Objective To develop a high performance liquid chromatography (HPLC) method for the determination of nicotine in tobacco. Methods The nicotine was separated completely by C18 column (column temperature∶35℃ ), and was determined by PDA detector at wave length of 260 nm. Mobile phase was acetonitrile: 0.08 mmol/L KH2PO4 (V∶V= 1∶9) at the flow rate of 1.0 ml/min. Results The detection limits is 0.40 ?g/ml. The linear range was 0.00-60.0 ?g/ml. The recovery rates were 97.8%-103% and the relative standard deviations was 2.29% (n=5). Conclusion The method was simple, rapid, sensitive and accurate for the determination of nicotine.

0.992 7. The recovery rates were 80.0%-107% and the RSDs were between 0.16%-1.69%. Conclusion This method is simple, rapid, sensitive, accurate and is applicable to the simultaneous determination of carbonyl compounds in water.

A method was developed for the determination of four kinds of bisphenolic and halogenated bisphenolic compounds including bisphenol F, bisphenol A, tetrachlorobisphenol A, tetrabromobisphenol A in human urine using high performance liquid chromatography-tandem mass spectrometry. The analytes was extracted by solid phase extraction. The separation of the analytes was achieved on an Atlantis T3 column (3. 0×150 mm, 3 μm) gradient eluted with the mobile phase of acetonitrile and water at the rate of 250 μL/min, and detected by an electrospray ionization tandem mass spectrometry in the multiple-reaction-monitoring negative mode. The quantification was carried out by matrix-matched calibration curve. The average recoveries at 3 spiked levels were 86%-118%, with intra-day precision of 2 . 6%-17 . 0% and inter-day precision of 3. 2%-18. 0%. The limits of detection of four analytes (S/N=3) were 0. 01-0. 25 μg/L. The method was applied to the analysis of 200 human urines samples and the results showed that the method was simple, sensitive and reliable.

Anemia, Sideroblastic ; diagnosis ; genetics ; Asian Continental Ancestry Group ; Genetic Diseases, X-Linked ; diagnosis ; genetics ; Humans ; Pedigree

OBJECTIVEIn order to study the relation between polymorphisms of methylenetetrahydrofolate reductase C677T (MTHFR) and susceptibility of stomach cancer (SC).

METHODSWe conducted a case-control study with 107 cases of SC and 200 population-based controls in Huaian city of Jiangsu province, China. The epidemiological data were collected, and DNA of peripheral blood leukocytes was obtained from all of the subjects. MTHFR genotypes were detected by PCR-RFLP method.

RESULTS(1) The frequency of MTHFR variant genotypes (C/T + T/T) among the cases (79.4%) was significantly higher than the controls (68.5%) (P = 0.041 6); the crude OR for SC was 1.78 (95% CI: 0.99 - 3.22). After adjustment for sex and age, the OR for SC was 1.89 (95% CI: 1.08 - 3.32). (2) Subjects who had MTHFR variant genotypes and having smoking habit were at a significantly higher risk of developing SC (OR = 7.72, 95% CI: 2.23 - 26.79) compared with those who had wild-type homozygotes (C/C) genotype and no smoking habit. Individuals who had variant genotypes and who had habit of frequent alcohol drinking were at an increased risk of developing SC (OR = 3.08, 95% CI: 1.30 - 7.23) compared with those with C/C genotype and low consumption of alcohol. As compared with subjects with C/C genotype and low consumption of alcohol and no smoking habit, individuals who had variant genotypes and who had habits of frequent alcohol drinking and smoking had 12.96 (95% CI: 2.76 - 70.46) folds risk developing SC.

CONCLUSIONSThese results in the present study suggested that the polymorphisms of MTHFR C677T was associated with risk of developing SC, and there was a coordinated effect between MTHFR genotypes and habits of smoking and alcohol drinking in the development of SC.

Alcohol Drinking ; Female ; Genetic Predisposition to Disease ; Humans ; Male ; Methylenetetrahydrofolate Reductase (NADPH2) ; Middle Aged ; Oxidoreductases Acting on CH-NH Group Donors ; genetics ; Point Mutation ; Polymorphism, Genetic ; Risk Factors ; Smoking ; Stomach Neoplasms ; epidemiology ; genetics