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In this work, a new molecularly imprinted polymer (MIP) based lab-on-paper device with chemiluminescence (CL) detection of dichlorvos (DDV) was designed. With the circle-shaped device, the MIP layer with certain depth was synthesized and adsorbed on the paper surface and DDV can be selectively imprinted on it. The adsorption and washing procedures can be achieved well on the paper-based chip. The paper-based device was fabricated by a simple cutting method and many chips can be made at the same time. On the basis of DDV enhancing CL of luminol-H2O2 greatly, the proposed MIP based lab-on-paper CL device showed better selectivity to DDV and it has been applied to the determination of DDV in vegetables in the range of 3.0 ng/mL-1.0 μg/mL with the detection limit of 0.8 ng/mL. This study has made a successful attempt in the development of highly selective and sensitive monitoring of DDV in real samples and will provide a new approach for sensitive and specific assay in environmental monitoring., (Copyright © 2015 Elsevier B.V. All rights reserved.)

A laminated paper-based analytical device (LPAD) combined with gold nanoparticles (AuNPs) catalyzed luminol chemiluminescence (CL) system for the determination of L-cysteine (L-cys) was presented here. It is based on the principle that L-cys can greatly inhibit CL signal of AuNPs-luminol-H2O2 system. The paper-based device was fabricated by a low-cost cutting method, followed by lamination with two polyester films. This approach of cutting/lamination to fabricate LPAD is very similar to making a lamination picture. A good linear relationship was obtained between the CL intensity and the concentrations of L-cys in the range from 1.0×10(-8) M to 1.0×10(-6) M with a detection limit at 8.2×10(-10) M (S/N=3). This study shows the successful integration of the LPAD and the CL method. It will be of interest for use in areas such as disease diagnosis in the future., (Copyright © 2013 Elsevier B.V. All rights reserved.)

A novel chemiluminescence (CL) system with diperiodatonickelate (IV) (DPN) was developed for the determination of adrenaline for the first time. The possible CL emission mechanism was briefly discussed by comparing the fluorescence emission spectra with CL spectra. Under the optimum conditions, the relative CL intensity was linear over the concentration of AD ranging from 1.0×10(-7) to 1.0×10(-5) g mL(-1) with a detection limit of 4.0×10(-8) g mL(-1) (3σ). And the relative standard deviation was 3.7% for 2.0×10(-6) g mL(-1) AD (n=11). The developed method has been successfully applied to the determination of AD in pharmaceutical preparations., (Copyright © 2013 Elsevier B.V. All rights reserved.)

A new chemiluminescent (CL) probe array assay approach was first developed. The new CL probe array was based on Co3O4-SiO2 mesoporous nanocomposite material, which not only has an excellent catalytic effect on the luminol-H2O2 CL reaction in alkaline medium but also can be used for the immobilization of enzymes. As a model, the novel bifunctional CL probe array has been applied to the high-throughput determination of glucose in human. The linear range of the glucose concentration was 3-90 μM and the detection limit was 0.36 μM. It breaks traditional development view in solid phase supports and provides new insights into the application of mesoporous material., (Copyright © 2013 Elsevier B.V. All rights reserved.)

In this work, an electrogenerated chemiluminescence (ECL) detector with improved stability was developed for high-performance liquid chromatography (HPLC) detection of hydrochlorothiazide (HCTZ). The detector was prepared by packing cation exchanged resin particles in a glass tube, followed by inserting Pt wires (working electrode) in this tube and sealing. The leakage of Ru(bpy)3(2+) from the resin was compensated by adding a small amount of Ru(bpy)3(2+) in the mobile phase. Factors affected the performance of the proposed ECL detector were investigated. Under the optimal conditions, the ECL intensity has a linear relationship with the concentration of HCTZ in the range of 5.0 × 10(-8) g mL(-1)-2.5 × 10(-5) g mL(-1) and the detection limit was 2.0 × 10(-8) g mL(-1) (S/N=3). Application of the detector to the analysis of HCTZ in human serum proved feasible., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Toll-like receptors (TLRs) are important initiators in innate immune responses against pathogenic microbes such as viruses, intracellular bacteria or parasites. Although the innate immune system is designed to fight infectious pathogens, excessive activation of TLR signaling may lead to unwarranted inflammation with hazardous outcomes. Mechanisms of restraining excessive inflammation and controlling homeostasis for innate immunity are the focus of intense study. Here we showed that LRRC33, a novel member of leucine-rich repeat (LRR) protein family, plays a critical role in desensitizing TLR signaling. LRRC33 is TLR homolog that contains 17 putative LRRs in the extracellular region but lacks a cytoplasmic Toll/IL-1 receptor (TIR) domain. Expression of LRRC33 appears to be ubiquitous with high level of expression found in bone marrow, thymus, liver, lung, intestine and spleen. The LRRs of LRRC33 is required for the interaction with TLR and its inhibitory effect on NF-κB and AP-1 activation as well as cytokine production. Our study sheds new insight into the TLR signaling and inflammatory response in development and human diseases., (Copyright © 2013 Elsevier Inc. All rights reserved.)

