Electrogenerated chemiluminescence sensor for the determination of metoclopramide using ordered mesoporous carbon for immobilizing tris(2, 2'-bipyridyl) ruthenium

A novel electrogenerated chemiluminescence (ECL) sensor for the determination of metoclopramide was developed by employing ruthenium complex as an ECL signal producer and an ordered mesoporous carbon (OMC) material as modified material. The ECL sensor was fabricated by adsorption ruthenium complex into a mixture of OMC and Nafion, which showed good electrochemical and ECL behaviors. It was found that the ECL intensity of the sensor fabricated was greatly enhanced in the presence of metoclopramide. Based on this finding, a highly sensitive and reproducible ECL method was developed for the determination of metoclopramide. The result showed that the ECL intensity was linear with the concentration of metoclopramide in the range from 1.0×10-10 to 5.0×10-7M and the detection limit was 3×10-11M. The ECL sensor exhibited a long-term stability and a fine reproducibility with relative standard deviation of 1.0 % for 1.0×10-10M metoclopramide in 18 continuous determinations. The developed method has been applied to the determination of metoclopramide in tablet samples with satisfactory results.     

Flow-injection-enhanced chemiluminescence method for the determination of three β-blockers

Objective To develop a rapid, simple and sensitive chemiluminescence method for the determination of three β-blockers (bisoprolol, atenolol and propranolol). Methods The chemiluminescence of cerium (Ⅳ)-sulfite system was obviously sensitized by adding anyone of three β-blockers in acid media. A new chemiluminescence method was set up by combining with flow-injection technique and used to determine the three β-blockers. Results Good linear ranges were obtained at the concentrations of 2.0×10-7g/mL-4.0×10-5g/mL, 1.0×10-7g/mL-3.0×10-5g/mL and 7.0×10-7g/mL-1.0×10-5g/mL, respectively, with the detection limits of 5.0×10-8g/mL, 7.0×10-8g/mL and 5.0×10-8g/mL (S/N=3), respectively, and the relative standard deviations for 11 times consecutive injections of 1.0×10-6g/mL bisoprolol, atenolol and propranolol were 3.57%, 2.21% and 2.26%, respectively. Conclusion The developed method is sensitive, accurate, rapid and of low cost. And it can be applied to determine bisoprolol, atenolol and propranolol in pharmaceutical preparations.     

Capillary electrophoresis coupled with electrochemiluminescence for determination of cloperastine hydrochloride

Objective To investigate the electrochemiluminescence (ECL) behavior of cloperustine hydrochloride.Methods ECL intensity of tris (2,2'-bipyridyl) rutheniumo(Ⅱ) was enhanced, the method for the determination of dupernstine hydrochloride was established using capillary electrophoresis (CE) coupled with electrochemilumolinescence (ECL) detection. Results Under the optimum conditions, ECL intensity varied linearly with cloperastine hydrochloride concentration from 7.0×10-6 g/mL to 1.0×10-4 g/mL. The detection limit (S/N=3) was 8.05×10-7g/mL. he relative standard deviation of the ECL intensity and the migration time for 11 consecutive injections of 1.0 ×10-5g/mL cloperastine hydrochloride was 2.9% and 1.5%, respectively. This method was successfully applied to eloperastine hydrochloride tablet determination. Conclusion The method has been established, validated and applied for determination of cloperastine hydrochloride.     

DETERMINATION OF TETRACYCLINE AND OXYTETRACYCLINE BY FLOW-INJECTION CHEMILUMINESCENCE METHOD

Tetracycline and oxytetracycline are broad-spec-trumantibiotics.They are not only used in humanpathologies,but alsoin veterinary medicine,ani malnutrition and feed additives for cattle breeding.In the past few years,the deter mination meth-ods of tetracycline and oxytetracycline were repor-ted,which involved in difference spectrophotome-try[1],HPLC[2,3],spectrophotometry[4-7],HPLC-MS[8-9],spectrofluori metry[10],solid-phase extrac-tion[11]and kinetic methods.Recently,flow-injection CL met…     

