小檗碱-四苯硼钠缔合纳米微粒体系的共振Rayleigh散射光谱及其分析应用小檗碱-四苯硼钠缔合纳米微粒体系的共振Rayleigh散射光谱及其分析应用

目的研究(小檗碱-四苯硼钠)_n缔合纳米微粒的形成与共振Rayleigh散射之间的关系，建立测定小檗碱的共振Rayleigh散射光谱分析新方法。方法采用共振Rayleigh散射光谱法、吸收光谱和透射电镜研究四苯硼钠(TPB)与盐酸小檗碱(BB)的缔合反应。结果在pH 5.0 NaAc-HAc缓冲溶液中，TPB与BB结合形成的(BB-TPB)_n缔合纳米微粒在470 nm处产生一个共振Rayleigh散射（RRS）峰。建立了测定0.06～5.28 mg·L^-1盐酸小檗碱的RRS新方法，检出限为26 μg·L^-1。 结论通过TPB－与BB⁺和Ag⁺反应形成可用透射电镜观测的(BB_jAg_p-TPBj+p)h复合缔合纳米微粒，证实了固液界面的形成是导致其共振Rayleigh散射光增强的充分必要条件。建立的RRS新方法可用于中成药中微量小檗碱的测定，具有灵敏度高，试样用量少等特点。     

A highly sensitive resonance Rayleigh scattering method for the determination of bleomycinA5 and bleomycinA2 with some halofluorescein dyes

In a weak acidic medium, bleomycinA(5) (BLMA(5)) and bleomycinA(2) (BLMA(2)) can react with halofluorescein dyes such as erythrosine (Ery), eosin Y (EY), eosin B (EB) and Rose Bengal (RB) by virtue of electrostatic attraction and hydrophobic force to form ion-association complexes, which can result in the large-scale enhancement of resonance Rayleigh scattering (RRS) and the appearance of new RRS spectra. The increments of scattering intensity (Delta I) were directly proportional to the concentrations of bleomycin (BLM) in certain ranges. The detection limits for BLMA(5) and BLMA(2) ranged from 0.017 to 0.062 microg ml(-1). The Ery system had the highest sensitivity and its detection limit (3sigma) was 0.017 microg ml(-1) for BLMA(5) and 0.018 microg ml(-1) for BLMA(2), respectively. Using Ery as a RRS probe, a new highly sensitive method for the determination of BLM anticancer drugs has been developed. It was applied in the determination of BLMA(5) and BLMA(2) in serum and urine samples. The recovery was from 99.0% to 103.0%. In this work, the RRS spectral characteristics of the binding products and the optimum conditions of the reaction were investigated. The mechanism of ion-association reaction and the reasons of enhancement of resonance light scattering were discussed.     

共振瑞利散射光谱法测定血浆和尿样中的帕珠沙星

目的建立了共振瑞利散射光谱法测定血浆、尿样中帕珠沙星含量的新方法。方法于pH4.8～5.9的Britton-Robinson缓冲溶液中,帕珠沙星与钴(Ⅱ)形成阳离子配合物,其共振瑞利散射(resonance rayleigh scattering,RRS)十分微弱,但当其进一步通过静电引力和疏水作用与刚果红(congo red,CR)阴离子反应形成三元离子缔合物时,RRS出现新的共振瑞利散射光谱,其2个散射峰分别位于380和562nm处。结果在380nm处,帕珠沙星的质量浓度在0.031～3.18μg.mL-1范围内,与RRS强度有良好的线性关系,其检出限(3σ)为24.6ng.mL-1。结论该方法简单、快速,具有良好的选择性和重复性,可用于不同体液中帕珠沙星的测定。     

