Simultaneous HPLC estimation of Amphetamine and Caffeine abuse drugs in Iraqi human addicts

The main aim of this research is to establish and validate a high performance liquid chromatography (HPLC) process for the separation and estimation of Amphetamine (AM) and Caffeine (CAF) in its illegal formula and in sera of addicts. This method is established on the HPLC separation of the two drugs on the ZORBAX ODS column (250×4.6×5µm particle size). The mobile phase contained 1% ortho-phosphoric acid 85% and 1%of diethyl amine 99%, acetonitrile and methanol ratio was 85:10:5 v/v/v. The flow rate is 1.2 mL.min-1, buffer value pH of 2.5 via isocratic elution also UV detection at 210 nm. The retention times for the two drugs AM and CAF were obtained at 4.425 and 6.456 min, respectively. The calibration curves founded that the linear regression analysis data gave a good linear relationship for the concentration range 1 to 100 µg.mL-1 for AM and CAF. The values achieved for correlation coefficient, slope and intercept were 9999, 8104.2 and 5012 for AM and 0.9999, 9698.5 and 6342.9 for CAF, whereas the LOD and LOQ was 0.51, 1.64 µg.mL-1 for AM and 0.60, 1.32 µg.mL-1 for CAF

Sorption properties of modifiers of piezoquartz resonators based on 3d-elements

Transition metals are complexing substances, that is why being incorporated into the sensor modifiers, they can improve detection discrimination. The method of piezoelectric microweighting was used to study the sorption characteristics of the films based on partially soluble phosphates of 3d-elements (manganese (II), iron (II and III), nickel, copper, zinc, chromium) and coatings bearing partially soluble ferrous salts (hydrated oxide, fluoride, carbonate, sulfide, phosphate). The salts were created immediately prior to analysis, with bee glue as a filming agent. The method of immersion sensors in suspension of the filming agent and partially soluble salt, that was kept homogeneous by ultrasonic bath, was recognized the best way of film formation. Sorption characteristics of the composed coatings of piezoelectric resonator were estimated by the area under sorption kinetic curve and by peak value of sensor oscillation frequency drop during analysis of equilibrium gaseous form received over pure substances (water, phenol, isopropanol, isobutanol, acetous acid, chloroform, benzene, toluene, acetone, ethyl acetate, ammonia, diethyl amine, triethylamine, tert-butylamine, benzylamine). It was possible to determine the identifying variables Aij, minimax values of those allow to detect individual substances in the mixed vapour. Modifier application of piezoelectric resonators of phosphates of different 3d-elements is more efficient than use of different salts of one element. The shortcoming of the proposed modifiers is temporarily stable amine (ammonia) complexation. Those analytes desorption from the films proceeds slowly, it is determined by the bond strength of complexes and takes from 2 to 6 hours. However, array of seven sensors, modified by phosphates of transition metals of group IV, allows to detect oxygen- and nitrogen-based compounds vapours in the mixed vapour as well as to detect ammonia, diethyl amine and triethylamine individually.)

The Influence of a Mesoporous Silica on Ru-Sn Catalyst Activity in the Hydrogenation of Methyl Oleate

The hydrogenation of methyl oleate on a Ru-Sn catalyst deposited on Al-HMS was studied in comparison to that conducted on the same catalyst deposited on a conventional support, i.e. g-Al2O3. The catalyst was prepared by sequential impregnation. The distribution of the acid strength of the prepared catalysts was determined by thermic desorption of diethyl amine in the temperature range from 20 to 600�C. Experiments were carried out on a laboratory echipament using a fixed bed catalytic reactor at a temperature of 275�C, pressure of 100 atm with a methyl oleate volume flow rate (VHSV) of 0.15h-1 and molar ratio hydrogen/ methyl oleate of 10/1. The main compounds identified were saturated and unsaturated fatty alcohols and saturated hydrocarbons. Ru-Sn/ Al-HMS + g-Al2O3 shows a higher conversion to liquid products that the Ru-Sn-Ba / g-Al2O3, probably due to a favorable distribution of the acid strength.

