GC/MS analysis of the hydrodistilled essential oils and volatiles from the aerial parts of Cannabis sativa L.

Cannabis sativa L. has been recognised as a narcotic drug in different parts of the world. The current report deals with the screening of the chemical profiles of the essential oils (EOs) and volatiles obtained from the aerial ports of Cannabis sativa L. (APCS) using classical hydrodistillation (HD), solid phase microextraction (SPME) along with a new technique namely innovative cigarette ignition (Incigig); all in combination with GC/MS. The characterised profiles had considerable differences from quantitative and qualitative points of view, with a high prevalence of non-terpene hydrocarbons for the EO and oxygenated monoterpenes for both volatiles using SPME and Incigig approaches.

Screening of the compositions of essential oils and volatiles of Perovskia abrotanoides Karel. along with antioxidant, antibacterial and cytotoxic impacts of its methanol extract.

In the present report, a combination of classical and advanced methods, namely classical hydrodistillation (HD) and solvent free microwave extraction (SFME) have been used for the extraction of essential oils from flowers, leaves and stems of Perovskia abrotanoides Karel. as an endemic plant to Golestan Province, Iran. The volatile fractions from the same plant organs have been separated using a solid phase microextraction (SPME) fibre and characterised using a GC/MS apparatus. Moreover, oxygenated monoterpenes, for example, 1,8-cineole and borneol were found as the most constituent components of the majority of the characterised profiles. Accordingly, for flowers, leaves and stems of P. abrotanoides Karel., the relevant quantities were HD: 12.0 and 12.4, 24.0 and 17.9, 12.9 and 16.8%; SFME: 15.6 and 15.2, 20.5 and 16.2, 13.5 and 14.7%; SPME: 20.9 and 5.2, 25.5 and 9.9, 26.4 and 8.5%, respectively. Total phenolic content (TPC: 52.02 mg GAE/g), total flavonoids content (TFC: 98.46 mg QE/g) as well as antioxidant and antibacterial effects of the extract from the aerial parts of this species have been also evaluated. The cytotoxicity of Perovskia abrotanoides Karel. MeOH extract has been tested against HUVECs cell line. Moreover, our study on the in vitro anti-bladder carcinoma demonstrated that the plant extract reduced the viability of malignant bladder cell line, in a dose dependent way.

Multivariate curve resolution-assisted determination of pseudoephedrine and methamphetamine by HPLC-DAD in water samples.

In the present study, a simple strategy based on solid-phase extraction (SPE) with a cation exchange sorbent (Finisterre SCX) followed by fast high-performance liquid chromatography (HPLC) with diode array detection coupled with chemometrics tools has been proposed for the determination of methamphetamine and pseudoephedrine in ground water and river water. At first, the HPLC and SPE conditions were optimized and the analytical performance of the method was determined. In the case of ground water, determination of analytes was successfully performed through univariate calibration curves. For river water sample, multivariate curve resolution and alternating least squares was implemented and the second-order advantage was achieved in samples containing uncalibrated interferences and uncorrected background signals. The calibration curves showed good linearity (r(2) > 0.994).The limits of detection for pseudoephedrine and methamphetamine were 0.06 and 0.08 µg/L and the average recovery values were 104.7 and 102.3% in river water, respectively.

Liquid-phase microextraction based on two immiscible organic solvents followed by gas chromatography with mass spectrometry as an efficient method for the preconcentration and determination of cocaine, ketamine, and lidocaine in human urine samples.

A new type of liquid-phase microextraction based on two immiscible organic solvents was optimized and validated for the quantification of lidocaine, ketamine, and cocaine in human urine samples. A hollow-fiber based microextraction technique followed by gas chromatography coupled with mass spectrometry detection was used to reduce matrix interferences and improve limits of detection. The analytes were extracted from aqueous sample with pH 11.0, into a thin layer of organic solvent (n-dodecane) sustained in the pores of a hollow fiber, and then into a second organic acceptor (acetonitrile) located inside the lumen of the hollow fiber. With the application of optimized values, good linearity was obtained in the range of 1-500 µg/L for lidocaine and ketamine and 2-500 µg/L for cocaine with the determination coefficient values (r(2) ) >0.9943. The preconcentration factors and limits of detection (S/N > 3) were 250-350 and 0.01-0.05 µg/L, respectively. Intra and interassay precision values were <7.3 and 9.3%, respectively. The method was successfully applied for the determination and quantification of target analytes in human urine samples.

Molecularly imprinted-solid phase extraction combined with simultaneous derivatization and dispersive liquid-liquid microextraction for selective extraction and preconcentration of methamphetamine and ecstasy from urine samples followed by gas chromatography.