阿莫西林与甲基紫的共振瑞利散射及应用

目的建立测定痕量阿莫西林的共振瑞利散射法。方法以甲基紫作探针的共振瑞利散射法测定阿莫西林。结果在pH 9.90的Tris-HCl溶液中,阿莫西林和甲基紫相互作用后,共振瑞利散射显著增强,在376 nm处的△IRRS最强。阿莫西林的浓度在2.0×10-8~1.5×10-6 mol.L-1内与△IRRS成正比,检出限（3Sb/S）为0.042μg.mL-1。结论该法简便、快速、灵敏,可用于痕量阿莫西林的测定。     

高灵敏共振瑞利散射技术快速检测药物中的美司那

目的 建立快速、准确测定药物中美司那的高灵敏共振瑞利散射新方法。方法 在BR 弱碱性溶液中,亮绿与美司那以静电作用生成的缔合物使共振瑞利散射(RRS)信号显著增强,RRS 强度在最大共振瑞利散射峰处与美司那的浓度有线性关系。检测波长：344 nm。结果 在pH 7.75 BR缓冲溶液中,亮绿与美司那结合生成绿色二元离子缔合物,产生以294 nm、344 nm 和468 nm 为特征峰的新共振瑞利散射光谱。最大共振瑞利散射峰位于344 nm,线性范围为0.006～0.41 mg/L,检出限为0.0052 mg/L。该法用于市售美司那药物中美司那的测定,加标回收率和相对标准偏差(RSD,n=6)分别为98.3%～103% 和1.6%～2.3%。结论 该法简便、快速,有高灵敏度和高选择性,用于实际药物中美司那的测定,结果满意。     

共振瑞利散射法测定微量唑来膦酸

建立了共振瑞利散射法测定微量唑来膦酸。在酸性条件下,唑来膦酸被破坏后产生的无机磷进一步与钼酸铵结合形成磷钼杂多酸,再与罗丹明B形成磷钼杂多酸-罗丹明B三元离子缔合物后共振瑞利散射急剧增加,并于370nm处有最大散射峰,唑来膦酸在6.25～100ng/ml浓度范围内线性关系良好,检测限为1.55ng/ml。     

茜素共振瑞利散射法测氯霉素的含量

目的建立测定痕量氯霉素的共振瑞利散射法。方法以茜素作探针的共振瑞利散射法测定氯霉素。结果在pH 7.12的Tris-HCl缓冲溶液中,氯霉素和茜素相互作用后,共振瑞利散射显著增强,在373nm处的△IRRS最强。氯霉素的质量浓度在0.097~0.32mg/L范围内与△IRRS成正比,检出限(3Sb/S)为0.080mg/L。结论该法用于氯霉素注射液、滴眼液中氯霉素的测定,结果满意。实现了以廉价试剂、简便方法快速测定痕量药品的目的 。     

共振瑞利散射光谱法测定片剂、人体尿液和血浆中培氟沙星的含量

目的 建立测定片剂、人体尿液和血浆中的培氟沙星含量的共振瑞利散射光谱方法.方法 在pH4.8～5.9 Britton-Robinson缓冲溶液中,培氟沙星(PEFX)可与钴(Ⅱ)反应形成配阳离子,其共振瑞利散射(RRS)十分微弱,但当该配阳离子进一步与酸性染料刚果红(CR)阴离子反应形成三元离子缔合物时,RRS显著增强,3个散射峰别位于278、380和560nm,以380nm为测定波长.结果 线性范围为0.133～3.33μg/mL(r=0.9993),检出限(3σ)为26.4ng/mL.结论 方法简单、快速、并有良好的选择性,可用于片剂、人体尿液和血清中培氟沙星的测定.     