Enzymatic synthesis of unsaturated polyesters: functionalization and reversibility of the aza-Michael addition of pendants

Enzymatic synthesis of unsaturated polyesters and the temperature-dependent reversibility of the aza-Michael addition of diethyl amine pendants.

Crystal structures of two stilbazole derivatives: bis{(E)-4-[4-(diethylamino)styryl]-1-methylpyridin-1-ium} tetraiodidocadmium(II) and (E)-4-[4-(diethylamino)styryl]-1-methylpyridin-1-ium 4-methoxybenzenesulfonate monohydrate

The title molecular salts, (C18H23N2)2[CdI4], (I), and C18H23N2 +·C7H7O4S−·H2O, (II), are stilbazole, or 4-styrylpyridine, derivatives. The cation, (E)-4-[4-(diethylamino)styryl]-1-methylpyridin-1-ium, has a methyl group attached to pyridine ring and a diethyl amine group attached to the benzene ring. The asymmetric unit of salt (I), comprises one cationic molecule and half a CdI4 dianion. The Cd atom is situated on a twofold rotation axis and has a slightly distorted tetrahedral coordination sphere. In (II), the anion consists of a 4-methoxybenzenesulfonate and it crystallizes as a monohydrate. In both salts, the cations adopt an E configuration with respect to the C=C bond and the pyridine and benzene rings are inclined to each other by 10.7 (4)° in (I) and 4.6 (2)° in (II). In the crystals of both salts, the packing is consolidated by offset π–π stacking interactions involving the pyridinium and benzene rings, with centroid–centroid distances of 3.627 (4) Å in (I) and 3.614 (3) Å in (II). In the crystal of (II), a pair of 4-methoxybenzenesulfonate anions are bridged by Owater—H...Osulfonate hydrogen bonds, forming loops with an R 2 4(8) motif. These four-membered units are then linked to the cations by a number of C—H...O hydrogen bonds, forming slabs lying parallel to the ab plane.

Ultrasonic Velocity and Heat Transfer Measurement of Binary Fluid (Diethyl Amine + Tetra Hydro Furan) and Hybrid CuO Nanofluid (CuO + Diethyl Amine + Tetra Hydro Furan)

Diethylamine (DEA)+Tetrahydrofuran (THF) Binary fluids and CuO+Diethylamine+Tetrahydrofuran Hybrid CuO nanofluids of various concentrations are prepared using ultrasonic assisted methods. Ultrasonic velocity, thermal conductivity and viscosity values of binary fluids and hybrid CuO nanofluids are measured at temperatures ranging from 298 K to 318 K. Ultrasonic velocity can be used to calculate several acoustic parameters like Adiabatic compressibility (β), Inter molecular free length (Lf), Acoustical impedance (Z) which is very useful in the study of molecular interactions in the binary base fluids and hybrid CuO nanofluids. From the ultrasonic velocity studies the weak interaction present in the binary base fluids and hybrid nanofluids is confirmed. Our experimental result shows that thermal conductivity and viscosity values increases with the addition of CuO nanoparticle. The Brownian movement of the particle and inter particle forces between the molecules is responsible for the changes in thermal conductivity and viscosity.

Hydrogenation of Naphtalene on Pt-Pd Catalyst

The hydrogenation of naphthalene was conducted on Pt-Pd /g-Al2O3 catalyst. Characterization of the catalyst was carried out by determination of acidity and textural characteristics. The distribution of the acid strength of the prepared catalysts was determined by thermic desorption of diethyl amine and textural characteristics were determined by desorption of liquid nitrogen. Experiments were carried out on 1.5-6h-1 and molar ratio hydrogen/ naphthalene of 10/1. The main compounds identified were tetralin, trans and cis-decalin. The naphthalene conversion was higher and grew up with temperature and pressure. Higher activity of Pt-Pd /g-Al2O3 catalyst is probably due to the appropriate distribution of textural and strength acid.