Fast liquid chromatography-tandem mass spectrometry method for the simultaneous determination of phytocannabinoids in oily based preparations.

The reported method aims to be a powerful aid for the simultaneous determination of tetrahydrocannabinol (THC), cannabidiol (CBD), cannabinol (CBN), cannabigerol (CBG), tetrahydrocannabinolic acid (THCA), cannabidiolic acid (CBDA), and tetrahydrocannabivarin (THCV) in oily based preparations. The chromatographic separation was carried out using an Hypersil Gold PFP (50 × 2.1 mm, 1.9 µm) column, using H2O + 2 mM ammonium formate + 0.2 % formic acid (M1) and Methanol + 2 mM ammonium formate + 0.2 % formic acid (M2) as mobile phases. The flow rate was set 0.4 mL/min. Specifically, this method was validated in terms of linearity, limit of detections and quantifications (LODs and LOQs), accuracy (precision and trueness, both intra and interday), selectivity, and matrix effects. This procedure allowed quantifying seven phytocannabinoids in less than 10 min. The validated method shows a good linearity within the range 0.25-1000 ng/mL, while precision and trueness (intra- and inter-day) were below <13.25 % and 7.59 %, respectively. Regarding the matrix effect, the method satisfies all the requirements, except for the THC and THCV, where it reaches about 120 %. This element does not affect the method performances as it has been observed that this value is constant and reproducible and therefore does not involve errors in the quantitative analysis. The method was tested and applied on more 70 different oily based preparations. Furthermore, starting from four different cannabis cultivar (FM2, Bedrolite, Bedrocan, and Bediol), it allowed to evaluate the reproducibility of the magistrali preparations. The real samples, in fact, derive from different local pharmacies, and were analyzed by the accredited UNI CEI EN ISO/IEC 17025:2018, Pharmatoxicology Laboratory (ACCREDIA, lab n. 2274 ASLPE, accreditation number 1822 L), accordingly to the current regulations.

Square-wave anodic-stripping voltammetric determination of Cd, Pb, and Cu in a hydrofluoric acid solution of siliceous spicules of marine sponges (from the Ligurian Sea, Italy, and the Ross Sea, Antarctica).

Square-wave anodic-stripping voltammetry (SWASV) was set up and optimized for simultaneous determination of cadmium, lead, and copper in siliceous spicules of marine sponges, directly in the hydrofluoric acid solution (approximately 0.55 mol L(-1) HF, pH approximately 1.9). A thin mercury-film electrode (TMFE) plated on to an HF-resistant epoxy-impregnated graphite rotating-disc support was used. The optimum experimental conditions, evaluated also in terms of the signal-to-noise ratio, were as follows: deposition potential -1100 mV vs. Ag/AgCl, KCl 3 mol L(-1), deposition time 3-10 min, electrode rotation 3000 rpm, SW scan from -1100 mV to +100 mV, SW pulse amplitude 25 mV, frequency 100 Hz, DeltaE(step) 8 mV, t(step) 100 ms, t(wait) 60 ms, t(delay) 2 ms, t(meas) 3 ms. Under these conditions the metal peak potentials were Cd -654 +/- 1 mV, Pb -458 +/- 1 mV, Cu -198 +/- 1 mV. The electrochemical behaviour was reversible for Pb, quasi-reversible for Cd, and kinetically controlled (possibly following chemical reaction) for Cu. The linearity of the response with concentration was verified up to approximately 4 microg L(-1) for Cd and Pb and approximately 20 microg L(-1) for Cu. The detection limits were 5.8 ng L(-1), 3.6 ng L(-1), and 4.3 ng L(-1) for Cd, Pb, and Cu, respectively, with t(d) = 5 min. The method was applied for determination of the metals in spicules of two specimens of marine sponges (Demosponges) from the Portofino natural reserve (Ligurian Sea, Italy, Petrosia ficiformis) and Terra Nova Bay (Ross Sea, Antarctica, Sphaerotylus antarcticus). The metal contents varied from tens of ng g(-1) to approximately 1 microg g(-1), depending on the metal considered and with significant differences between the two sponge species.

