Role of sulfur dioxide in acute lung injury following limb ischemia/reperfusion in rats.

Sulfur dioxide (SO2) is naturally synthesized by glutamate-oxaloacetate transaminase (GOT) from L-cysteine in mammalian cells. We aim to investigate the role of SO2 in inflammation in acute lung injury (ALI) following limb ischemia/reperfusion (I/R). Male Wistar rats were subjected to limb I/R and were injected with saline, GOT inhibitor hydroxamate (HDX, 0.47 mmol/kg), or the SO2 donor Na2 SO3 /NaHSO3 (0.54 mmol/kg/0.18 mmol/kg). Compared with the sham operation, the plasma SO2 levels were significantly decreased by limb I/R treatment. In addition, SO2 concentration and GOT activity in the lung tissue were also reduced in ALI. The occurrence of ALI following limb I/R can be prevented by Na2 SO3 /NaHSO3 treatment, whereas it can be significantly aggravated by HDX. The plasma IL-1ß, IL-6, and IL-10 levels were consistent with myeloperoxidase activity and inflammation in lung tissue. In conclusion, our data suggest that downregulation of endogenous SO2 production might be involved in pathogenesis of ALI following limb I/R in rats.

On-line separation/preconcentration of V(IV)/V(V) in environmental water samples with CTAB-modified alkyl silica microcolumn and their determination by inductively coupled plasma-optical emission spectrometry.

A simple and selective method of flow injection microcolumn separation/preconcentration on-line coupled with inductively coupled plasma-optical emission spectrometry (ICP-OES) was developed for the speciation of V(V)/(IV). Various factors affecting the separation/preconcentration of V(IV) and V(V) by conical microcolumn packed with cetyltrimethylammonium bromide (CTAB)-modified alkyl silica have been systematically investigated. It is found that V(V) was quantitatively retained by the microcolumn at pH 2.0-7.0, while V(IV) was not retained by the microcolumn at pH 2.0-3.5 but quantitatively retained at pH 5.0-7.0. The two vanadium species adsorbed by the modified adsorbent were quantitatively desorbed by 0.10 mL of 1.0 mol L(-1) HNO(3). Therefore, V(V) and total vanadium could be determined by CTAB-modified alkyl silica packed microcolumn separation/preconcentration and on-line ICP-OES detection after adjusting sample solution to pH 2.5 and 6.0, respectively, and the assay of V(IV) was realized by subtracting V(V) from total V. The detection of limit (LOD) for V(V) was 0.03 microg L(-1) with an enrichment factor of 27.9 for a 3.0 mL sample consumption. The relative standard deviations (RSDs) (C(V(V))=C(V(IV))=5.0 microg L(-1), n=9) were 4.3% and 4.0% for V(V) and total V, respectively. The developed method was validated by the determination of V(IV) and V(V) in environmental water samples.

Dispersive liquid phase microextraction (DLPME) combined with graphite furnace atomic absorption spectrometry (GFAAS) for determination of trace Co and Ni in environmental water and rice samples.

A new method of dispersive liquid phase microextraction (DLPME) combined with graphite furnace atomic absorption spectrometry (GFAAS) was proposed for the determination of trace Co and Ni using 1-(2-pyridylazo) 2-naphthol (PAN) as chelating reagent. Several factors influencing the microextraction efficiency of Co and Ni and their subsequent determinations, such as pH, extraction and disperser solvent type and their volume, concentration of the chelating agent, extraction time and ashing temperature and atomization temperature were studied, and the optimized experimental conditions were established. After extraction, the enrichment factors were 101 and 200 for Co and Ni, respectively. The detection limits of the method were 21 and 33pg/mL for Co and Ni, and the relative standard deviations (R.S.Ds.) for five determinations of 0.5ng/mL Co and Ni were 7.5% and 8.2%, respectively. The results for the determination of Co and Ni in East Lake water, Yangtse River water, Dongbei rice and spiked samples have demonstrated the accuracy, recovery and applicability of the proposed method. To validate the proposed method, two certified reference materials of Environment Water (GSBZ50009-88) and NIES No.10-b rice flour were analyzed, and the determined values were in good agreement with the certified values.

Microcolumn packed with YPA(4) chelating resin on-line separation/preconcentration combined with graphite furnace atomic absorption spectrometry using Pd as a permanent modifier for the determination of trace mercury in water samples.

A new method using a microcolumn packed with YPA(4) chelating resin as solid-phase extractor has been developed for the separation and preconcentration of trace Hg prior to its measurement by GFAAS with Pd as a permanent modifier. Various parameters such as the amount of the modifier, pH, sample flow rate, the concentration and volume of eluent have been studied in order to find the best conditions for the determination of mercury. The detection limit of the method (3sigma) for Hg based on an enrichment factor of 100 was 0.2ngml(-1). A characteristic mass of 114pg was obtained for mercury using Pd as a permanent modifier. The relative standard deviation was 2.8% at the 10ngml(-1) level (n=5). The method has been applied to the determination of trace mercury in environmental water samples and the recoveries for the spiked samples are in the range of 91-105%.

[Study on the adsorption behavior of Ga, In and Tl on nanometer-size titanium dioxide by ICP-AES].

The adsorption behavior of nanometer TiO2 towards Gallium (Ga) Indium (In) and Thallium (Tl) was investigated with inductively coupled plasma atomic emission spectrometry (ICP-AES). The optimum conditions for adsorption were studied in detail, and the test included sorption kinetics, effect of pH on adsorption ratio, enrichment factor, and adsorption capacity. Under the optimum conditions, Ga (III), In(III) and Tl(I) ions could be adsorbed and recovered quantitatively. The static adsorption capacities of Ga(III), In(III) and Tl(I) on nanometer TiO2 were 48.6, 46.6 and 23.4 mg x g(-1) respectively. For the elution of Ga(III), In (III) and Tl(I), a mixture of 0.1 mol x L(-1) EDTA solution and 1.0 mol x L(-1) HNO3 was used, and the recovery ratio was above 92%. According to the definition of IUPAC, the detection limits (3sigma) of this method for Ga, In and Tl with an enrichment factor of 12.5 are 3.0, 6.0 and 13 ng x mL(-1), respectively; and relative standard deviations (RSD) are 1.85%, 1.96% and 3.4%, respectively (n = 6). The proposed method has been applied successfully to the analysis of geological samples with satisfactory results.