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Objective To evaluate the method for detection of urinary mercury using a Zeeman atomic absorption mercury analyzer and to provide a reference for selecting a convenient method for mercury detection in experiments and clinical diagnoses. Methods Urinary mercury was detected by Zeeman atomic absorption spectroscopy (ZAAS) and hydride generation atomic absorption spectrometry (HG-AAS), and the detection limit, accuracy, precision and consistency of the two methods were compared. Results The Data collected by ZAAS and HG-AAS showed a good linear relationship in the range of 0 -1000 ng/mL (ZASS, R2 =1. 0000) and 0 -20 ng/mL (HG-AAS, R2 =0. 9990). The detection limits of ZAAS was 0. 156 ng/mL and that of HG-AAS was 1. 593 ng/mL, indicating that ZAAS is more sensitive. The recovery rate of standard addition of ZAAS was between 97. 5％ and 103. 2％, and that of HG-AAS was between 95. 6％ and 104. 5％. After measurement of 10 ng/mL and 100 ng/mL mercury standard solutions repeated for 10 times, the relative standard deviation (RSD) of ZAAS was 0. 30％ and 0. 36％ respectively, and the RSD of HG-AAS was 2. 82％ and 1. 11％, respectively. The accuracy and precision of both the two method met the standards of GBZ/T 210. 5-2008, and the precision of ZAAS was better. A total of 30 urine samples were measured by these two methods. The results were compared with paired-samples t-test and showed a non-significant difference (P ＞ 0. 05), indicating a high consistency of these two method (R2 =0. 9961). Conclusions ZAAS is a convenient and accurate method for the detection of urinary mercury, with a relatively low detection limit and better precision.
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Objective: To develop a method for the determination of lacidipine (LAC) in human plasma.Methods: After liquid-liquid extraction with tert-butyl methyl ether, the plasma samples were analyzed by LC-MS/MS.Using lacidipine-13C8 as the internal standard, a Agilent ZORBAX Eclipse XDB C18 column (150 mm×2.1 mm, 5 μm) was used with the mobile phase consisting of water(containing 5 mmol·L-1 ammonium formate)-acetonitrile(15∶85,v/v)at a flow rate of 0.3 ml·min-1 and with the column temperature at 40 ℃.The ion transitions were performed in a positive electrospray ionization multiple reaction-monitoring mode regarding + as the molecular ion peak of lacidipine and monitoring with m/z 473.5→m/z 410.3, m/z 473.5→m/z 400.1 and m/z 473.5→m/z 354.3.The internal standard was monitored with m/z 481.4→m/z 362.3.Results: The linear range of lacidipine was 0.1-10 ng·ml-1 (r＞0.99) and the lower quantification limit was 0.1 ng·ml-1.The intra-and inter-day RSDs were 3.15%-7.04% and the relative error was from-8.58% to 12.71%.The mean relative recovery of lacidipine was from 107% to 118% (RSD＜15%).The plasma samples were stable at-20℃ for 40 d and kept stable after three repeated freeze-thaw cycles.The prepared samples were stable at room temperature for 24 h and in the automatic sample injector (4℃) for 24 h(RSD＜15%).Conclusion: The developed assay method can be applied in the bioequivalence evaluation and pharmacokinetic studies of lacidipine in human.
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Objective To use the colloidal gold immunochromatography (GICA ) method to conduct the methodological prelimi-nary evaluation on pepsinogen Ⅰ (PGI) reagent kit .Methods The method provide by the Preliminary Evaluation of Clinical Quan-titative Experimental Methods :Approval Guide Second Edition (EP10-A2) formulated according to the Clinical Laboratory Stand-ards Institute (CLSI) was used to continuously detect the low ,moderate and high concentrations of serum for 5 d ,Then the related data were collected for analyzing the dispersion degree ,linearity ,offset ,precision and so on .Results The PGⅠ quality control ser-um (concentration 25 ,50 ,100 μg/L) was detected at low ,medium and high concentration levels ,the linear regression equation ob-tained by analysis was Y=0 .9939X+0 .7433 ,correlation coefficient (R2 )=0 .9992 ;the offsets were 0 .37 ,0 .77 ,0 .78 μg/L re-spectively ,total imprecision was 3 .04% ,1 .17% and 1 .08% respectively .Conclusion The GICA related technical indicators of PGⅠreagent kit reach the standards of EP10-A2 document ,the detection results are accurate with high sensitivity and good stability , and conform to the requirements of clinical applications .
