Chemical Analysis

The Factor IX gene coding for the coagulation factor IX and its deficiency causes Hemophilia B, or Christmas disease. It is an X-linked recessive disorder that affects 1:25000 male births. In the last few years the searches for mutations and sequence polymorphisms have been dramatically changed by the use of PCR and subsequently by direct sequencing of PCR products. In addition a number of prescreening methods have been developed such as single strand conformation polymorphism (SSCP). SSCP is the simplest and most used method of mutation detection. In this study we evaluated the sensitivity of SSCP in finding Factor IX gene mutations. We used peripheral blood from Iranian Hemophilia B patients. DNA were extracted by Phenol Chloroform and other methods. All coding and regulatory regions of the gene were amplified by 11 pairs of primers. SSCP was done by a modified Orita et al. method. The PCR fragments with altered mobility were sequenced. We found deletion, insertion, missense and n...

Micromachining technology was used to prepare chemical analysis systems on glass chips (1 centimeter by 2 centimeters or larger) that utilize electroosmotic pumping to drive fluid flow and electrophoretic separation to distinguish sample components. Capillaries 1 to 10 centimeters long etched in the glass (cross section, 10 micrometers by 30 micrometers) allow for capillary electrophoresis-based separations of amino acids with up to 75,000 theoretical plates in about 15 seconds, and separations of about 600 plates can be effected within 4 seconds. Sample treatment steps within a manifold of intersecting capillaries were demonstrated for a simple sample dilution process. Manipulation of the applied voltages controlled the directions of fluid flow within the manifold. The principles demonstrated in this study can be used to develop a miniaturized system for sample handling and separation with no moving parts.

G-protein-dependent receptor kinases (GRKs) play a key role in the adaptation of receptors to persistent stimuli. In rod photoreceptors rhodopsin kinase (RK) mediates rapid desensitization of rod photoreceptors to light by catalyzing phosphorylation of the visual pigment rhodopsin. To study the structure and mechanism of GRKs in human photoreceptors, we have isolated and characterized cDNA and genomic clones derived from the human RK locus using a bovine rhodopsin kinase cDNA fragment as a probe. The RK locus, assigned to chromosome 13 band q34, is composed of seven exons that encode a protein 92% identical in amino acid sequence to bovine rhodopsin kinase. The marked difference between the structure of this gene and that of another recently cloned human GRK gene suggests the existence of a wide evolutionary gap between members of the GRK gene family.

There has been a significant increase of interest in polar compound separation by hydrophilic interaction liquid chromatography (HILIC), in which acetonitrile is mostly used as a weak eluent. Although replacing acetonitrile with alcohols as organic modifiers has been previously reported, the separation mechanism was poorly understood. In this paper we explored the separation mechanism through the method development for the analysis of the trace amounts of polar and basic hydrazines, which were genotoxic in nature. Separation parameters such as the type and concentration of alcohol, acid modifier, and buffer in mobile phase as well as the choice of stationary phase and column temperature were studied. The data indicated that both electrostatic and hydrophilic interactions contributed to the retention and separation of the hydrazines. The results presented here provide insight into the adjustment of the retention and separation of analytes in HILIC mode with alcohol as a weak eluent. The optimized HILIC method coupled with chemiluminescent nitrogen detection (CLND) is simple and sensitive (reporting limit at 0.02%) and was applied to simultaneous analysis of hydrazine and 1,1-dimethylhydrazine in a pharmaceutical intermediate.

This paper describes development, optimization and validation of a method for the simultaneous determination of 29 multi-class pharmaceuticals using off line solid phase extraction (SPE) followed by liquid chromatography-triple quadrupole mass spectrometry (LC-MS-MS). Target compounds include analgesics and non-steroidal anti-inflammatories (NSAIDs), lipid regulators, psychiatric drugs, anti-histaminics, anti-ulcer agent, antibiotics and beta-blockers. Recoveries obtained were generally higher than 60% for both surface and wastewaters, with exception of several compounds that yielded lower, but still acceptable recoveries: ranitidine (50%), sotalol (50%), famotidine (50%) and mevastatin (34%). The overall variability of the method was below 15%, for all compounds and all tested matrices. Method detection limits (MDL) varied between 1 and 30ng/L and from 3 to 160ng/L for surface and wastewaters, respectively. The precision of the method, calculated as relative standard deviation (R.S...

Essential oils from oregano (Origanum vulgare), thyme (Thymus vulgaris) and cinnamom (Cinnamomum zeylanicum) were tested for their inhibitory activity against sixty Salmonella sp. isolates. These microorganisms were distributed in 20 serovars, all of them isolated from broiler chickens. Based on microdilution technique, the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were determined. The strongest antibacterial activity was obtained for oregano (MIC mean = 529mg ml-1 and MBCmean = 661mg ml-1), followed by a moderate activity for thyme (MICmean=961mg ml-1 and MBCmean=1074mg ml-1) and the lowest obtained activity observed for cinnamon (MICmean= 1335mg ml-1 and MBCmean= 1979mg ml-1). Despite of this activity pattern, the serovars of Salmonella enterica showed significant susceptibility variations. However none of them could be classified as sensitive or resistant to the three essential oils tested. At the moment, when the antibiotics, as growth promoters, are being replaced, the essential oils from spices could be a very reasonable choice and the present results show us two points: the essential oils from oregano and thyme are effective against Salmonella isolates but the variations among the serovars must be considered.

Thermochemical processing of biomass produces a solid product containing char (mostly carbon) and ash. This char can be combusted for heat and power, gasified, activated for adsorption applications, or applied to soils as a soil amendment and carbon sequestration agent. The most advantageous use of a given char depends on its physical and chemical characteristics, although the relationship of char properties to these applications is not well understood. Chars from fast pyrolysis and gasification of switchgrass and corn stover were characterized by proximate analysis, CHNS elemental analysis, Brunauer-Emmet-Teller (BET) surface area, particle density, higher heating value (HHV), scanning electron microscopy, X-ray fluorescence ash content analysis, Fourier transform infrared spectroscopy using a photo-acoustic detector (FTIR-PAS), and quantitative 13C nuclear magnetic resonance spectroscopy (NMR) using direct polarization and magic angle spinning. Chars from the same feedstocks produced under slow pyrolysis conditions, and a commercial hardwood charcoal, were also characterized. Switchgrass and corn stover chars were found to have high ash content (32–55 wt %), much of which was silica. BET surface areas were low (7–50 m2/g) and HHVs ranged from 13 to 21 kJ/kg. The aromaticities from NMR, ranging between 81 and 94%, appeared to increase with reaction time. A pronounced decrease in aromatic CH functionality between slow pyrolysis and gasification chars was observed in NMR and FTIR-PAS spectra. NMR estimates of fused aromatic ring cluster size showed fast and slow pyrolysis chars to be similar (∼7–8 rings per cluster), while higher-temperature gasification char was much more condensed (∼17 rings per cluster). © 2009 American Institute of Chemical Engineers Environ Prog, 2009