The catalytic properties of cubiform Co3O4 nanoparticles, α-Fe2O3 nanorods, and NiO nanoparticles were studied using both microarray method and FI-CL method. These nanoarticles exhibit high specific catalytic effects on the chemiluminescence (CL) reaction of the luminol-H2O2 system in alkaline solution compared with other common catalysts. A reaction mechanism is described. It provides new insights into the application of nanoparticle materials. The CL method based on the use of the Co3O4 nanoparticles is ultrasensitive and particularly selective. Therefore, it was applied to the analysis of H2O2 which can be determined in the concentration range from 1.0 nM to 1000 nM, with a detection limit of 0.3 nM. The relative standard deviation is 2.1% at 0.1 μM of H2O2 (for n=11). The method was successfully applied to the determination of trace quantities of H2O2 in exhaled breath condensate (EBC) where it is a mediator of oxidative stress and a promising biomarker for diagnosing. The assay requires a small sample and no incubation time, and has an analytical runtime of <1 min. It is timesaving and suitable for larger studies. The levels of H2O2 in EBC are found to be elevated in healthy subjects (average=0.54 nM), rheum subjects (average=0.24 nM), and feverish subjects (average=0.16 nM). Our data suggested that the average H2O2 concentration of EBC from feverish subjects was significantly higher than healthy subjects and rheumatic subjects., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Captopril exhibit electrogenerated chemiluminescence (ECL) in NaNO(3) solution when constant current is exerted. Based on this observation, a direct ECL method coupled with high-performance liquid chromatography (HPLC) separation is developed for determination of captopril in human serum. Factors affected the ECL emission are investigated. Under the optimal conditions, the ECL intensity has a linear relationship with the concentration of captopril in the range of 4.0×10(-6)-2.0×10(-3) g mL(-1) and the detection limit is 2×10(-6) g mL(-1) (S/N=3). Compared with the common electrogenerated chemiluminescence experiments, the developed method need no any other fluorescence additives., (Copyright © 2012 Elsevier B.V. All rights reserved.)

A new kind of ultrabright fluorescent and chemiluminescent difunctional mesoporous silica nanoparticle (FCMSN) is reported. A luminescent dye, Rhodamine 6G or tris(2,2'-bipyridyl)dichlororuthenium(II) hexahydrate (Rubpy), is doped inside nanochannels of a silica matrix. The hydrophobic groups in the silica matrix avoid the leakage of dye from open channels. The amines groups on the surface of the FCMSN improve the modification performance of the nanoparticle. Because the nanochannels are isolated by a network skeleton of silica, fluorescence quenching based on the inner filter effect of the fluorescent dyes immobilized in nanochannels is weakened effectively. The Quantum Yield of obtained 90 nm silica particles was about 61%. Compared with the fluorescent core-shell nanoparticle, the chemiluminescence reagents can freely enter the nanoparticles to react with fluorescent dyes to create chemiluminescence. The results show that the FCMSN are both fluorescent labels and chemiluminescent labels. In biological applications, the NaIO(4) oxidation method was proven to be superior to the glutaraldehyde method. The amount of amino could affect the specificity of the FCMSN. The fluorescence microscopy imaging demonstrated that the FCMSN is viable for biological applications., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Staphylococcal enterotoxin B (SEB) is a potent gastrointestinal toxin and is heat resistant. SEB is also a potential bioterrorism agent. The ability to measure accurately very low amounts of staphylococcal enterotoxin B in food and other samples is very important. A highly sensitive and stable sandwich fluorescence immunoassay based on a pair of monoclonal antibodies against SEB which were produced by us was developed. Classical sandwich immunoassay was adopted and the glass slides were used as the base of the immunologic reaction. The functionalized fluorescent core-shell silica nanoparticles were used as labels. The fluorescence issued from the labels was detected by a laser-induced fluorescence millimeter sensor array detection platform. The fluorescence intensity has a linear relationship with the amount of SEB in the range of 50 pg/mL-5 ng/mL, and the detection limit of SEB was 20 pg/mL (the absolute detection limit was 0.02 pg). The relative standard deviation (RSD) for 5 parallel measurements of SEB (1 ng/mL) was 9.2%., (Copyright © 2011 Elsevier B.V. All rights reserved.)