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Objective To investigate the precision, trueness, and accuracy of self-developed detection system in clinical chemistry.Methods This was a methodological evaluation.Take serum creatine kinase( CK) for instance, 6 serum sampleswith different leves ( on the upper or lower limit of the reference range or close to the medicine decide levels ( MDLs) , were collected for within-run precision( repeatability) and within-laboratory precision ( intermediate precision ) experiments.5 proficiency testing ( PT ) samples, 5 samples assigned value by reference method, and 40 fresh-frozen serums were measured and compared with reference method for trueness verification.Drawing method evaluation decision chart, calculating total errors and sigma level evaluation experiment based on the CV, bias, and allowed total errors(TEa)were used to evaluate the accuracy performance.The precision, trueness, and accuracy were compared with the quality indicators.Results The within-run precision and within-laboratory precision were less than the highest requirement of Chinese industrial standard.The mean bias was -8.96%, didn′t reachthe required standard (5.5%).After taking corrective actions, all samples but one ( -5.8%) met the required standard. Compared with the reference method, the mean bias on the MDLs was less than TEa.The performance points of the method evaluation decision chart indicated excellence performance.The total errors on MDLs were 14.2%, 10.4% and 7.6%, less than 15%.The sigma levels on MDLs were 5.9, 7.5 and 15, also achieved excellent level. Conclusions The precision, trueness, and accuracy performance of CK measured by self-developed detection system achieved excellent level of the Chinese industry standard, and the same results were found from different evaluation methods.
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Objective:To validate an enzyme linked immunosorbent assay (ELISA) method for the quantification of rhCNB in long-tailed macaque sera.Methods: The linear,sensitivity,accuracy,precision and recovery were determined using ELISA.Results:The present ELISA method had high linearity within 0.195 ng/ml-12.5 ng/ml,the working curve of rhCNB was Y=15.1X-0.26, R2=0.996 8 , the method showed good sensitivity of 0.195 ng/ml, the accuracy were in the range of 91.9%-108.8%, and the Coefficient of variation ( CV) for inter-assay were 3.55%,1.39%and 4.71%,the intra-assay were 1.59%,3.2%and 3.8%,all less than 10%, the recoveries were in the range of 88.5% -108.3%, <110% .Thus the method was coincidence with requirement.Conclusion:Double antibody sandwich ELISA assay of rhCNB in long-tailed macaque sera has good sensitivity ,accuracy, precision and recovery and it can be used to measure rhCNB concentration in biological samples .
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Objective To establish a continuous monitoring assay of serum argininosuccinate lyase (ASL) activity with automatic biochemistry analyzer, and perform methodology validation and preliminary clinical application.Methods According to the chemical reaction catalyzed by ASL and the working characteristics of automatic biochemistry analyzer, an enzyme coupled reaction system with high specificity was set up, and the methodology validation was performed.Three hundred and nine patients with various liver diseases, 269 non-liver disease patients and 40 healthy controls were enrolled in this study.Serum ASL, ALT, and AST level were determined in all subjects.Results A new kinetics assay of ASL activity was set up with automatic biochemistry analyzer.The methodological validation demonstratod that inter-assay and intra-assay coefficient of variation were 4.0% and 5.9% respectively and the mean recovery was 100.5%.The linear range was 0-167.7 U/L.The lowest detection limit was approximately 0 U/L.The interference test showed that there is no significant interferences while the concentration of bilirubin is less than 342 μmoL/L or commonly used anticoagulants is employed at their routine concentrations.However,interference was significant when Hb level is more than 0.06 g/L.Preliminary study of clinical application showed that there was no significant difference of serum ASL level between non-liver disease group and healthy group ( q = 0.027, P = 0.979 ), but there was significant differences for both serum ALT and AST levels (ALT:q =6.461,P =0.000;AST:q =6.481,P =0.000).Conclusions A continuous monitoring assay for the determination of serum ASL activity is successfully established. Serum ASL may be a good biomarker for liver injury.