Elemental analysis of hourly collected air filters with X-ray fluorescence under grazing incidence.

The X-ray fluorescence under grazing incidence condition (XRF-UGI) was applied for the direct analysis of aerosol filters. Particulate matter less than 2.5 microns (PM2.5) was collected hourly on polytetrafluoroethylene filters using a continuous PM monitor with a virtual impactor method. Although the sampling mass is in trace amounts of 5-30 µg, the metallic contents, such as V, Cr, Mn, Fe, Zn, and Pb, can be measured at sub-ng m-3 detection limits. The effects of the non-uniformity and poor flatness of the PM filters were discussed with regard to the measurement repeatability. The relationship between the XRF-UGI intensities and the mass concentrations obtained via conventional X-ray fluorescence (XRF) analysis was confirmed using the fundamental parameter method. Finally, quantification was successfully demonstrated using the XRF-UGI results with the relative sensitivity factors.

Total Quantification of Magnesium Alloys by X-ray Fluorescence Spectrometry Using the "Standardless" Fundamental Parameter Method.

X-ray fluorescence spectrometry using the "standardless" fundamental parameter method has been studied for the whole elemental analysis of magnesium alloys. Twelve major elements were determined: Mg, Al, Si, Ca, Mn, Fe, Ni, Cu, Zn, Ag, Sn and Pb. The specimens used were over 30 mm in diameter and greater than 10 mm thick to determine Sn Kα which has the largest analyzing depth (9 mm) through the alloy samples. The surfaces of the specimens were polished with fine alumina abrasive paper (#240) to remove the oxide layer and to avoid the influence of any surface roughness variation on the intensities of Mg Kα, Al Kα and Si Kα which have smaller analyzing depths. The total quantitative values of the 12 elements, determined by the FP calculation, were normalized to 100 mass%. The analytical values obtained by this method were comparable to those obtained by the conventional calibration curves method. The relative standard deviations were 6.6% for 0.0014 mass% of Ni, and 0.005% for 93.82 mass% of Mg in AZ91 series Mg alloys. The validation results of the proposed method for 12 elements were successful for the five CRMs tested.

Comparison of Properties among Dendritic and Hyperbranched Poly(ether ether ketone)s and Linear Poly(ether ketone)s.

Poly(ether ether ketone) dendrimers and hyperbranched polymers were prepared from 3,5-dimethoxy-4'-(4-fluorobenzoyl)diphenyl ether and 3,5-dihydroxy-4'-(4-fluorobenzoyl)diphenyl ether through aromatic nucleophilic substitution reactions. 1-(tert-Butyldimethylsiloxy)-3,5-bis(4-fluorobenzoyl)benzene was polycondensed with bisphenols, followed by cleavage of the protective group to form linear poly(ether ketone)s having the same hydroxyl groups in the side chains as the chain ends of the dendrimer and hyperbranched polymers. Their properties, such as solubilities, reduced viscosities, and thermal properties, were compared with one another. Similar comparisons were also carried out among the corresponding methoxy group polymers, and the size of the molecules was shown to affect the properties.

Simultaneous determination of nicotine and cotinine in serum using high-performance liquid chromatography with fluorometric detection and postcolumn UV-photoirradiation system.

A simple and rapid method for the simultaneous determination of serum nicotine and cotinine using high-performance liquid chromatography (HPLC)-fluorometric detection with a postcolumn ultraviolet-photoirradiation system was developed. Analytes were extracted from alkalinized human serum via liquid-liquid extraction using chloroform. The organic phase was back-extracted with the acidified aqueous phase, and the analytes were directly injected into an ion-pair reversed-phase HPLC system. 6-Aminoquinoline was used as an internal standard. Nicotine, cotinine, and 6-aminoquinoline were separated within 14min. The extraction efficiency of nicotine and cotinine was greater than 91%. The linear range was 0.30-1000ng for nicotine and 0.06-1000ng for cotinine. In serum samples from smokers, the concentrations of nicotine and cotinine were 8-15ng/mL and 156-372ng/mL, respectively.

Enantioseparation of nicotine alkaloids in cigarettes by CE using sulfated beta-CD as a chiral selector and a capillary coated with amino groups.

Nicotine (NC) and its related compounds (cotinine (CN), nornicotine (NN), anatabine (AT) and anabasine (AB)) were simultaneously enantioseparated by CE using a capillary with amino groups and sulfated beta-CD as a chiral selector. The optimum running conditions were found to be 30 mM acetate buffer (pH 5.0) containing 8% sulfated beta-CD with an applied voltage of +15 kV at 30 degrees C using direct detection at 260 nm. Using a capillary coated with amino groups, the EOF migrates toward the positive pole. However, when sulfated beta-CD was added to the BGE, it was found that the EOF migrated toward the negative pole due to ionic adsorption of sulfated beta-CD to amino groups on the capillary inner wall. All the cationic analytes migrated as anions, suggesting that they formed stable anionic complexes with sulfated beta-CD. With this system and a simple pretreatment with mini-cartridges, NC alkaloids in five cigarette samples were enantioseparated. As a result, each of the compounds except for CN was detected. In the case of NC, only (S)-NC was detected (more than 99.9%), but in the case of NN, AT and AB, the ratios of (S)-isomer to total isomers were in the ranges 58-70, 81-85 and 59-65%, respectively. On the other hand, only NC was detected in cigarette smoke and the ratio of (S)- and (R)-NCs was 96:4. The amounts of NC alkaloids in cigarettes suggest that the production of (R)-NC resulted from racemization due to the high temperature/burning of the cigarette.