化学发光微粒子免疫法和酶放大免疫法检测环孢素A全血浓度的相关性分析

目的 通过化学发光微粒子免疫法（CMIA）和酶放大免疫法（EMIT）检测环孢素A全血浓度,评价2种方法检测结果的准确性和相关性。方法 CMIA和EMIT检测低、中、高3个全血免疫抑制剂质控物,进行准确度和批内、批间精密度分析;已知浓度的环孢素A（49.5,155.2,395.8,500.0,995.0,1 390.1 ng·mL^-1）加入到不含环孢素A全血样本中,检测后计算结果回收率;测定100份环孢素A患者全血样本,测定值用Deming法进行线性回归分析和Bland-Altman法计算偏倚。结果 CMIA低、中、高3个全血免疫抑制剂质控物准确度相对误差分别为5.8%,5.2%,9.1%,其批内和批间的变异系数分别为7.4%,6.9%,8.6%和10.1%,11.3%,8.7%,CMIA回收率分别为91%,95%,103%,102%,102%,104%;EMIT低、中、高3个全血免疫抑制剂质控物的相对误差分别为2.8%,2.3%,4.3%,其批内和批间的变异系数分别11.2%,5.9%,5.7%和11.3%,9.2%,8.3%,EMIT回收率分别为90%,92%,97%,98%,99%,102%;CMIA和EMIT平均差异偏倚21.7 ng·mL^-1（95% CI：-125.1~168.4 ng·mL^-1）,EMIT测定值/CMIA测定值平均为0.951（95% CI：0.56~1.34）,EMIT测定结果平均低于CMIA 5%左右。结论 CMIA和EMIT检测环孢素A全血浓度符合免疫分析精密度的要求,2种方法的检测结果相关性好,临床合理调整用药剂量时应考虑检测方法类型不同造成的影响。     

Epistatic interaction of CREB1 and KCNJ6 on rumination and negative emotionality

G protein-activated K+ channel 2 (GIRK2) and cAMP-response element binding protein (CREB1) are involved in synaptic plasticity and their genes have been implicated depression and memory processing. Excessive rumination is a core cognitive feature of depression which is also present in remission. High scores on the Ruminative Response Scale (RRS) questionnaire are predictive of relapse and recurrence. Since rumination involves memory, we tested the hypothesis that variation in the genes encoding GIRK2 (KCNJ6) and CREB1 mechanisms would influence RRS scores. GIRK2 and CREB1 polymorphisms were studied in two independent samples (n = 651 and n = 1174) from the general population. Strongly significant interaction between the TT genotype of rs2070995 (located in KCNJ6) and the GG genotype of rs2253206 (located in CREB1) on RRS were found in both samples. These results were validated in an independent third sample (n = 565; individuals with personality disorders) showing significant main effect of the variants mentioned as well as significant interaction on a categorical diagnosis of Cluster C personality disorder (obsessional-compulsive, avoidant and dependent) in which rumination is a prominent feature. Our results suggest that genetic epistasis in post-receptor signaling pathways in memory systems may have relevance for depression and its treatment.     

Osteryoung square wave stripping voltammetry at mercury film electrode for monitoring ultra trace levels of Tarabine PFS and its interaction with ssDNA

The electrochemical oxidation and reduction behaviour of adsorbed species of antimetabolic antineoplastic agent Tarabine PFS (Cytosar-U) in Sorensen buffer solution of different pH values at an in situ-mercury film electrode (MFE) is studied using cyclic voltammetry (CV) and Osteryoung square-wave stripping voltammetry (OSWSV). Optimal experimental and operational parameters have been selected for the drug preconcentration and determination in aqueous medium. Based on the adsorption and accumulation of Tarabine PFS using Osteryoung square-wave anodic stripping voltammetry (OSWASV) at MFE, the drug is easily detected as 0.134 ng/ml (5.51×10⁻¹⁰ M). Calibration plots have been constructed at different accumulation times. The standard deviation (n=10) at a concentration level of 6×10⁻⁸ M Tarabine PFS is 0.062. The interaction of ssDNA with the drug under the optimal conditions at pH 7.7 has been studied. The formal potentials E° and E°^′ and the equilibrium constants K₁ and K₂ have been calculated for the free form of Tarabine PFS and the bonded form with ssDNA, respectively. It was found that K₂ value for the bonded oxidized form is 298 times than that of K₁ for the bonded reduced form. Therefore, ssDNA has been found to interact strongly with the oxidized form of the drug. The method has been used for the nanogram determination of ssDNA with 1.9% variation coefficient. Detection limit of 3 ng/ml ssDNA has been achieved. Possible interfering organic compounds, cations and anions have been tested. The method has been applied for the drug determination in urine samples, down to 0.23 ng/ml could be easily achieved in such samples.     

