Sensitive assay for catecholamines in pharmaceutical samples and blood plasma using flow injection chemiluminescence analysis.

A rapid and sensitive chemiluminescence (CL) method using flow injection analysis was described for the determination of three catecholamines: dopamine, adrenaline and dobutamine, based on their greatly enhancing effects on the CL reaction of luminol-potassium periodate in basic solutions. Under the optimized conditions, the calibration graphs relating the increase of CL intensity to the concentration of the analytes were linear. The present method allows for the determination of dopamine, adrenaline, and dobutamine over the range of 1.0 x 10(-10) - 1.0 x 10(-7) g/ml. The relative standard deviations for measurements (n=11) of dopamine, adrenaline and dobutamine were 2.9, 2.3 and 1.8% when the concentrations of three catecholamines were at 1.0 x 10(-9) g/ml, respectively. The detection limits of the method were 2.0 x 10(-11) g/ml dopamine, 1.0 x 10(-11) g/ml adrenaline and 4.0 x 10(-11) g/ml dobutamine. The method was successfully applied to the determination of three catecholamines in pharmaceutical samples and blood plasma.     

Post-chemiluminescence phenomenon of NBS-luminol reactions and their applications to flow injection analysis of piroxicam.

A new post-chemiluminescence (PCL) reaction was observed when piroxicam was injected into the reaction mixture after the CL reaction of N-bromosuccinimide (NBS) and luminol. A possible reaction mechanism was proposed based on the studies of the CL kinetic characteristics, the CL spectra, fluorescence spectra and other experiments. A new flow injection CL method for the determination of piroxicam was established based on the PCL reaction. The relative standard deviation (RSD) for the determination of piroxicam was 1.2% (n = 11, c = 2.0 x 10(-6) g/ml). The CL intensity responded linearly to the concentration of piroxicam in the range 1.0 x 10(-7) - 1.0 x 10(-5) g/ml (r = 0.9991). The detection limit was 4.0 x 10(-8) g/ml. The method had been applied to the determination of piroxicam in tablets with satisfactory results.     

Flow-injection chemiluminescence sensor for determination of isoniazid in urine sample based on molecularly imprinted polymer

In this paper, molecularly imprinted polymer (MIP) of isoniazid is synthesized through thermal radical copolymerization of metharylic acid (MAA) and ethylene glycol dimethacrylate (EGDMA) in the presence of isoniazid template molecules. A novel flow injection chemiluminescence sensor for isoniazid determination is developed by packing the isoniazid-MIP into the flow cell as recognition elements. Isoniazid could be selectively adsorbed by the MIPs and the adsorbed isoniazid was sensed by its great enhancing effect on the weak CL reaction between luminol and periodate which were mixed in the flow cell. The enhanced CL intensity is linear in the range 2x10(-9) to 2x10(-7) g/mL and the detection limit is 7x10(-10) g/mL (3sigma) isoniazid with a relative standard deviation 2.8% (n=9) for 8x10(-8) g/mL. The sensor is reversible and reusable. It has a great improvement in sensitivity and selectivity for CL analysis. As a result, the sensor has been successfully applied to determination of isoniazid in human urine. At the same time, the binding characteristic of the polymer to isoniazid was evaluated by batch method and the dynamic method, respectively.     

Flow-injection chemiluminescence determination of ofloxacin and levofloxacin in pharmaceutical preparations and biological fluids.

