ABSTRACT
Objective To establish a kind of simple,rapid,accurate and reliable method to analyze the concentration of alcohol in blood by headspace gas chromatography (HS-GC) with dual-column and dual-detector.Methods The samples were pre-treated by headspace sampler,which was the basis on the extraction principle of the gas extracting volatile substances.Next,these samples were analyzed by HS-GC that the tertiary butyl alcohol was acted as the internal standard substance.The HS-GC was equipped with two chromatographic column (the DB-ALC2 chromatographic column of 001 channel;the DB-ALC1 chromatographic column of 002 channel).At the same time,the HS-GC was also equipped with two hydrogen flame ionization detector (FID1 detector;FID2 detector).The retention time of the peak was finally performed as qualitative parameter and the standard curves method of internal standard were acted as quantitative basis.Results The liner range of the method was 0.2-2.0 mg/mL.The linear regression equation of 001 channel was Y=1.057 7X+0.048 2 and the correlation coefficient was R2=0.999 05.Besides,the linear regression equation of 002 channel was Y=1.039 5X+0.046 5 and the correlation coefficient was R2=0.999 25.In short,the average recovery rate of the method was 99.70%.Relative standard deviation(RSD) was less than 4% between the analysis results of 001 channel and 002 channel for the determination of the plan sample.Conclusion The method shown satisfactorily that it could not only be applied to determine the alcohol of blood of forensic toxicological analysis,but also be applied to determine the plan sample of ability test and verify of laboratory ability accreditation.
ABSTRACT
Objective:According to the technical standard of ISO and current regulations in China, the X/γ standard calibration quality for the finger-ring dosimeter irradiation was established in Beijing SSDL, it can ensure the traceability of surveillance data within countrywide.Methods: Air kerma-rate was determined in the X-ray beams,137Cs and60Co by a standard dosimeter, combined transfer coefficientHp(0.07) provided by standards, and confirmed condition of X/γ standard calibration quality for the finger-ring dosimeter irradiation. Using finger-ring TLD dosimeter verified the radiation beam qualities Hp on the ISO finger-phantom.Results: The linearity and energy response of the TLD dosimeter met ISO and national standard in Beijing SSDL.Conclusion: The X/γ standard radiation field can be used for the calibration of finger-ring dosimeter standard curves and experiment of research, and can further promote the comparability and reliability of the surveillance data.
ABSTRACT
Objectives: The purposes of this paper were to evaluate the serum leptin levels in healthy adolescents and to establish standard age variation curves. Methods: Nine hundred six (414 boys and 492 girls) healthy adolescents were investigated. The maximum increment age in height (MIA) was identified in 124 boys and 130 girls. The menarcheal age (MA) was obtained for 130 girls. Fasting leptin levels were measured by enzyme immunoassay. The MIA was calculated by proportional allotment of yearly height increments. Results: Serum leptin levels did not change in boys and girls from the ages of 9 to 11. They decreased after the age of 11 in boys, while they increased in girls. Stepwise multiple regression analysis revealed that serum leptin levels were closely related to pubertal stage. The levels decreased remarkably after MIA in boys and increased remarkably after MA in girls. We drew standard age variation curves of serum leptin levels by calculating the 25th, 50th and 75th percentiles for each age in both boys and girls. The percentile curves for boys were divided into pre-MIA and post-MIA curves. Those for girls were divided into pre-MA and post-MA curves. Conclusion: We have devised a potentially useful method for evaluating serum leptin levels in adolescents considering the effects of gender and growth.
Subject(s)
Leptin , Serum , Gender IdentityABSTRACT
<p><b>OBJECTIVES</b>The purposes of this paper were to evaluate the serum leptin levels in healthy adolescents and to establish standard age variation curves.</p><p><b>METHODS</b>Nine hundred six (414 boys and 492 girls) healthy adolescents were investigated. The maximum increment age in height (MIA) was identified in 124 boys and 130 girls. The menarcheal age (MA) was obtained for 130 girls. Fasting leptin levels were measured by enzyme immunoassay. The MIA was calculated by proportional allotment of yearly height increments.</p><p><b>RESULTS</b>Serum leptin levels did not change in boys and girls from the ages of 9 to 11. They decreased after the age of 11 in boys, while they increased in girls. Stepwise multiple regression analysis revealed that serum leptin levels were closely related to pubertal stage. The levels decreased remarkably after MIA in boys and increased remarkably after MA in girls. We drew standard age variation curves of serum leptin levels by calculating the 25th, 50th and 75th percentiles for each age in both boys and girls. The percentile curves for boys were divided into pre-MIA and post-MIA curves. Those for girls were divided into pre-MA and post-MA curves.</p><p><b>CONCLUSION</b>We have devised a potentially useful method for evaluating serum leptin levels in adolescents considering the effects of gender and growth.</p>