Determination of bismuth in pharmaceutical products using methyltriphenylphosphonium bromide as a molecular probe by resonance light scattering technique

A method for the determination of bismuth in pharmaceutical products using methyltriphenylphosphonium bromide as a molecular probe based on the resonance light scattering (RLS) technique was developed. In the presence of Tween-20, bismuth reacts with a large excess of I(-) to form [BiI(4)](-), which further reacts with methyltriphenylphosphonium bromide (MTPB) to form an ion-association compound. This resulted in a significant enhancement of RLS intensity and the appearance of the corresponding RLS spectral characteristics. The enhanced RLS intensity was directly proportional to the concentration of Bi(III) in the range of 0.001-1.50 microg/ml for the system. The detection limit was 0.98 ng/ml. The characteristics of RLS spectra of the complex, the optimum conditions and the influencing factors were investigated. The method has high selectivity and was applied to the determination of Bi(III) in pharmaceutical products with satisfactory results, which were in agreement with those of the official method and atomic absorbance spectrometry (AAS).     

Electroanalytical study of the antidepressant sertraline

A flow injection square wave cathodic stripping voltammetric method has been developed for the determination of sertraline in a pharmaceutical preparation. The method shows linearity between peak current intensity and sertraline concentration for the interval between 0.20 x 10(-6) and 1.20 x 10(-6) mol L(-1). Limits of detection and quantification were found to be 1.5 x 10(-7) and 5.0 x 10 (-7) mol L(-1), respectively. Up to 70 samples per hour can be analysed with a good precision (R.S.D. = 2.5%). The proposed method was successfully applied to the determination of sertraline in a commercial product. In the voltammetric determination of sertraline in flow, a high sample rate is obtained at reduced costs, opening the possibility to compete with the chromatographic methods generally used for this analysis.     

Square wave adsorptive stripping voltammetric determination of piromidic acid. Application in urine

A simple procedure for the determination of piromidic acid by square wave adsorptive stripping voltammetry (SW-AdSV) at a hanging mercury drop electrode has been developed. The variables affecting to accumulation process such as concentration of perchloric acid, accumulation potential and accumulation time have been optimised (0.025 mol L(-1), -0.25 V and 140 s, respectively) by using response surface methodology. A linear relationship between concentration of piromidic acid and peak intensity has been found in the range 2.22 x 10(-9) to 3.33 x 10(-8) mol L(-1). The detection limit (1.65 x 10(-9) mol L(-1)) has been calculated by the method proposed by Clayton et al. so that protection against both false positive and false negative errors is assured. The procedure was successfully applied to determine piromidic acid in spiked urine samples. The obtained recovery values were in the range 97.3-103.3% at different levels of concentration of piromidic acid.     

Fluorescence spectroscopy determination of fluoroquinolones by charge-transfer reaction

The charge-transfer (CT) reaction between chloranilic acid (CL) as a pi-electron acceptor and lomefloxacin (LOM), fleroxacin (FLX), ciprofloxacin (CPFX), norfloxacin (NOR) as electron donor have been studied by fluorimetry. The CT complexes have stable purple color in acetone solution and the fluorescence intensity of the CT complexes was enhanced in 4-14 fold higher than that of the four fluoroquinolones (FQS) itself, therefore a new spectrofluorimetric method with simple, rapid, accurate, high sensitivity and good selectivity for determination of the four FQS has been developed. The method was applied for determination of drugs (LOM, FLX, CPFX and NOR) in tablets with mean percentage accuracies 99.80+/-1.12, 99.93+/-0.92, 99.23+/-1.36 and 99.87+/-0.81, respectively.     

