being the proposed GC-IMS procedure a reliable, selective, and sensitive technique for the determination of psychoactive substances in oral fluids.

Two constructed wetlands within a Mediterranean natural park immersed in an agrolandscape reduce most heavy metal water concentrations and dampen the majority of pesticide presence.

The water concentrations of 12 heavy and other metals/metalloids were analyzed seasonally along two horizontal-flow constructed wetlands (CWs) (Tancat Mília-TM and Tancat l'Illa-TLI) located within the Mediterranean Albufera de València Natural Park during 2020-2021. A wide-scope screening of pesticides present in waters was also performed. The two CWs were created to improve water quality and increase biodiversity. They currently receive effluent waters from two different tertiary-treatment wastewater plants, and the water flows along the CWs before being discharged into the main lagoon and a smaller lagoon in TM and TLI, respectively. TLI manages to reduce (Mn) or maintain the concentration of most of the studied elements (Zn, Ni, Hg, Cr, Fe Cd, Cu) at the same level as outside (67%). Only Al, Pb, B, and As remain at a higher concentration. TM also reduces Zn and Cu and keeps the concentration of Cr, Cd, and Hg (representing 42%). Al, Pb, B, and As remain at higher concentrations, as in TLI, but Ni, Fe, and Mn are also at higher concentrations. Although both CWs vary in their ability to remove elements, no risks to human health or the environment have been detected due to the low metal concentration in their outlets, all of them (except Hg) below the legal limits for environmental quality in the European Union. With the detection of 71 compounds in water in each CW area (26 herbicides, 26 insecticides, and 19 fungicides in TLI, and 29 herbicides, 23 insecticides, and 19 fungicides in TM), we also provide evidence of the impact of pesticides, which depends on the application method (helicopter, tractor), originated from areas with high agricultural pressure (chiefly rice crops) on systems (mainly TM) created to preserve biodiversity. Nevertheless, both systems provide crucial environmental services in water quality in this agrolandscape.

Determination of pyrimidine and purine bases by reversed-phase capillary liquid chromatography with at-line surface-enhanced Raman spectroscopic detection employing a novel SERS substrate based on ZnS/CdSe silver-quantum dots.

We have developed a new SERS substrate based on the reduction of silver nitrate in the presence of ZnS-capped CdSe quantum dots. This substrate showed higher sensitivities as compared to a hydroxylamine-reduced silver sol. On the basis of this new substrate, at-line SERS detection was coupled with capillary liquid chromatography (cap-LC) for the separation and selective determination of pyrimidine and purine bases. For this purpose, wells of a dedicated microtiter plate were loaded with 20 µL of the SERS substrate and placed on an automated x,y translation stage. A flow-through microdispenser capable of ejecting 50 pL droplets, at a frequency 100 Hz, was used as the interface to connect the cap-LC system to the wells loaded with SERS substrate. A detailed study of the dependence of both the separation and the surface-enhanced Raman spectra of each base on the pH was performed to optimize the system for maximum sensitivity and selectivity. Highly satisfactory analytical figures of merit were obtained for the six investigated bases (cytosine, xanthine, hypoxanthine, guanine, thymine, and adenine) with detection limits ranging between 0.2 and 0.3 ng injected on the capillary LC column, and the precisions were in the range of 3.0-6.3%.

Dual mixed-mode poly (vinylpyridine-co-methacrylic acid-co-ethylene glycol dimethacrylate)-based sorbent for acidic and basic drug extraction from oral fluid samples.

In this study, a dual mixed-mode polymer sorbent was prepared via one-step thermally initiated polymerization of 4-vinylpyridine (VP), methacrylic acid (MAA) and ethylene glycol dimethacrylate (EGDMA) for the solid-phase extraction (SPE) of basic and acidic drugs. The use of VP and MAA as ionizable functional monomers allowed the tailoring of ion-exchange and hydrophobic features of the polymer. The obtained polymer was characterized by Fourier-transform infrared spectroscopy and scanning electron microscopy. Next, the retention behavior of dual mixed-mode polymer towards basic and acidic drugs was investigated. Moreover, the practical capability of this novel material was tested for the extraction of relevant drugs such as cocaine, 3-methylmethcathinone, and diazepam in oral fluid samples. Recovery values (at different spiked levels in blank oral fluid samples), ranging from 69 to 99%, and limits of detection (LODs), between 0.10 and 0.25 µg L-1, were obtained.

Determination of Third-Generation Synthetic Cannabinoids in Oral Fluids.

A procedure has been developed for the determination of third-generation synthetic cannabinoids in oral fluid samples by using a semi-automated microextraction by packed sorbent (MEPS) procedure and gas chromatography-mass spectrometry (GC-MS) determination. Five synthetic cannabinoids were employed as model compounds 5F-ADB, MMB-CHMICA, THJ-2201, CUMYL-4CN-BINACA and MDMB-CHMCZCA. The most adequate operative conditions for MEPS were evaluated giving quantitative recoveries, from 89 to 124%, in synthetic and field saliva samples spiked with 125 and 250 µg/L of the studied cannabinoids, with the exception of MDMB-CHMCZCA in field saliva samples that provided slightly lower recoveries from 62 to 66%. A high sensitivity was obtained for the proposed MEPS-GC-MS procedure with limits of detection from 10 to 20 µg/L. The obtained results demonstrate the high potential of MEPS-GC-MS combination for semi-automated, selective and sensitive determination of synthetic cannabinoids in oral fluid samples.