In this study, a developed technique was reported for extraction and pre-concentration of methamphetamine (MAMP) and 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) from urine samples using molecularly imprinted-solid phase extraction (MISPE) along with simultaneous derivatization and dispersive liquid-liquid microextraction (DLLME). Molecularly imprinted microspheres as sorbent in solid phase extraction (SPE) procedure were synthesized using precipitation polymerization with MAMP as the template. Aqueous solution of the target analytes was passed through MAMP-MIP cartridge and the adsorbed analytes were then eluted with methanol. The collected eluate was mixed with butylchloroformate which served as the derivatization reagent as well as the extraction solvent. The mixture was immediately injected into deionized water. After centrifugation, 1 µL of the settled organic phase was injected into gas chromatography-flame ionization detection (GC-FID) or gas chromatography-mass spectrometry (GC-MS). Various experimental parameters affecting the performance of both of the steps (MISPE and DLLME) were thoroughly investigated. The calibration graphs were linear in the ranges of 10-1500 ng mL(-1) (MAMP) and 50-1500 ng mL(-1) (MDMA), and the detection limits (LODs) were 2 and 18 ng mL(-1), respectively. The relative standard deviations (%RSDs) obtained for six repeated experiments (100 ng mL(-1) of each drug) were 5.1% and 6.8% for MAMP and MDMA, respectively. The relative recoveries obtained for the analytes in human urine samples, spiked with different levels of each drug, were within the range of 80-88%.

Determination of impurities in illicit methamphetamine samples seized in Iran.

In this study fifty samples of crystalline methamphetamine obtained from antinarcotics police of Iran seized during the year 2010 were analyzed. In order to determine the chemical characteristics of these samples, anion test, Gas Chromatography-Mass Spectrometry (GC-MS) and Liquid Chromatography-Mass Spectrometry (LC-MS) were carried out on the samples. All of the samples containing methamphetamine tested positive for chloride anion. The range of methamphetamine hydrochloride content in these samples was 33-95%. One sample out of 50 contained no methamphetamine. The fact that 1,2-dimethyl-3-phenylaziridine was the most frequently found impurity in the analyzed samples, indicates that most of the methamphetamine samples seized in Iran have been synthesized from pseudoephedrine as starting material.

Electrokinetic extraction on artificial liquid membranes of amphetamine-type stimulants from urine samples followed by high performance liquid chromatography analysis.

Electromembrane extraction (EME) coupled with high performance liquid chromatography and ultraviolet detection was developed for determination of amphetamine-type stimulants in human urine samples. Amphetamines migrated from 3 mL of different human urine matrices, through a thin layer of 2-nitrophenyl octyl ether (NPOE) containing 15% tris-(2-ethylhexyl) phosphate (TEHP) immobilized in the pores of a porous hollow fiber, and into a 15 µL acidic aqueous acceptor solution present inside the lumen of the fiber. Equilibrium extraction conditions were obtained after 7 min of operation. Experimental design and response surface methodology (RSM) were used for optimization of EME parameters. Under optimal conditions, amphetamines were effectively extracted with recoveries in the range of 54-70%, which corresponded to preconcentration factors in the range of 108-140. The calibration curves were investigated in the range of 0-7 µg mL(-1) and good linearity was achieved with a coefficient of estimation better than 0.991. Detection limits and inter-day precision (n=3) were less than 0.01 µg mL(-1) and 11.2%, respectively.

Analysis of abuse drugs in urine using surfactant-assisted dispersive liquid-liquid microextraction.

The process of surfactant-assisted dispersive liquid-liquid microextraction (SA-DLLME) followed by high-performance liquid chromatography-UV detection was successfully applied for the extraction and determination of selected cannabinoids (cannabidiol, Δ(9)-tetrahydrocannabinol, and cannabinol) in urine samples. The effective parameters on the extraction efficiency were studied and optimized utilizing two different optimization methods: one variable at a time (OVAT) and face center design (FCD). Under the optimum conditions (extraction solvent and its volume, toluene, 85 µL; disperser agent and its concentration, 1.0 mL of ultra-pure water containing 0.5 mmol/L tetradecyl tremethyl ammonium bromide (TTAB); sample pH, 2.0 and salt concentration, 11% w/v NaCl), the limits of detection of the method were in the range of 0.1-0.5 µg/L and the repeatability and reproducibility of the proposed method, expressed as relative deviation, varied between 4.1 and 8.5% and 6.7 and 11.6%, respectively. Linearity was found to be in the range of 1.0-200 µg/L and under the optimum conditions, the preconcentration factors (PFs) were between 190 and 292. This proposed method was successfully applied in the analysis of three male advocate urine samples and good recoveries were obtained.

Investigation of pencil leads fiber efficiency for SPME of trace amount of methamphetamine from human saliva prior to GC-MS analysis.