Luminol-potassium permanganate chemiluminescence system for the determination of three anthracycline antibiotics

Objective To establish a flow-injection chemiluminescence method for the determination of doxorubicin, epirubicin and mitoxantrone and study its reaction mechanism. Methods In alkaline medium, chemiluminescence of luminol-potassium permanganate system could be inhibited obviously by anthracycline antibiotics. Combined with flow-injection technique, a new chemiluminescence method for determining the anthracycline antibiotics was set up. The chemiluminescence mechanism of the luminol-potassium permanganate system was also discussed. Results Under optimal conditions, the good linear ranges of doxorubicin, epirubicin and mitoxantrone were 5.0×10-9-1.0×10-6g/mL, 1.0×10-9-1.0×10-5g/mL and 3×10-9-1.0×10-6g/mL, respectively. The detection limits of doxorubicin, epirubicin and mitoxantrone were 3.0×10-9g/mL, 5.0×10-8g/mL and 2.0×10-9g/mL, respectively. During eleven repeated inter-day and intra-day precision tests of 1.0×10-6g/mL samples, the relative standard deviations corresponded to reference values of 3.0%, 2.8% and 2.1%. Conclusion The developed method is sensitive, accurate, rapid and of low cost. It can be applied to determine doxorubicin hydrochloride, epirubicin hydrochloride and mitoxantrone hydrochloride in injection preparations.     

Analysis of ganciclovir and its related substances using high performance liquid chromatography and liquid chromatography-mass spectrometry methods

Objective High performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC/MS) methods were developed for the determination of ganciclovir and its related substances. Methods A Hypersil ODS2 column (4.6mm×250mm, 5μm) was used with a mobile phase of 0.02M potassium 1.0mL/min, and UV detector set at 254nm was used for monitoring the eluents. Results The method was simple, rapid, selective and capable of separating all related substances at trace level with a detection limit of 0.04μg/mL. It has been validated with respect to accuracy, precision, linearity, and limits of detection and quantification. The linearity range was 10.2-153.0μg/mL with r=0.9998. The percentage recoveries ranged from 96.7% to 101.6%, and RSD was 1.24%-1.96% (n=5). Conclusion The method was found to be suitable not only for monitoring the reactions during the process development but also for quality control of ganciclovir. For identification of related substances, LC/MS was used. The mainly related substances of ganciclovir active pharmaceutical ingredients (API) were determined as guanine, (1, 3-dioxolan-4-yl) methyl acetate, and diacetyl guanine.     

RP-HPLC method for the quantitation of β-Sitosterol in Elaeagnus Gon yanthes Benth

Objective To establish an RP-HPLC method for the determination of β-Sitosterol in Elaeagnus Gonyanthes Benth. Methods The separation was performed on a luna C8 (2) (150 mm×4.6 mm, 5μm) column with the mobile phase of methanol-water (88∶12, v/v) at a flow rate of 1.0 mL/min, the detection wavelength was set at 210 nm, and the temperature of the column was maintained at 35 ℃. Results The calibration curve of β-Sitosterol was linear over the concentration range of 0.075-0.375 mg/mL (r=0.9999) and the average recovery of β-Sitosterol was 96.30% with RSD of 3.60%(n=3). Conclusion The method is simple, rapid, and accurate, and can be used for the quality control of Elaeagnus Gonyanthes Benth.     

