To the Editor:Type 2 diabetes(T2D)and cholelithiasis are both common diseases with a high,prevalence.In China,the,prevalence of T2D,is.0.90% and that offadult cholelithiasis is 6.83%.
Objective:To establish a rapid analysis method for the activity concentration of carbon-14(14C)in urine,in order to estimate the internal dose of 14C exposure,and to protect the health of occupational population.Metho...Objective:To establish a rapid analysis method for the activity concentration of carbon-14(14C)in urine,in order to estimate the internal dose of 14C exposure,and to protect the health of occupational population.Methods:Liquid scintillation counting(LSC)combined with the function of transformed spectral index of the external standard spectrum(tSIE)was used to measure the quenching level and counting rate,and the spiked urine samples with different shades of color were measured by LSC.After establishing the efficiency-quenching curve,the quenching correction and activity concentration analysis of the actual samples were carried out.Results:By LSC and the data fitting,the relationship between efficiency and quenching index could be represented using the equation y=0.0013x-0.0177(R^(2)=0.978).Three actual spiked samples were tested to verify this method,with recoveries of 97%,102%,and 89%,respectively.14C activity concentration of 4 actual urine samples were 0.12,0.11,0.10 and 0.08 Bq/mL,respectively,while the corresponding extended relative uncertainties were 0.0652,0.0929,0.0893 and 0.1043,respectively.Conclusion:The direct analysis method of 14C activity concentration in urine samples was established using LSC.The recovery of 14C activity concentration in urine samples showed that the proposed method had relatively high accuracy.By studying on the source of uncertainty,the uncertainty of the analysis results mainly came from the statistical error of LSC,and the uncertainty component of counting efficiency.展开更多
Objective:To figure out the source of uncertainty in the determination of ^(14)C activity concentration in urine samples,and to establish a complete expression of analysis results,in order to improve the accuracy of ^...Objective:To figure out the source of uncertainty in the determination of ^(14)C activity concentration in urine samples,and to establish a complete expression of analysis results,in order to improve the accuracy of ^(14)C monitoring method.Methods:Four urine samples of normal people were collected,and wet oxidation method was used in the pretreatment of the samples,then the activity concentration of ^(14)C was determined by liquid scintillation counting(LSC).After the mathematical model was established,the uncertainty components were determined,the standard uncertainty was combined,and the extended uncertainty was calculated.Results:The relative uncertainty of 4 samples was 22.5%,17.0%,17.3%and 18.2%.The activity concentration of urine was(0.32±0.14),(0.60±0.20),(0.86±0.30)and(0.74±0.27)Bq/L,respectively.In the relative uncertainty of 22.5%,17.7%was from sample counting,13.6%from detection efficiency,2.1%from recovery rate,0.58%from sample volume,and 0.01%from sample weight.Conclusions:The main factors affecting the uncertainty include the error or deviation of sample counting,detection efficiency and recovery rate.The error of volume and weight also contributes to the measurement uncertainty.展开更多
Objective:To explore the separation condition for 90Sr using crown ether resin,in order to establish a fast method for analysis of 90Sr in food and environmental samples.Methods:Stable strontium isotope(88Sr)was used ...Objective:To explore the separation condition for 90Sr using crown ether resin,in order to establish a fast method for analysis of 90Sr in food and environmental samples.Methods:Stable strontium isotope(88Sr)was used to simulate the radioactive 90Sr,and the concentration of 88Sr in elution solution was detected using inductively coupled plasma mass spectrometry(ICP–MS).The separation conditions were investigated through batch experiment.Results:Under the optimized experimental conditions,the maximum adsorption capacity of crown ether resin was 22.28 mg/g.4.0–8.0 mol/L nitric acid made it easier for the Sr2þto load on the resin,and 20 mL ultrapure water was used to rinse the chromatographic column to achieve a good separation effect,by which the recoveries of Sr2þwere nearly close to 100%.The average recovery rates of 4 samples were 60.25%,69.26%,75.09%and 66.33%,respectively.Conclusions:Crown ether resin has very good selectivity and adsorption for 90Sr.The optimized conditions were high-efficiency and easy to operate.The separation method has great potential for the fast analysis of 90Sr in food and environmental samples.展开更多
基金This research was supported by grants form the Beijing Natural Science Foundation(Nos.7192240,7224351)the National Natural Science Foundation of China(No.81900386)the Peking University Shougang Hospital(Nos.SGYYZ201701,SGYYQ201903).