A novel, rapid and sensitive analytical method is described for determination of ofloxacin and levofloxacin by enhanced chemiluminescence (CL) with flow-injection sampling. The method is based on the CL reaction of the Ce(IV)-Na2S2O4-ofloxacin/levofloxacin-H2SO2 system. The enhanced CL mechanism was developed and the optimum conditions for CL emission were investigated. The CL intensity was correlated linearly (r = 0.9988) with the concentration of ofloxacin (or levofloxacin) in the range of 1.0 x 10(-8) - 1.0 x 10(-7) g ml(-1) and 1.0 x 10(-7) - 6.0 x 10(-6) g ml(-1). The detection limit (S/N = 3) is 7 x 10(-9) g ml(-1). The relative standard derivation (RSD, n = 11) is 2.0% for ofloxacin at 4 x 10(-7) g ml(-1) and for levofloxacin at 6 x 10(-7) g ml(-1). This method has been successfully applied for the determination of ofloxacin and levofloxacin in pharmaceutical preparations and biological fluids with satisfactory results.     

Investigating the post-chemiluminescence behavior of phenothiazine medications in the luminol–potassium ferricyanide system: molecular imprinting–post-chemiluminescence method for the determination of chlorpromazine hydrochloride

A new post-chemiluminescence (PCL) phenomenon was observed when phenothiazine medications were injected into the reaction mixture after the chemiluminescence (CL) reaction of luminol and potassium ferricyanide had finished. A possible reaction mechanism was proposed based on studies of the kinetic characteristics of the CL, CL spectra, fluorescence spectra, and on other experiments. The feasibility of determining various phenothiazine medications by utilizing these PCL reactions was examined. A molecular imprinting–post-chemiluminescence (MI-PCL) method was established for the determination of chlorpromazine hydrochloride using a chlorpromazine hydrochloride-imprinted polymer (MIP) as the recognition material. The method displayed high selectivity and high sensitivity. The linear range of the method was 1.0×10⁻⁸∼1.0×10⁻⁶, with a linear correlation coefficient of 0.9985. The detection limit was 3×10⁻⁹ g/ml chlorpromazine hydrochloride, and the relative standard deviation for a 1.0×10⁻⁷ g/ml chlorpromazine hydrochloride solution was 4.0% (n=11). The method has been applied to the determination of chlorpromazine hydrochloride in urine and animal drinking water with satisfactory results.      

铁氰化钾-鲁米诺体系后化学发光反应及其分析应用研究-分子印迹-后化学发光法测定双嘧达莫

研究了双嘧达莫在铁氰化钾-鲁米诺化学发光反应体系中的后化学发光反应, 并在研究其反应的动力学性质、化学发光光谱、荧光光谱以及一些相关问题的基础上, 探讨了反应机理; 合成了双嘧达莫的分子印迹聚合物, 以此聚合物为分子识别物质, 利用铁氰化钾-鲁米诺-双嘧达莫后化学发光体系, 建立了测定双嘧达莫的高选择性分子印迹-后化学发光分析方法. 所建方法的线性范围为1.0×10-8-1.0×10-6 g/mL(r=0.999 2), 检出限为3×10-9 g/mL, 相对标准偏差为2.7%(1.0×10-7 g/mL双嘧达莫, n=11).     

Molecular imprinting-chemiluminescence determination of trimethoprim using trimethoprim-imprinted polymer as recognition material

A new molecular imprinting-chemiluminescence method for the determination of trimethoprim was developed, in which trimethoprim-imprinted polymer was used as the molecular recognition material and the CL reaction of trimethoprim with potassium permanganate in acidic medium was used as the detection system. The CL intensity responds linearly to the concentration of trimethoprim within the 5.0 x 10(-8)-5.0 x 10(-6) g mL(-1) range (r= 0.9983) with a detection limit of 2 x 10(-8) g mL(-1). The relative standard deviation for the determination of 1.0 x 10(-7) g mL(-1) trimethoprim solutions is 4.8% (n= 9). The method has been applied to the determination of trimethoprim in pharmaceutical preparations and body fluids, and satisfactory results were obtained.     

流动注射化学发光法测定头孢他啶

在碱性条件下,头孢他啶对金纳米粒子催化高锰酸钾氧化鲁米诺化学发光体系的发光强度具有明显的增敏作用,基于此建立了一种测定头孢他啶的化学发光方法.在优化实验条件下,用该法测定头孢他啶的线性范围为3.0×10-5～5.0×10-2 g/L,检出限为1.0×10-5 g/L,相对标准偏差为2.0%(ρ=4.0×10-3 g/L...     