The efficiency of pencil lead fiber was investigated for effective head-space solid-phase microextraction (HS-SPME) of methamphetamine (MAMP) from aqueous standard solutions without chemical derivatization prior to gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) analyses. Most effective experimental parameters such as extraction temperature and time, sample pH, and salting out were studied and optimized. At the optimum conditions, the efficiency of this fiber was compared with polyacrylate (PA) commercial fiber, which is most selective for volatile and semi-volatile compounds. The results obtained prove the suitability of modified pencil-lead fiber for sampling of the studied compound from aqueous solutions. Under optimum conditions, the calibration plot was linear in the range of 40-8000 ng/mL (r = 0.998), and the detection limit was 27 ng/mL (n = 3). The proposed method was successfully applied for HS-SPME of MAMP from 200 microL human saliva, which has been spiked with trace amounts of MAMP (160 ng/mL) followed by GC-MS monitoring.

SPME and GC-MS analysis of triethylene glycol dimethacrylate released from dental composite.

A solid-phase microextraction (SPME) coupled with gas chromatography followed by mass spectrometry was developed for the determination of triethylene glycol dimethacrylate (TEGDMA) in aqueous media originated from cured dental composite. Cylindrical specimens of a common dental composite were cured and immersed for 48 h in 3 mL portions of human saliva and also some non-biologic media e.g., pure water and Ringer's solution. The extraction was carried out by direct SPME for 15 min. The efficiency and reliability of some commercially available and modified pencil lead fibers were evaluated for the extraction of interest compound from aqueous media. Some effective and experimental parameters of SPME and gas chromatography procedures were examined and optimized. The obtained results reveal that the direct SPME using the modified pencil lead is very effective and can extract TEGDMA with a good selectivety from among various compounds such as 2,6-di-tert-butyl-4-methyl phenol (buylated hydroxy toluene) (BHT), 2-propenoic acid, 2-methyl-oxybis (2,1-ethanediyl oxy-2,1-ethanediyl) ester (TEEGDMA), 3,5-di-t-butyl-4-hydroxy benzaldehyde, benzoic acid 4 (dimethyl-amino)-ethyl ester (DMA BEE), 2-propenoic acid, 2-methyl-dodecyl ester (methacrylic acid, dodecyl ester), 2-ethoxy ethyl methacrylate, and drometrizole (TINP). The results obtained also prove that the studied composite releases 11.0, 13.4, and 28.3 microg/mL TEGDMA into distilled water, Ringer's solution, and saliva, respectively, at 48 h of the exposition.

Forensic discrimination of blue ballpoint pen inks based on thin layer chromatography and image analysis.

This article aims to provide a new and fast method for differentiation of inks on a questioned document. The data acquisition was carried out by designing specific image analysis software for evaluating thin layer chromatograms (TLC-IA). The ink spot was extracted from the document using methanol and separated by TLC using plastic sheet silica gel 60 without fluorescent indicator, and a mixture of ethyl acetate, ethanol, and water (70:35:30, v/v/v) as mobile phase. To discriminate between different pen inks, new software was designed on the basis of intensity profile of red, green, and blue (RGB) characteristic. In practice, after development of chromatogram, the chromatograms were scanned by ordinary office scanner, intensity profiles of RGB characteristics on the development straight of each sample were produced and compared with the mentioned software. RGB profiles of ballpoint inks from various manufacturers showed that the patterns in most cases were distinctly different from each other. This new method allowed discriminating among different pen inks with a high reliability and the discriminating power of 92.8%. Blue ballpoint pen inks of 41 different samples available on the local market were successfully analyzed and discriminated.

Preparation and evaluation of solid-phase microextraction fibers based on monolithic molecularly imprinted polymers for selective extraction of diacetylmorphine and analogous compounds.

All of the studies on solid-phase microextraction based on molecularly imprinted polymers up to now have been carried out on the synthesis of the polymer on the surface of the fiber which is brittle and the polymer coating strips during handling. The objective of this study was to develop a method for fabrication of a monolithic and robust solid-phase microextraction fiber on the basis of molecularly imprinted polymer for selective extraction of diacetylmorphine and its structural analogues followed by their GC or GC/MS analysis. A fiber was produced by copolymerization of methacrylic acid-ethylene glycol dimethacrylate imprinted with diacetylmorphine. The effective factors influencing the polymerization have been investigated and are detailed here. Also, the influences of pH, extraction time and temperature on the extraction efficiency of analytes were investigated. The prepared fiber was thermally stable up to 300 degrees C which has vital importance in SPME coupled with GC or GC/MS. The adsorption isotherm modeling was performed by fitting the data of studied compounds to bi-Langmuir isotherm model. The evaluated equilibrium constants for diacetylmorphine were 0.011 and 1824.72 microM(-1), and the number of binding sites was 170.37 and 4.64 nmolg(-1), respectively. This fiber was successfully used for extraction of template molecule from aqueous solution and further analysis with GC or GC/MS. The high extraction efficiency was obtained for diacetylmorphine, 6-monoacetylcodeine, and 6-monoacetylmorphine, yielding the detection limits of 300, 47, and 1 ngmL(-1), respectively.