文摘To the Editor:Type 2 diabetes(T2D)and cholelithiasis are both common diseases with a high,prevalence.In China,the,prevalence of T2D,is.0.90% and that offadult cholelithiasis is 6.83%.
基金This work was supported by ERAN I-21-18,Key Program of Tianjin Municipal Natural Science Foundation(19JCZDJC40500)Key Program of National Center for Occupational Safety and Health(2021-ZD-06).
文摘Objective:To establish a rapid analysis method for the activity concentration of carbon-14(14C)in urine,in order to estimate the internal dose of 14C exposure,and to protect the health of occupational population.Methods:Liquid scintillation counting(LSC)combined with the function of transformed spectral index of the external standard spectrum(tSIE)was used to measure the quenching level and counting rate,and the spiked urine samples with different shades of color were measured by LSC.After establishing the efficiency-quenching curve,the quenching correction and activity concentration analysis of the actual samples were carried out.Results:By LSC and the data fitting,the relationship between efficiency and quenching index could be represented using the equation y=0.0013x-0.0177(R^(2)=0.978).Three actual spiked samples were tested to verify this method,with recoveries of 97%,102%,and 89%,respectively.14C activity concentration of 4 actual urine samples were 0.12,0.11,0.10 and 0.08 Bq/mL,respectively,while the corresponding extended relative uncertainties were 0.0652,0.0929,0.0893 and 0.1043,respectively.Conclusion:The direct analysis method of 14C activity concentration in urine samples was established using LSC.The recovery of 14C activity concentration in urine samples showed that the proposed method had relatively high accuracy.By studying on the source of uncertainty,the uncertainty of the analysis results mainly came from the statistical error of LSC,and the uncertainty component of counting efficiency.
基金supported by ERAN I-21-18,Key Program of Tianjin Municipal Natural Science Foundation(19JCZDJC40500)Key Program of National Center for Occupational Safety and Health(2021-ZD-06).
文摘Objective:To figure out the source of uncertainty in the determination of ^(14)C activity concentration in urine samples,and to establish a complete expression of analysis results,in order to improve the accuracy of ^(14)C monitoring method.Methods:Four urine samples of normal people were collected,and wet oxidation method was used in the pretreatment of the samples,then the activity concentration of ^(14)C was determined by liquid scintillation counting(LSC).After the mathematical model was established,the uncertainty components were determined,the standard uncertainty was combined,and the extended uncertainty was calculated.Results:The relative uncertainty of 4 samples was 22.5%,17.0%,17.3%and 18.2%.The activity concentration of urine was(0.32±0.14),(0.60±0.20),(0.86±0.30)and(0.74±0.27)Bq/L,respectively.In the relative uncertainty of 22.5%,17.7%was from sample counting,13.6%from detection efficiency,2.1%from recovery rate,0.58%from sample volume,and 0.01%from sample weight.Conclusions:The main factors affecting the uncertainty include the error or deviation of sample counting,detection efficiency and recovery rate.The error of volume and weight also contributes to the measurement uncertainty.
基金This work was supported by the National Key Research and Development Program of China(No.2017YFC1601602)Environmental Radioactivity Research Network Center(ERAN I-21-18)+1 种基金Key Program of Tianjin Municipal Natural Science Foundation(No.19JCZDJC40500)Program of National Center for Occupational Safety and Health(No.2020010).
文摘Objective:To explore the separation condition for 90Sr using crown ether resin,in order to establish a fast method for analysis of 90Sr in food and environmental samples.Methods:Stable strontium isotope(88Sr)was used to simulate the radioactive 90Sr,and the concentration of 88Sr in elution solution was detected using inductively coupled plasma mass spectrometry(ICP–MS).The separation conditions were investigated through batch experiment.Results:Under the optimized experimental conditions,the maximum adsorption capacity of crown ether resin was 22.28 mg/g.4.0–8.0 mol/L nitric acid made it easier for the Sr2þto load on the resin,and 20 mL ultrapure water was used to rinse the chromatographic column to achieve a good separation effect,by which the recoveries of Sr2þwere nearly close to 100%.The average recovery rates of 4 samples were 60.25%,69.26%,75.09%and 66.33%,respectively.Conclusions:Crown ether resin has very good selectivity and adsorption for 90Sr.The optimized conditions were high-efficiency and easy to operate.The separation method has great potential for the fast analysis of 90Sr in food and environmental samples.