Determination of riboflavin by enhancing the chemiluminescence intensity of peroxomonosulfate-cobalt(II) system

A weak chemiluminescent (CL) emission was observed in the decomposition of peroxomonosulfate (HSO5-), which would be accelerated in the presence of trace amounts of cobalt (II). The mechanism was due to the production of singlet oxygen (1O2). Interestedly, riboflavin can enhance the CL and the CL intensity was strongly dependent on riboflavin concentration. Based on this phenomenon, a flow injection analysis (FIA) CL method was established for the determination of riboflavin. Additionally, the possible CL mechanism is proposed based on the kinetic curve of the CL reaction, CL spectra, UV-vis spectra and fluorescent spectra. The CL intensity was correlated linearly with concentration of riboflavin over the range of 1.0x10(-4) to 1.0x10(-8) g mL-1; the detection limit was 9.0x10(-9) g mL-1(S/N=3); the relative standard deviation was 1.4% for 9x10(-7) g mL-1 riboflavin (n=11). Furthermore, this method was applied to the determination of riboflavin in real tablets and injections successfully.     

氯丙嗪分子印迹敏感膜传感器的制备与应用

以氯丙嗪为模板分子,邻氨基酚为功能单体,在金电极表面电聚合制备具有特异性识别孔穴的氯丙嗪分子印迹敏感膜(MIP)。 采用循环伏安法(CV)、差分脉冲伏安法(DPV)等研究了印迹膜的性能、结构和分子印迹效应,并与其结构相似的化合物奋乃静和异丙嗪的选择性响应进行了比较,发现传感器对氯丙嗪具有良好的选择性。 氯丙嗪浓度在6.0×10-7～9.0×10-5 mol/L范围内与峰电流呈线性关系,线性方程为:I(μA)=61.25lg c(μmol/L)+23.47(r=0.9975),根据DL=3δb/s计算检出限为2.0×10-7 mol/L,该传感器具有良好的重复性、再生性和高灵敏度。     

Determination of catecholamines by CE with direct chemiluminescence detection

A rapid and sensitive method to detect three catecholamines, isoprenaline, epinephrine, and dopamine, by CE coupled with direct luminol-potassium periodate chemiluminescence (CL) detection is described. The conditions for CE separation and CL reaction were systematically optimized. Under the optimum conditions, the baseline separation of three catecholamines was achieved within 6.5 min. The LODs obtained in standard solution were 5.3 x 10(-8 )mol/L for isoprenaline, 4.7 x 10(-8 )mol/L for epinephrine, and 1.5 x 10(-7 )mol/L for dopamine. The RSD of the migration time and peak area were less than 1.8 and 3.6% (n = 5), respectively. The present method was applied to the determination of the dopamine in urine samples of cigarette smokers and nonsmokers. The results obtained indicate that there is a close relationship between the content of dopamine in human urine and the amount of cigarettes smoked daily; the level of dopamine in smokers is higher than in nonsmokers.     

Sensitive determination of phenothiazines in pharmaceutical preparation and biological fluid by flow injection chemiluminescence method using luminol-KMnO4 system

A flow injection chemiluminescence method was described for the determination of four phenothiazine drugs, namely, chlorpromazine hydrochloride, perphenazine hydrochloride, fluphenazine hydrochloride and thioridazine hydrochloride. Strong Chemiluminescence (CL) signal was produced when above-mentioned drug was injected into the mixed stream of luminol with KMnO₄. The linear ranges of the method were 0.0020-1.0 μg/mL chlorpromazine hydrochloride, 0.0040-3.0 μg/mL perphenazine hydrochloride, 0.0020-5.0 μg/mL fluphenazine hydrochloride and 0.0050-1.0 μg/mL thioridazine hydrochloride. The detection limits were 0.4 ng/mL chlorpromazine hydrochloride, 0.7 ng/mL perphenazine hydrochloride, 2 ng/mL fluphenazine hydrochloride and 0.7 ng/mL thioridazine hydrochloride. The proposed method was applied to the determination of chlorpromazine hydrochloride in injections and in mental patient's urine samples and the satisfactory results were achieved. The possible CL reaction mechanism was also discussed briefly.     