流动注射-化学发光法测定氢化可的松

目的确定以高锰酸钾-亚硫酸钠体系测定氢化可的松的流动注射-化学发光分析方法。方法在酸性条件下,氢化可的松对高锰酸钾-亚硫酸钠体系发光反应具有明显的增敏作用。据此,建立了流动注射化学发光测定氢化可的松的分析方法。结果在优化的实验条件下,氢化可的松质量浓度在1.0×10-9-1.0×10-6g/mL范围内与发光强度呈良好的线性关系,检出限(3R)为4.0×10-10g/mL,对氢化可的松进行11次平行测定,其相对标准偏差为2.2%。结论本方法应用于注射液中氢化可的松含量的测定,快速、准确、简便,灵敏度高、线性范围宽。     

CE-ECL法同时测定复方磷酸可待因中三种成分的方法学研究

目的 建立毛细管电泳-电化学发光法分离并检测复方磷酸可待因中三种成分,磷酸可待因、马来酸溴苯那敏和盐酸麻黄碱含量的新方法.方法 基于碱性介质中,复方磷酸可待因溶液中三种主要成分对联吡啶钌在铂电极上的电化学发光信号的增敏作用,且增敏强度和药物浓度成线性关系,与毛细管电泳联用,建立了毛细管电泳-电化学发光法分离并检测其含量的新方法.结果 在优化的实验条件下,确定三种药物对照品的线性范围、线性方程和检出限.通过对浓度为1.0×10~(-5)kg/L的磷酸可待因、马来酸溴苯那敏和盐酸麻黄碱对照品进行12次平行测定,其ECL发光强度的RSD值分别为2.89%,3.76%,3.32%.结论 该方法可用于复方磷酸可待因口服溶液中三种主要成分的含量测定,待测样品中的基质不干扰测定,方法的回收率分别为100.4%,101.9%,99.8%(n=5).     

奋乃静药物的流动注射化学发光测定方法的建立

目的建立快速测定奋乃静的流动注射化学发光新方法。方法在硝酸介质中,奋乃静能被硫酸铈氧化生成发光物质奋乃静砜,从而产生化学发光。基于此,建立了奋乃静的流动注射化学发光分析方法。结果在优化的实验条件下,不用任何发光增敏剂,奋乃静在1.0×10-7-7.0×10-5g/mL范围内与化学发光强度呈良好的线性关系,检出限(3σ)为8.0×10-8g/mL,对1.0×10-6g/mL的奋乃静进行了11次平行测定,其相对标准偏差为1.8%。结论本方法简便、快速、准确、灵敏度高、线形范围宽,应用于奋乃静片剂分析,并与药典方法进行对照,结果满意。     

Preparation of recombinant firefly luciferase by a simple and rapid expression and purification method and its application in bacterial detection

A simple and rapid expression and purification method of recombinant firefly luciferase was developed for bacteria detection. A modified luciferase gene from North American firefly Photinus pyralis was cloned into pET28a expression vector and the recombinant protein was produced in Escherichia coli BL21. The recombinant luciferase, equipped with a polyhistidine affinity tag, was purified by immobilized metal ion affinity chromatography (IMAC). The approach generated an abundant expression and an efficient purification of a recombinant luciferase with final yield 1.995mg/L of cell culture. Experiments on the recombinant luciferase also showed that the relative light units (RUL) of the enzyme were 5.8×108, and the specific activity was 2.9×1010 RLU/mg. By applying adenosine triphosphate (ATP) bioluminescence to detection of the coin bacteria using the recombinant protein, the ATP content of bacteria was 9.48×10-16mol/mL, and was identical to the bacteria counts (4500CFU/mL) in order of magnitude. Taken together, our results provided a simple and efficacious method of the preparation of recombinant luciferase, which could be applied in the determination of bacteria via ATP bioluminescence.     

THE STUDY OF MICROSATELLITES ALTERATION IN DIAGNOSES OF BLADDER CANCER

Objective To investigate the possibility of microsatellite alteration （MA） in diagnosis of bladder cancer of Chinese people, and find the better panel which will be used in clinic. Methods A total of 6 and 10 microsatellite markers were chosen, PCR-SSLP silver staining assay was performed in 31 and 32 bladder cancers tissue, exfoliate cells in urine and 10, 15 non-bladder cancers exfoliate cells in urine, respectively. Results MA （＋） was found in 28 out of 31, 30 out of 32 bladder cancers, and the sensitivity was 90. 3%, 93.7% respectively. The MA of urine sediment of 25 non-bladder cancers was negative, and the specificity was 100%. The cytology was carried out among 19 out of 31, 20 out of 32 bladder cancers at the same time, 2 cases （10.3%） and 3 cases （15%） were found cancer positive, and the sensitivity is significantly lower than that by the analysis of MA in exfoliated cells. Conclusion MA was not associated with grade and stage of the bladder cancer. MA assay is a sensitive and effective method for the early detection of bladder cancer and post-operation surveillance.     

