Veniero Gambaro

Validation of a GC/MS method for the determination of tramadol in human plasma after intravenous bolus ☆

Tramadol quantitative determination by gas chromatography-mass spectrometry (GC/MS) using nefopam hydrochloride as internal standard (IS) and two calibration curves because of the large range of concentration attended in the plasmatic samples is described. Plasma samples drawn from subjects in postoperative period treated with two different initial intravenous (iv) bolus of tramadol (50 and 100 mg) followed by tramadol at the same infusion rate (12 mg h(-1)) are analysed. We operated for the qualitative analysis in Scan mode while for the quantitative analysis in SIM mode, selecting the ion m/z 58 for tramadol and m/z 179 for IS. The limit of detection (LOD) was 0.01 microg ml(-1) and the limit of quantification was 0.04 microg ml(-1).

Cigarette smoke negatively and dose-dependently affects the biosynthetic pathway of the n-3 polyunsaturated fatty acid series in human mammary epithelial cells

Maternal smoking during pregnancy has been associated with a reduced content of n−3 long-chain PUFA (LC-PUFA) in breast milk, thereby reducing the intake of key nutrients by the infants. We postulated that the mammary gland is affected by maternal smoking in the process of n−3 LC-PUFA secretion into milk. This prompted us to investigate the effects of cigarette smoke on the synthesis of n−3 LC-PUFA in vitro by using a line of healthy epithelial cells from the human mammary gland, MCF-10A. Cells were exposed to cigarette smoke under controlled conditions by adding to the medium aliquots of horse serum containing smoke components, as analyzed by GC-MS. The major findings concern the inhibition of both the conversion of the precursor 14C-ALA (α-linolenic acid) to n−3 LC-PUFA and of the Δ5 desaturation step (assessed by HPLC analysis with radiodetection of n−3 FAME) following exposure to minimal doses of smoke-enriched serum, and the dose-dependent relationship of these effects. The data indicate that exposure to cigarette smoke negatively affects the synthesis of n−3 LC-PUFA from the precursor in mammary gland cells.

Determination of primary active constituents in Cannabis preparations by high-resolution gas chromatography/flame ionization detection and high-performance liquid chromatography/UV detection

Abstract For a complete quantitative analysis of primary active constituents in Cannabis preparations Δ 9 -tetrahydrocannabinol (THC), cannabidiol (CBD) and cannabinol (CBN), we have compared two different chromatographic techniques, high-resolution gas chromatography (HRGC)/flame ionization detection (FID) and high-performance liquid chromatography (HPLC)/UV. The two different methods have been validated using crude drug (hashish) with methyloleate and tetraphenylethylene as internal standard for HRGC/FID and HPLC/UV, respectively.

Determination of the active principles of Catha Edulis: Quali–quantitative analysis of cathinone, cathine, and phenylpropanolamine

In the last years, all the vegetable material supposed to belong to the Catha Edulis species, seized at the Malpensa and Orio al Serio airports, were analyzed in our laboratory on behalf of the Tribunals of Busto Arsizio and Bergamo, respectively. After a preliminary botanic examination, the quali-quantitative determination of the active principles cathinone, cathine and phenylpropanolamine (PPA) was carried out by means of GC/MS and GC/FID techniques, which meet the requirements of the forensic analyses. We developed a fast, effective and reliable derivatization procedure which allowed to simultaneously detect cathine and PPA, whose discrimination is mandatory since PPA is not a psychoactive agent. Cathine was distributed in the various parts of the plant (leaves and stems) and its quantity ranged from 0.03% to 0.17% of the weight of the vegetable material; PPA was not detected in the twigs and its quantity in the leaves ranged from 0.07% to 0.16%. The quantitative determination of cathinone was carried out directly on the methanol solution after maceration of the vegetable material, its quantity ranging from 0.02% to 0.10%. No significant difference in the content of the two active principles was found between the fresh and the dried material.

Characterization of in vitro metabolites of JWH-018, JWH-073 and their 4-methyl derivatives, markers of the abuse of these synthetic cannabinoids.

In vitro incubation with human liver microsomes of JWH-018, JWH-073, JWH-122 and for the first time 1-butyl-3-(1-(4-methyl)naphthoyl)indole (the 4-methylnaphthoyl analogue of JWH-073) was investigated to identify the principal metabolites of alkylindole synthetic cannabinoids, thus helping the discovering of synthetic cannabinoids abusers. The results obtained showed that the most abundant metabolites were mono-hydroxylated derivatives either on the alkyl chain (ω or ω-1 position) or on the indole (presumably in position 5 or 6) and naphthalene moieties. Moreover the extraction conditions of these derivatives from biological fluids, mainly plasma and urine spiked with commercially available metabolite standards, and the incubation procedure were investigated to obtain a fast, reliable and suitable extraction protocol to detect either the parent drugs or their metabolites by means of GC/MS.

