Fully Automated Determination of Four Androgenic Hormones in Serum by Online Turbulent Flow Solid Phase Extraction Coupled with Liquid Chromatography-Tandem Mass Spectrometry / 分析化学

A novel method was developed for the direct analysis of testosterone, androstenedione, methyltestosterone and methenolone in serum samples by fully automated online turbulent flow solid phase extraction coupled with high performance liquid chromatography-tandem mass spectrometry. An aliquot of 50 μL serum sample was preconcentrated directly on a Turboflow SPE column after centrifugation. Turboflow SPE C18-P could be used to remove serum matrix effectively. The optimum loading flow rate and elution time were 4. 0 mL/min and 1. 0 min, respectively. The linearity ranges were from 1. 0 μg/L to 100. 0 μg/L for four target compounds. The method limits of detection ( LODs) were in the range of 0. 2-0. 3 μg/L. The relative standard deviations (RSDs) ranged from 2. 9% to 14. 1% (n=5). The time for one sample analysis including extraction, separation and determination was 32 min. The proposed method has been successfully applied for the analysis of serum samples.

Inhibition of polymerase activity by pristine fullerene nanoparticles can be mitigated by abundant proteins.

Pristine fullerene nanoparticles are capable of adsorbing polymerase and significantly inhibiting its biologically important replication activity; however, the inhibition can be partially mitigated by abundant proteins through competitive binding.

Chemometrics methods for the investigation of methylmercury and total mercury contamination in mollusks samples collected from coastal sites along the Chinese Bohai Sea.

The development and application of chemometrics methods, principal component analysis (PCA), cluster analysis and correlation analysis for the determination of methylmercury (MeHg) and total mecury (HgT) in gastropod and bivalve species collected from eight coastal sites along the Chinese Bohai Sea are described. HgT is directly determined by atomic fluorescence spectrometry (AFS), while MeHg is measured by a laboratory established high performance liquid chromatography-atomic fluorescence spectrometry system (HPLC-AFS). One-way ANOVA and cluster analysis indicated that the bioaccumulation of Rap to accumulate Hg was significantly (P<0.05) different from other mollusks. Correlation analysis shows that there is linear relationship between MeHg and HgT in mollusks samples collected from coastal sites along the Chinese Bohai Sea, while in mollusks samples collected from Hongqiao market in Beijing City, there is not any linear relationship.

Preparation of polyaniline coating on a stainless-steel wire using electroplating and its application to the determination of six aromatic amines using headspace solid-phase microextraction.

A novel polyaniline (PANI) coating was prepared on a stainless-steel wire for solid-phase microextraction by electroplating method. For better mechanical strength, the stainless-steel wire was used instead of the fused silica fiber. The electroplating method had advantages of ease of preparation and simple equipments. The PANI fiber was evaluated by analyzing six aromatic amines (aniline, N,N-dimethylaniline, m-methylaniline, 2,4-dimethylaniline, 2-chloroaniline, 3,4-dichloroaniline) in water. After the analytical procedure was optimized, the linearity was from 4.8 to 2.75 x 10(4) microg L(-1) and the detection limits was from 0.019 to 1.06 microg L(-1). Relative standard deviations were found to be 2.02-6.00%. Good recoveries were obtained when wastewater samples were analyzed.

Determination of Butyltin Compounds in Sediments by Headspace Solid Phase Microextraction and Capillary Gas Chromatography with Flame Photometric Detector Using Quartz Surface-Induced Luminescence / 分析化学

Solid phase microextraction(SPME) can be effectively used to extract volatile and semivoltaile organic compounds from different environmental matrix. In this paper, we utilize headspace-SPME technique combined with capillary gas chromatography (CGC) and a laboratory modified flame photometric detector using quartz surfaceinduced luminescence (QSIL-FPD) for analyzing butyltin compounds in sediments. The detection limits of mono-,di-, and tri-butyltin compounds, based on the signal equal to 3 times the baseline noise are 16.9 ng/g, 1.58 ng/g adn 0.17 ng/g, respectively.

Determination of Inorganic Mercury and Total Organomercury in ChemicalWaste Water by Cold Vapor Generation-Atomic Fluorescence Spectrometry / 分析化学

A sensitive method for the determination of inorganic mercury and total organomercury in chemical waste water by cold vapor generation-atomic fluorescence spectrometry (CVG-AFS) was proposed. Inorganic mercury was directly determined by CVG-AFS. Organomercury was oxidized by potassium persulfate to its inorganic form prior to analysis. The difference between the two data was the value of total organomercury. Parameters affecting the sensitity in the process for the determination of mercury had been studied and optimized. Detection limit of mercury chloride was 8.2 ng/L.

Qualitative Determination of Organotin Species in Lard byGas Chromatography with Flame Photometric Detector andGas Chromatography／Mass Spectrometry / 分析化学

The organotin compounds in the contaminated lard samples were identified by gas chromatography-flame photometric detector and gas chromatography/mass spectrometry after propylation with Grignard reagent. Experimental results identified that all lard samples contain dimethyltin compound and most of these samples contain tri-and monomethyltin compounds.