RP-HPLC method for the simultaneous determination of daidzein,genistein and formonetin in Solanum Lyratum Thunb

A rapid method for the simultaneous determination of daidzein, genistein and formonetin in solanum Lyratum Thunb by high performance liquid chromatography (HPLC) was developed. Separation was achieved on a Diamonsil C18 column (250 mm×4.6 mm, 5 μm) with isocratic elution, using a mobile phase of methanol-tetrahydrofuran-water (44∶3∶53, v/v). The wavelength was set at 260 nm and column was maintained at 35 ℃. The linear ranges of daidzein, genistein and formonetin were 1.0-40.0, 0.1-4.0 and 0.1-4.0 μg/mL, respectively. The average recoveries were between 98.4% and 101.3%. This method could be used for the quality control of Solanum lyratum Thunb due to its simplification, reliability, rapidity and excellent precision.     

INVESTIGATION ON RELATIONSHIP BETWEEN PREOPERATIONALSENSITIZATION AND CROSSMATCH

Crossmatch has been employed as a mainmethod of donor-recipient matching for manyyears,but it has some disadvantages yet which canbe supplemented by HLA antibody detection. Inthis study,the level of HLA antibody and resu1ts ofcrossmatch were analysed in l67 cases of renaltransplantation.MATERIALS AND METHODS1 MaterlalsOne hundred and sixty seven cases of renaltransplantation, including 1ll males and 56 fe-males, had been performed in our department be-tween Jun. 1998 and Jan. 2000, …     

基于FBG的沥青混合料横向流动变形评价

为了分析沥青混合料横向流动变形, 进行了沥青混合料的车辙试验, 利用布设于沥青混合料板表面的光纤布拉格光栅传感器, 研究了沥青混合料表面的横向应变规律; 以最大应变和蠕变稳定阶段横向应变速率绝对值为评价指标, 分析了沥青混合料横向流动变形。分析结果表明: 横向流动变形随沥青混合料的最大应变和横向应变速率绝对值的减小而降低; 横向流动变形在循环轮载作用下不断发展, 测试点距离轮载愈近其流动变形愈剧烈; 当胶粉掺量分别为0、15%、18%时, 距离轮载63 mm的测试点横向应变速率分别为6.8×10-6、4.0×10-7、6.4×10-6 min-1, 因此, 掺15%胶粉的沥青混合料具有较大的抵抗高温横向流动变形的能力; 对于15%胶粉掺量的沥青混合料, 当其集料级配分别为AC-13粗级配和AC-13细级配时, 距离轮载28 mm的测试点横向应变速率分别为6.0×10-7、7.7×10-6 min-1, 因此, AC-13粗级配沥青混合料高温抗横向流动变形能力优于AC-13细级配; 胶粉改性沥青混合料最大应变为1.96×10-4, 而胶粉和抗车辙剂复合改性沥青混合料最大应变只有1.22×10-4, 说明在高温情况下, 胶粉和抗车辙剂复合改性沥青混合料整体结构强度较大, 能够承受来自轮载的直接作用而不向轮迹两边产生横向推移致使发生较大的横向流动变形。基于光纤布拉格光栅横向应变的沥青混合料横向流动变形评价能较好地说明不同材料和级配对沥青路面产生侧向流动变形规律的影响。      

Construction and evaluation of reference standards for detection and quantification of Klebsiella pneumoniae using real-time PCR

