OBJECTIVE: To improve the determination method of terbinafine hydrochloride by non-aqueous potentiometric titration.METHODS: Potentiometric titration was adopted to determine the content of terbinafine hydrochloride using glacial acetic acid as solvent,acetic anhydride instead of mercury acetate.Results of improved determination method were compared with that of primary method.RESULTS: One abrupt change was obtained in the titration curve.The repeatability precision RSD was lower than 0.15%.Results of improved determination method were compared with that of primary method with maximum deviation of 0.1%.CONCLUSION: Improved method not only discards mercuric salt but also obtain obvious abrupt change of titration curve.It is simple and rapid for the determination of terbinafine hydrochloride.

Corin is a newly identified membrance protease which responsible for converting pro-B-type natriuretic peptide to biologically active B-type natriuretic peptide.B-type natriuretic peptide play an important role in regulating blood pressure and cardiac function.It is a biological marker of heart failure.So Corin plays a role in reducing blood volume, blood pressure, regulating body fluid balance, and improving cardiac function.Corin may be used as a biomarker for heart failure or other cardiovascular disease.Recent studies have found that Corin is associated with the occurrence and development of cardiovascular diseases, such as heart failure and acute coronary syndrome.The article mainly expound the biological characteristics of Corin, testing methods and its clinical application in cardiovascular disease status.

OBJECTIVE:To investigate the similarity of dissolution curves between generic preparations and reference prepara-tions of Bisacodyl enteric-coated tablets in various dissolution mediums,and to provide reference for improving production technolo-gy and internal quality of generic preparations. METHODS:Paddle method was adopted with rotation speed of 75 r/min. The disso-lution test was performed using 1000 mL pH 6.0 phosphate buffer solution,pH 6.8 phosphate buffer solution,water containing 2% sodium lauryl sulfate. HPLC method was used to determine average accumulative dissolution of main components from 3 kinds of generic preparations and reference preparations at different time points to draw out dissolution curves. Similarity factor(f2)meth-od was used to the similarity of dissolution curves. RESULTS:Dissolution curves of reference preparations were basically the same in 3 kinds of dissolution mediums. But the dissolution curve f2 of one generic preparation among 3 manufactures to dissolution curve of reference preparation were ≥50,namely the similarity. CONCLUSIONS:The quality of generic Bisacodyl enteric-coat-ed tablets produced by different manufacturers is obviously different;the generic preparations needs to be further improved in the production technology and internal quality. For domestic generic preparation,it is necessary to strengthen the real-time monitoring of its dissolution curve,to ensure the drug quality.

Hydrogen evolution from water electrolysis is one of the effective ways to obtain clean hydrogen energy in the future. Pt-based materials are the efficient catalysts in hydrogen evolution reaction, but it is expensive, difficult to recycle, which impedes its application in the development of hydrogen energy and economy. Therefore, it is the key trend to develop efficient non-noble metal electrocatalysts with the aim of providing cost-competitive hydrogen energy. In this review, we highlighted the recent research efforts toward the synthesis of noble metal-free electrocatalysts for the hydrogen evolution reaction ( HER) , mainly focusing on nanomaterial catalysts supported on carbon fiber materials. We reviewed several important kinds of heterogeneous non-noble metal electrocatalysts, including sulfides, selenides, carbides, phosphides, and oxides. In the discussion, emphasis was given to the synthetic methods of these HER electrocatalysts, and the strategies for performance improvement. In addition, this paper also briefly summarized the application of carbon fiber material as substrate in the field of electroanalytical chemistry.

OBJECTIVE:To establish a method for simultaneous residual determination of dichloromethane and ethyl acetate in bisacodyl raw material. METHODS:Head-space GC was performed on the capillary column of 6% cyanopropyl phenyl-94% di-methyl polysiloxane(DB-624)by temperature programming,the temperature of injector was 220 ℃,detector was flame ionization detector with temperature of 250 ℃,carrier gas was high purity nitrogen with the flow rate of 3.0 ml/min,split ration was 1∶10, headspace heating temperature was 70 ℃,equilibration time was 30 min,volume of headspace vial was 5 ml,and the injection volume was 1 ml. RESULTS:The linear range was 6-120μg/ml for dichloromethane(r=0.999 9)and 50-1 000μg/ml for ethyl ac-etate(r=0.999 9);the limit of quantitation was 0.2,1.7 μg,limit of detection was 0.06,0.5 μg;RSDs of precision,stability and reproducibility tests were no higher than 3%;recoveries were 100.30%-102.00%(RSD=0.63%,n=9) and 100.10 %-101.30%(RSD=0.44%,n=9). CONCLUSIONS:The method is simple and accurate,and can be used for the simultaneous residual deter-mination of dichloromethane and ethyl acetate in bisacodyl raw material.