Unexpected Variation of the Codeine/Morphine Ratio Following Fatal Heroin Overdose

Postmortem samples from 14 cases of suspected heroin overdose were subjected to a preliminary systematic toxicological analysis in order to highlight the presence of unknown exogenous compounds (e.g., drugs of abuse, alcohol) that may have played a role in the mechanism of death. This analysis unveiled histories of poly-drug use in seven of the cases under investigation. Moreover, the concentrations of morphine and codeine in the brain were also investigated, and the results were compared with the data obtained from the blood specimens. The concentration of morphine in blood ranged from 33 to 688 ng/mL, while the concentration of codeine ranged from 0 to 193 ng/mL. However, in the brain, the concentration of morphine was found to be between 85 and 396 ng/g, while the levels of codeine ranged from 11 to 160 ng/g. The codeine/morphine ratio in the blood ranged from 0.043 to 0.619; however, in the brain, the same ratio was found to be between 0.129 and 0.552. In most cases, a significantly higher codeine/morphine ratio was found in the brain, suggesting the accumulation of codeine in brain tissue due its high lipophilicity as compared with morphine.

Identification of 1-butyl-3-(1-(4-methyl)naphtoyl)indole detected for the first time in “herbal high” products on the Italian market

The results of the analysis of some herbal products and powders adulterated with alkylindoles recovered on the Italian market between 2010 and 2011 are reported. Besides the well-known alkyindoles JWH-018 and JWH-073, other derivatives such as JWH-250 and AM-694 have been detected and for the first time in Italy 1-butyl-3-(1-(4-methyl)naphthoyl)indole (compound 1), the 4-methylnaphthoyl analogue of JWH-073. This compound as well as the other alkylindoles has been synthesized and characterized by (1)H NMR, (13)C NMR, DSC, GC/MS, and elemental analysis. The quantitative analyses of the samples have been carried out by means of the GC/FID method developed in our laboratory for the analysis of herbal high products containing naphthoylindoles; the quantity of the cannabimimetic substances ranged from 6 mg/g to 47 mg/g.

A case of fatal intoxication from metformin

A case of fatal intoxication from metformin is presented. The decedent was an obese 58‐year‐old‐woman with type II diabetes, in whom severe lactic acidosis secondary to metformin accumulation was precipitated by acute renal failure. She had been on metformin 500 mg twice a day. Postmortem blood was deproteinated with acetonitrile, washed with dichloromethane, and the resulting supernatant injected into high‐performance liquid chromatography system. Separation was performed on a analytical 125 × 4 mm i.d. RP‐8 column. The wavelength was set at 235 nm. The mobile phase was acetonitrile (40%), sodium lauryl sulfate, and sodium dihydrogen phosphate adjusted to pH 5.1 (60%) at a flow rate of 1.0 mL/min. The concentration of metformin in postmortem blood was 77.3 μg/mL. The qualitative result was also confirmed by LC/APCI/MS/MS analysis.

Capillary electrophoretic and extraction conditions for the analysis of Catha edulis FORKS active principles

A capillary electrophoretic method, which allowed the detection and separation of the active principles of Catha edulis, i.e. cathinone, cathine and phenylpropanolamine, was developed. A suitable internal standard (nicotinamide), which permitted the quantification of the analytes reducing the variability of the migration times due to EOF changes, was identified. The analytical method was validated, assessing linearity, sensitivity and repeatability, showing optimal features for the analysis of the vegetable material. Moreover extraction conditions were investigated to achieve the exhaustion of the plant material in the fastest and most efficient way to meet the requirements of the Court.

Improved GC method for the determination of the active principles of Catha edulis

The GC method previously reported by our research group for the analysis of the active principles of Catha edulis, i.e. cathine, cathinone and phenylpropanolamine, was considerably improved. N-methyl-N-trimethylsilyl-trifluoroacetamide (MSTFA) as derivatizing agent was employed, thus allowing an accurate determination of the analytes and a suitable internal standard for quantitative analyses (nicotinamide) was introduced. Moreover the chromatographic conditions were carefully studied to improve the separation of the alkaloids and sensitivity. To this end different chromatographic capillary columns and temperature gradients were investigated. The optimized GC method was validated and resulted adequate for the application in forensic analysis. Finally on behalf of the Tribunal, C. edulis vegetable material seized by the police in northern Italy was analyzed, the quantity of cathine ranging from 0.095 to 0.29%, the quantity of PPA from 0.010 to 0.21% and the quantity of cathinone from 0.025 to 0.374% of the weight of the vegetable material.