A study of a new TSM bio-mimetic sensor using a molecularly imprinted polymer coating and its application for the determination of nicotine in human serum and urine

A new bio-mimetic quartz crystal thickness-shear-mode (TSM) sensor, using an imprinted polymer coating as the sensitive material, has been fabricated and applied to the determination of nicotine (NIC) in human serum and urine. The molecularly imprinted polymer (MIP) was synthesized using NIC as the template molecule and methacrylic acid (MAA) as the functional monomer. The sensor showed high selectivity and a sensitive response to NIC in aqueous system. The linear response range of the sensor was between 5.0 x 10(-8) and 1.0 x 10(-4) M with a detection limit of 2.5 x 10(-8) M. The viscoelasticity of the coating in the air and in liquid has been studied by the impedance spectrum. The MIP sensor was stable and exhibited effective reproducibility. Satisfactory results were achieved in the detection of the real samples.     

Chemometrics-assisted simultaneous determination of cobalt(II) and chromium(III) with flow-injection chemiluminescence method

In this paper, a flow-injection chemiluminescence (CL) system is proposed for simultaneous determination of Co(II) and Cr(III) with partial least squares calibration. This method is based on the fact that both Co(II) and Cr(III) catalyze the luminol-H(2)O(2) CL reaction, and that their catalytic activities are significantly different on the same reaction condition. The CL intensity of Co(II) and Cr(III) was measured and recorded at different pH of reaction medium, and the obtained data were processed by the chemometric approach of partial least squares. The experimental calibration set was composed with nine sample solutions using orthogonal calibration design for two component mixtures. The calibration curve was linear over the concentration range of 2 x 10(-7) to 8 x 10(-10) and 2 x 10(-6) to 4 x 10(-9) g/ml for Co(II) and Cr(III), respectively. The proposed method offers the potential advantages of high sensitivity, simplicity and rapidity for Co(II) and Cr(III) determination, and was successfully applied to the simultaneous determination of both analytes in real water sample.     

Flow injection with inhibited chemiluminescence method for the determination of dopamine hydrochloride.

A simple rapid and accurate flow injection inhibitory chemiluminescence method has been developed for the determination of dopamine hydrochloride based on its inhibition of the chemiluminescence from the luminol-potassium hexacyanoferrate(III) system. The linear range of determination is 4.0 x 10(-9) - 4.0 x 10(-7) g ml(-1) for dopamine hydrochloride and the detection limit is 1.14 x 10(-9) g ml(-1). The method has been applied to determine the content of dopamine in pharmaceutical preparation with satisfactory results.     

分子印迹化学发光传感器在线检测牛肉与鸡肉组织中残留的磺胺嘧啶

以分子印迹作为识别体,制成高灵敏度和高选择性的化学发光传感器在线检测牛肉与鸡肉组织中残留的磺胺嘧啶。磺胺嘧啶作为靶分子,通过悬浮聚合制备了1～10μm的分子印迹聚合物。将分子印迹聚合物装入聚四氟乙烯管中,作为固相萃取柱,并联在八通阀上,用于在线选择吸附磺胺嘧啶。在最佳条件下,测得磺胺嘧啶线性范围7.0×10–9～9.0×10–7g/mL,方法的检出限为(3σ)2×10–10g/mL,11次平行测定3.0×10–8g/mL的磺胺嘧啶溶液的化学发光强度相对标准偏差为3.4%。方法能够用于检测肉类产品中残留的磺胺嘧啶。     