Objective To construct reference standards for detection and quantification of Klebsiella pneumoniae (K.pneumoniae) with SYBR Green I-based real-time PCR assay. Methods Primers were designed based on the published sequence of the phoE gene of K.pneumoniae. The standard was prepared by cell culture, PCR and T-A clone methods, and was identified by colony PCR and DNA sequencing. Results The standard curve showed a very good linear negative regression between threshold cycle (Ct) and Log starting quantity of copy number. The detection range was from 5.2 to 5.2×106 copies per reaction, and the detection limit was 6 copies per reaction. The coefficients of variance (CVs) of three parallel experiments were in the range of 0.05%-0.91%. Conclusion The reference standards have high stability and reproducibility. They can be used in the quantitative detection of K.pneumoniae.     

Electrocatalytic oxidation and determination of dopamine at a carbon ionic liquid electrode modified with nafion-L-aspartic acid composite film

The electrocatalytic oxidation of dopamine (DA) was studied by electrochemical approaches at a carbon ionic liquid electrode (CILE) modified with the composite film of nafion and L-aspartic acid (NL-CILE). The CILE was fabricated by replacing non-conductive organic binders with a room-temperature hydrophobic ionic liquid, 1-butyl-3-methyl-imidazolium hexafluorophosphate. The composite film of NL was used as matrix to adsorb DA and catalyze the oxidation of DA in phosphate buffer solution (PBS). The electrochemical response of DA was investigated at the NL-CILE, the traditional carbon paste electrode (TCPE), CILE and the nafion modified CILE (N-CILE) in 0.1M PBS (pH 7.4), respectively. The results showed the superiority of NL-CILE to N-CILE, CILE and TCPE in terms of provision of higher sensitivity, faster electron transfer and better reversibility. Under optimum condition, the oxidation peak current was rectilinear with DA concentration range from 0.1μM to 0.1mM, with a detection limit of 0.03μM (S/N=3) by differential pulse voltammetry. The proposed method was applied to determine DA in samples successfully.     

Radio Fiber Fine Structure During the Solar Flare on July 14，2000

Introduction　　AmongthefinestructuressuperposedonthecontinuumemissionofsolartypeIVradiobursts,oneofthemostfrequentlyobservedisfiber .Fibers,orintermediatedriftbursts ,werefirstobservedinsolartypeIVcontinuabyYoungetalin 196 1[1] .Thefiberstructuresinmetri…     

流动注射化学发光法测定吩噻嗪类药物

目的确定以鲁米诺-高碘酸钾发光体系测定吩噻嗪类药物的化学发光分析方法。方法在碱性介质中,盐酸氯丙嗪和盐酸异丙嗪对鲁米诺-高碘酸钾发光体系有明显的增敏作用,且增敏效果与其浓度呈良好的线性关系。基于此,建立了盐酸氯丙嗪和盐酸异丙嗪的流动注射化学发光分析方法。结果在优化的实验条件下,盐酸氯丙嗪和盐酸异丙嗪的线性范围分别为3.0×10-9-1.0×10-6g/mL和3.0×10-8-7.0×10-5g/mL,检测限分别为5.0×10-10g/mL和7.3×10-9g/mL。结论本方法简便、快速、准确、灵敏度高、线形范围宽,应用于相应注射剂和片剂分析,并与药典方法进行对照,结果令人满意。     

Detection of captopril based on its enhanced resonance light scattering signals of fluorosurfactant-capped gold nanoparticles

In this study, based on its enhancement effect on resonance light scattering (RLS) of fluorosurfactant (FSN)-capped gold nanoparticles (GNPs), we reported a simple approach for the rapid sensing of captopril. Under optimum conditions, the lowest detectable concentration of captopril through this approach (S/N=3) was 0.01μg/mL. The calibration curve was linear over the range of 0.08-4.0μg/mL for the detection of captopril. The recoveries of captopril were found to fall in the range between 99% and 100%. We have validated the applicability of our method through the analyses of captopril in pharmaceutical formulations. Good agreements were obtained for the determination of captopril between the present approach and official method.