Biofilm formation by Haemophilus influenzae isolated from adeno-tonsil tissue samples, and its role in recurrent adenotonsillitis.

Aim of the present study was to identify bacterial biofilms in tissue samples obtained from paediatric patients undergoing surgical treatment, for chronic and recurrent adeno-tonsillitis, not responding to repeated cycles of selective medical antibiotic and anti-inflammatory treatment and to assay the ability of Haemophilus influenzae strains, most frequently identified in the culture examinations, to grow as biofilm in vitro. Overall, 25 surgical specimens (15 adenoids, 10 tonsils) were examined from the upper respiratory tract, from 15 paediatric patients (mean age 6 years). All patients were affected by recurrent and/or chronic adenoiditis and adenotonsillitis unresponsive to selective antibiotic and anti-inflammatory therapy. Tissues were cultured using conventional methods and subjected to scanning electron microscopy for detection of biofilm. Haemophilus influenzae strains, were cultured on 96-sterile well polystyrene microtitre plates (CELLSTAR-greiner bio-one) and stained with 1% crystal violet to quantify biofilm production. Bacterial cocci attached to the tissue surface and organized in colonies, with a morphology consistent with bacterial coccoid biofilms, were observed in all adenoid (15/15) and in 6/10 tonsil samples. Haemophilus influenzae isolates from 12/25 (48%) of our tissue samples scored a percent transmittance (%T(bloc)) > 50, displaying a high capacity to form biofilms (level 4). In conclusion identification of bacterial biofilms in chronic and/or recurrent paediatric upper airway inflammatory processes and the capacity to produce biofilm in vitro, demonstrated by Haemophilus influenzae (the most frequently identified bacteria in our samples), could be related to the aetiopathogenic role of biofilms in chronic inflammatory mucosal reactions and to the resistance of these infections to selective antibiotic therapy.

Determination of water-soluble and insoluble (dilute-HCl-extractable) fractions of Cd, Pb and Cu in Antarctic aerosol by square wave anodic stripping voltammetry: distribution and summer seasonal evolution at Terra Nova Bay (Victoria Land).

Eight PM10 aerosol samples were collected in the vicinity of the "Mario Zucchelli" Italian Antarctic Station (formerly Terra Nova Bay Station) during the 2000-2001 austral summer using a high-volume sampler and precleaned cellulose filters. The aerosol mass was determined by differential weighing of filters carried out in a clean chemistry laboratory under controlled temperature and humidity. A two-step sequential extraction procedure was used to separate the water-soluble and the insoluble (dilute-HCl-extractable) fractions. Cd, Pb and Cu were determined in the two fractions using an ultrasensitive square wave anodic stripping voltammetric (SWASV) procedure set up for and applied to aerosol samples for the first time. Total extractable metals showed maxima at midsummer for Cd and Pb and a less clear trend for Cu. In particular, particulate metal concentrations ranged as follows: Cd 0.84-9.2 microg g(-1) (average 4.7 microg g(-1)), Pb 13.2-81 microg g(-1) (average 33 microg g(-1)), Cu 126-628 microg g(-1) (average 378 microg g(-1)). In terms of atmospheric concentration, the values were: Cd 0.55-6.3 pg m(-3) (average 3.4 pg m(-3)), Pb 8.7-48 pg m(-3) (average 24 pg m(-3)), Cu 75-365 pg m(-3) (average 266 pg m(-3)). At the beginning of the season the three metals appear widely distributed in the insoluble (HCl-extractable) fraction (higher proportions for Cd and Pb, 90-100%, and lower for Cu, 70-90%) with maxima in the second half of December. The soluble fraction then increases, and at the end of the season Cd and Pb are approximately equidistributed between the two fractions, while for Cu the soluble fraction reaches its maximum level of 36%. Practically negligible contributions are estimated for crustal and sea-spray sources. Low but significant volcanic contributions are estimated for Cd and Pb (approximately 10% and approximately 5%, respectively), while there is an evident although not quantified marine biogenic source, at least for Cd. The estimated natural contributions (possibly including the marine biogenic source) cannot account for the high fractions of the metal contents, particularly for Pb and Cu, and this suggests that pollution from long-range transport is the dominant source.