Clevelandthornton0464

1 mg, and the samples at room temperature could be preserved for 15 days at least. selleck inhibitor Ethylenediamine, triethylenetetramine or tetraethylenepentamine coexisted in the air did not interfere during the determination of diethylenetriamine. CONCLUSION The method with low determination concentration, high accuracy and precision, is feasible for determination of diethylenetriamine in workplace air.OBJECTIVE The method for analyzing of 20 polychlorinated biphenyls(PCBs) in water by stable isotope internal standard-automatic solid-phase extraction membrane(auto SPEM) coupled to gas chromatography-mass spectrometer(GC-MS) was established, and applied to the analysis of trace PCBs in water samples. METHODS The sample backgrounds of bottled mineral water production in Fuzhou(groundwater), inland water in Fuzhou university city(surface water), tap water(pipe tip water) and stream water in Xiyuan Gong(water source of life) were analyzed by GC-MS. Surrogate solution(SS)internal standards including ~(13)C_(12 )PCBs stable isotope was used for quantification. The method was confirmed by calculating recovery rate(RR) and relative standard deviation(RSD) of spiked water samples(20, 40 and 80 ng/L, n=7). And recovery rates of SS were used to evaluate the effect of the pretreatment. And the method was used to determine PCBs of a total of 17 cross-sectiona river water in minjiang river tributaries upstream to the downstream estuary. RESULTS The method detection limits(MDL) were 1. 9-6. 6 ng/L, and RRs were 70. 9%-127%, and RSDs were 0. 5%-13%. The RRs of SS were 40%-90%. Positive sample was not detected. CONCLUSION The method of auto SPEM is less solvent, more automatic than traditional manual SPE. And the method is more accurate and reliable by stable isotope internal standard coupled to GC-MS. Therefore, it is useful for the trace PCBs determination of waters.OBJECTIVE A rapid quantitative technique had been developed for the screening of malachite green(MG) in aquaculture water using paper spray ionization mass spectrometry(PSI-MS). METHODS To rapid extract MG, chloroform and deep eutectic solvents(DESs) were used as extraction agent and co-solvent respectively. malachite green D_5(MG-D_5) was used as an internal standard to quantitative determination MG, C_(18) chromatographic column(4. 6 mm×250 mm, 5 μm). RESULTS The method showed a good linearity(R~2=0. 999) in the concentration range of 0. 1-10 μg/mL with the detection limit of 0. 03 μg/mL and the quantitative limit of 0. 1 μg/mL. The intra-and inter-day precisions were 3. 5% and 6. 2%, and the recovery ranged from 98. 9% to 106. 9%(n=7). The detection result by PSI-MS were in agreement with those by liquid chromatography-tandem mass spectrometry(LC-MS/MS), but the run time was only 1 min each sample. CONCLUSION The method is accurate and reliable. And compared with the conventional LC-MS/MS technology, it is simple, rapid and low-cost.OBJECTIVE To develop a method for determination of benzo[a]pyrene and to analysis of benzo[a]pyrene content in commercially available infant milk powder. METHODS Firstly, infant milk powder was extracted with ether-petroleum ether(1∶1, V/V) under alkaline conditions, then saponified with 1. 5 mol/L potassium hydroxide ethanol solution. After purification by solid phase extraction column, it was separated on DB-EUPAH chromatographic column(20 m×0. 18 mm×0. 14 μm) and detected by gas chromatography-mass spectrometry, and quantified using D_(12)-benzo[a]pyrene internal standard. RESULTS When the benzo[a]pyrene in infant formula was spiked 0. 3, 1. 0, 5. 0 μg/kg, the average recoveries were 116. 7%、86. 0% and 96. 4%, respectively, and the relative standard deviations were 10. 5%、4. 2% and 4. 4%, respectively(n= 6). The limit of quantification was 0. 3 μg/kg, and the detection limit was 0. 1 μg/kg. A total of 40 domestic and imported infant milk powders sold in Hangzhou supermarkets were analyzed. The range of benzo[a]pyrene was less then 0. 1-0. 25 μg/kg, and the detection rate was 32. 5%. CONCLUSION The method has the advantages of rapid operation, good purifying effect, sensitiveness and accuracy, and meets the requirements for detection of benzo[a]pyrene in infant milk powder. The investigation reveals that the benzo[a]pyrene content in the currently marketed infant milk powder is at a low level.OBJECTIVE To study the effect of curcumin on the expression of glucose regulated protein 78 kD(GRP78) and cysteinyl aspartate specific proteinase-12(caspase-12) of myocardial endoplasmic reticulum stress related factors in type 2 diabetes rats. METHODS Type 2 diabetes rats model was established by high-fat drink feeding and one-time intraperitoneal injecting streptozotocin(35 mg/kg). After model rats were built, rats was randomly divided into diabetic model group and low dose of curcumin group(200 mg/kg), high dose of curcumin group(400 mg/kg) and captopril group(60 mg/kg) with 10 rats in each group. The rats in each group were ig administered with corresponding drugs once a day. Continuous administration for 12 w. The levels of fasting blood glucose(FBG) and lactate dehydrogenase(LDH), electrocardiogram and heart weight index(HWI) were measured respectively. The myocardial pathological changes were observed by HE staining. The levels of collagen fiber expression in myocardial tissue were performed by Masson staining. The protein expression levels of GRP78 and caspase-12 in myocardium of rats were observed by immunohistochemistry. RESULTS The result showed that compared with control group, the levels of FBG and LDH of serum were increased obviously, HWI was increased, myocardial cells were hypertrophy, the collagen fibers of intercellular space of cell were increased, the protein expressions of GRP78 and caspase-12 of myocardium were increased in rats, myocardial cell apoptosis was increased in the model group(P less then 0. 05). Compared with model group, FBG and LDH levels and HWI were reduced, the collagen fiber of intercellular space were decreased, the protein expression levels of GRP78 and caspase-12 were lowered in high dose of curcumin group(P less then 0. 05). CONCLUSION It indicates that Cur defends myocardium tissue in type 2 diabetes rats, which may be related to decreasing the level of blood glucose and the protein expressions of GRP78 and caspase-12, and blocking the ERS-initiated apoptotic.