Luminol-K_3[Fe(CN)_6]流动注射化学发光体系检测头孢吡肟

在碱性介质中,头孢吡肟对Luminol-K3[Fe(CN)6]化学发光体系具有明显的增强作用,基于此建立了流动注射化学发光法测定头孢吡肟的新方法。在优化实验条件下,化学发光增强强度与头孢吡肟的浓度在3.0×10-6~4.0×10-5g/m L范围内呈良好的线性关系,检出限为2.8×10-6g/m L。对2.0×10-5g/m L头孢吡肟平行测定11次,相对标准偏差(RSD)为1.5%。该方法用于头孢吡肟针剂的测定,结果满意。     

Study of a molecular imprinting polymer coated BAW bio-mimic sensor and its application to the determination of caffeine in human serum and urine

A bio-mimic bulk acoustic wave (BAW) sensor was fabricated by coating the caffeine (CAF) template molecular imprinting polymer (MIP). This sensor exhibited high selectivity and a sensitive mass response to CAF. The response range of the sensor was between 5.0 x 10(-9) and 1.0 x 10(-4) M with a detection limit of 5.0 x 10(-9) M at pH 8.0. Recoveries were 96.1-105.6%. Influencing factors were investigated in detail and optimized. When employed to detect real samples, the proposed method proved to be a convenient method with the advantages of high sensitivity, good selectivity and ease of handling.     

Molecularly imprinted on-line solid-phase extraction combined with flow-injection chemiluminescence for the determination of tetracycline

A molecularly imprinted polymer solid phase extraction (MISPE) method combined with flow-injection chemiluminescence (FI-CL) for the determination of residual tetracycline (TC) in fish samples is presented. The molecularly imprinted polymer (MIP) of TC was synthesized and particles of this MIP were packed into a polytetrafluoroethylene (PTFE) tube, which was connected into the sampling loop of an eight-way injection valve and served as the MISPE column for on-line selective adsorption of TC. The eluent (CH3CN : HNO3 (0.01 mol L(-1)) = 4 ratio 1, v ratio v) was used for extracting the adsorbed TC, which could be detected by its good enhancing effect on the CL reaction between Ce(iv) and rhodamine B. The CL intensity is linear to TC concentration in the range from 4 x 10(-9) to 4 x 10(-7) g mL(-1). The detection limit is 1 x 10(-9) g mL(-1) (3 sigma) and the relative standard deviation is 2.4% (n = 9). The conditions of preconcentration, extraction and CL reaction were carefully studied. The selectivity experiment shows that the selectivity and sensitivity of the CL method could be improved greatly when MIP was used as a recognition material in SPE. However, the MISPE column interacted indiscriminately with oxytetracycline (OTC) with a 49 +/- 2% binding. An intermediate differential pulsed elution (DPE) step using 3% acetic acid as eluent was employed to remove OTC and other interfering substances. The proposed MISPE-CL method has been applied successfully to the determination of TC in fish samples. At the same time, the binding characteristics of the polymer to tetracycline were evaluated by batch and dynamic methods.     

Determination of trace aluminum (III) using a novel cerium (IV)-calcein chemiluminescence detection

A simple, sensitive and selective chemiluminescence (CL) method was developed for the direct determination of aluminum (Al). This method is based on that the weak CL of cerium (IV)-calcein can be greatly enhanced by Al(III). The calibration curve was linear over the range 2.0 x 10(-10) to 4.0 x 10(-8)g mL(-1) with a detection limit of 8 x 10(-11)g mL(-1) (3sigma). The R.S.D. was 2.5% by 11 replicated determinations of 1.0 x 10(-9)g mL(-1) Al(III). The proposed method has been used to determine the concentration of Al(III) in real water samples with satisfactory results. The mechanism of the CL reaction was also discussed.