Objective: To establish a GC method for the determination of content and content uniformity of memantine hydrochloride dispersible tablets.Methods: The sample was dissolved in water, alkalified by sodium hydroxide solution and extracted by methylene chloride.An HP-5 gas chromatography column (50 m×0.32 mm, 1.05 μm) was used.The column temperature was programming increased, and the initial temperature maintained at 120 ℃ for 3 min, and then raised to 220 ℃ at a rate of 10℃·min-1 and maintained for 7 min.A hydrogen flame ionization detector (FID) was used and the split ratio was 1∶1.The inlet temperature was 230 ℃ and the detector temperature was 260 ℃.The injection volume was 1 μl and the carrier gas was nitrogen with high purity at a flow rate of 3.0 ml·min-1.Adamantane was used as the internal standard, and the internal standard method was used for the calculation.Results: The calibration curve was linear over the range of 0.05-1.0 mg·ml -1 (r=0.999 7).The detection limit and the limit of quantification was 1.1 ng and 3.3 ng, respectively.The average recovery was 100.2% (RSD =0.73%, n=9).Conclusion: The method has the advantages of simple operation, small extraction process toxicity, little environmental pollution, high accuracy and high specificity, and can be used for the determination of content and content uniformity of memantine hydrochloride dispersible tablets.

Objective To evaluate the performances of high-sensitivity cardiac troponin I ( cTnI ) on VITRO ECIQ with enhanced chemiluminescence method .Methods This verification study validated the limited of detection,function sensitivity,imprecision,linearity of the high-sensitivity cardic troponin used VITROS ECIQ according to the document EP-17A, EP-6A,EP-15A published by Clinical and Laboratory Standards Institute (CLSI) and determined 99th percentiles.All 652 patients with chest pain on immediate admission in TEDA International Cardiovascular Hospital during January to November 2013 were enrolled in this study.Including 323 cases of acute ST segment elevation myocardial infarction and non ST segment elevation myocardial infarction patients as the case group , exclude 329 cases of other diagnosis ,303 cases of apparent normal people as control group .The receiver operating characteristic curve was used to evaluated the sensitivity and the specificity of cTnI . Non-normal distribution of quantitative data were used nonparametric test Mann-Whitney U, With P<0.05 for the difference was statistically significant .Results The LoB was 0.006 5 ng/ml and the LoD was 0.015 5 ng/ml;the FS was 0.016 76 ng/ml;repeatability CV
was 1.73 % -2.33 %, reproducibility CV was 4.93% -9.96%.The imprecision were lower than that declared by assay producer.The linearity was 0.015 5-78.4 ng/ml(R2 =0.999 9); the 99th percentile reference value was 0.017 ng/ml.The area under the curve ( AUC) of cTnI was 0.986,95%CI 0.973 -0.994,with the cut-off value as 0.017 ng/ml, the diagnostic sensitivity and specificity in CIN were 90.09%and 99.34%.Compared between STEMI and NSTEMI groups after admission , the levels of cTnI had no significantly difference , Z were -0.485, P >0.05;compared between STEMI and control groups after admission, the levels of cTnI had significantly difference , Z were -19.567,P<0.001;compared between NSTEMI and control groups after admission , the levels of cTnI had significantly difference , Z were-14.598,P<0.001.Conclusions High-sensitivity cardiac troponin I detection by VITROS ECIQ with enhanced chemiluminescence method has good performances of sensitivity , linearity, specificity, which meet the clinical needs.

OBJECTIVE:To establish the purity determination of bisacodyl by differential scanning calorimetry(DSC)and the valuation of uncertainty. METHODS:DSC was conducted to detect the purity of bisacodyl and determine the optimal testing condi-tions. According to related standards,indium enthalpy change values,measurement repeatability,weighing process,instrument tem-perature deviation and system software deviation were systematically analyzed. The results were verified by HPLC. RESULTS:When the fiducial probability P was 0.95,the standard value and uncertainty of content of bisacodyl was (99.88 ± 0.06)% mea-sured by DSC. Weighing process,instrument temperature deviation and system software deviation had great effects on the total un-certainty. The result of HPLC and DSC were the same. CONCLUSIONS:The established DSC can quickly and accurately determine the chemical purity of bisacodyl. The uncertainty evaluation is reliable. Regularly calibrated and verificated equipment and strict con-trol of the weighing process will help to improve the accuracy measured by DSC;and it provides a new analysis method for the de-termination of purity of bisacodyl.

Objective:To evaluate the measurement uncertainty in the determination of sodium valproate tablets by GC with an in -ternal standard method , and determine the main sources of uncertainty .Methods:A GC internal standard method was selected to sys-tematically analyze the uncertainty in the determination of sodium valproate tablets , including the sample quantity , dilution ratio, purity and area repeatability of chromatographic peaks .Results: The expanded uncertainty of sodium valproate tablets was 2.7%, and the determination range of sodium valproate tablets was (96.3 ±2.7)%(k=2).Conclusion:The established GC internal standard meth-od for the uncertainty evaluation is reliable , which is helpful to improving the quality evaluation and control of sodium valproate tablets .