Determination of sparfloxacin in plasma and urine by a simple and rapid liquid chromatographic method.

A simple, specific, sensitive, and rapid method has been developed and validated for the determination of sparfloxacin in human plasma and urine. The assay consisted of reversed-phase HPLC with ultraviolet detection. Plasma proteins were efficiently removed by precipitation with perchloric acid after the addition of grepafloxacin as an internal standard. For the urine samples, the only required sample preparation was dilution. Separation was achieved on a C18 reversed-phase column. The quantification limit was 0.025 mg/L in plasma and 0.5 mg/L in urine. The coefficients of variation (CV) were less than 10% for intra-day and inter-day analyses. The recovery of sparfloxacin added to plasma and urine ranged from 96.7% to 97.9%. The method has been successfully applied to pharmacokinetic studies.     

A new HPLC/UV method for the determination of clindamycin in dog blood serum

A new HPLC method for the quantitative determination of clindamycin in dog blood serum at levels down to 80 ng/ml has been developed. Samples were deproteinised with acetonitrile and clindamycin was extracted with dichloromethane. Chromatographic analysis was carried out on a C(18) reversed-phase analytical column in the presence of tetra-n-butylammonium hydrogen sulfate (TBA), as an ion-pairing agent. UV detector wavelength was set at 195 nm. The assay was validated for a concentration range from 80 to 6000 ng/ml serum. Good linearity was observed in the entire concentration range. The limit of quantification (LOQ) was 80 ng/ml and the limit of detection (LOD) was 60 ng/ml. Regression of accuracy data yielded an overall mean recovery value (+/-S.E.M.) of 93.98+/-0.42%, while precision data revealed coefficient of variation (CV (%)) values lower than 4.41%. The method was successfully applied to determine drug concentrations in serum samples from dogs that had been orally administered clindamycin hydrochloride.     

Improvements in europium sensitized fluorimetric determination of demeclocycline and methacycline

Demeclocycline (DM) and methacycline (MT) have been determined by europium-sensitized fluorescence, using EDTA as co-ligand and cetyltrimethylammonium chloride as surfactant. The methods have been developed in slightly alkaline solutions, with the formation of a new chelate where the lanthanide ion is bound to the beta-diketone group. Calibration graphs between 0.01 and 0.1 μg mL⁻¹ have been obtained for DM and MT determination. Both methods have been applied to the determination of these tetracyclines in serum samples with satisfactory recovery results.     

Voltammetric quantification of tamoxifen

The electrochemical behaviour of tamoxifen has been investigated at gold electrode by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and squarewave voltammetric techniques. The dependence of current and potential on pH, concentration, scan rate, nature of solvent, surfactants and different surfactant concentration is investigated. Tamoxifen is oxidized in a single two-electron, irreversible and diffusion-controlled wave. Linear calibration plots are obtained over the concentration range 1.0-5.0 and 1.0-6.0 μgmL(-1) in 1.0 M KCl and Britton Robinson buffers (pH 2.51) respectively. The procedure has been applied to the assay of the drug in tablet form with mean percentage recoveries of 99.98%. The suggested method can be successfully applied to the determination of tamoxifen in different drug formulations.     

Determination of carvedilol by its quenching effect on the luminescence of terbium complex in dosage form

A new, simple, sensitive luminescence methods for the determination of carvedilol have been developed and validated. Carvedilol was remarkably quenching the luminescence intensity of the Tb(III) ion in the new terbium complex with 1-butyl-4-hydroxy-2-oxo-1,2-dihydroquinoline-3-carboxylic acid-(4-methyl-pyridin-2-yl)-amide (R) in aqueous solutions containing urotropine buffer (pH 7.5) at lambda(ex) = 317 nm and lambda(em) = 545 nm. Under optimal conditions, the quenching of luminescence intensity was found to be proportional to the concentration of carvedilol in the range of 0.5-400 microg/mL. The detection limit was 0.16 microg/mL. This method was applied for the determination of carvedilol in tablets "Coryol".