A simple, stable and sensitive electrogenerated chemiluminescence (ECL) detector was developed. It was based on tris(2,2-bipyridyl)ruthenium(II) (Ru(bpy)(3)(2+)) immobilized on the surface of a Pt wire with Nepem-105D ion exchange solution. The detector was prepared by inserting a Pt wire with immobilized Ru(bpy)(3)(2+) (working electrode) into a capillary tube, followed by inserting another Pt wire (counter electrode) in this tube and sealing. ECL behavior was investigated using ofloxacin as an analyte. Under optimal conditions, stable ECL intensity was obtained. This detector has been used in HPLC-ECL for the determination of multiple target fluoroquinolone residues in milk. There is no post column reagent addition, which would dilute the analytes, potentially leading to chromatographic band-broadening. The system is very simple with low dead volume, low baseline and background noise, together with high sensitivity and stability. The as-prepared ECL detector, when was used for the determination of ofloxacin, pefloxacin, enrofloxacin and difloxacin in milk, demonstrated adequate sensitivity to allow quantification of trace FQ levels in commercial milk samples. One or more of the target FQ analytes were present at levels above the LOD of the new ECL detector in each and every one of the 22 milk samples analysed., (Copyright © 2011 Elsevier B.V. All rights reserved.)

A simple, sensitive and rapid flow-injection chemiluminescence (CL) method has been developed for the determination of cefotaxime sodium based on the chemiluminescence reaction of cefotaxime sodium with ceric sulfate and rhodamine 6G in nitric acid solution. The concentration of cefotaxime sodium was proportional with the CL intensity in the range of 4×10(-8)-8×10(-6) mol L(-1). The detection limit (signal-to-noise ratio=3) was 1×10(-8) mol L(-1). Coupled to the technique of on-line microdialysis sampling, this method was successfully applied to study cefotaxime sodium-protein interaction. The drug and protein were mixed in different molar ratios in Ringer's solution, pH 7.4, and incubated at 37°C in a water bath. The microdialysis probe was utilized to sample the mixed solution at a perfusion rate of 5 μL min(-1) and the recovery of cefotaxime sodium under experimental condition was 16.2%. The data obtained by the present Microdialysis-Flow Injection Analysis-CL method was analyzed with the Scatchard analysis and Klotz plot. The estimated association constant (K) and the number of the binding sites (n) on one of BSA molecule were 5.94×10(4) M(-1) and 1.29 (Klotz equation), respectively., (Copyright © 2010 Elsevier B.V. All rights reserved.)

A novel enzyme reactor with co-immobilization of beta-galactosidase and glucose oxidase in calcium alginate fiber (CAF) and amine modified nanosized mesoporous silica (AMNMS) was prepared which incorporate the adsorption and catalysis of AMNMS with the cage effect of the polymer to increase catalytic activity and stability of immobilized enzyme. The enzyme reactor was applied to prepare a chemiluminescence (CL) flow-through biosensor for determination of lactose combined with a novel luminol-diperiodatonickelate (DPN) CL system we reported. It shows that the CL flow-through biosensor possesses long lifetime, high stability, high catalytic activity and sensitivity. The relative CL intensity was linear with the lactose concentration in the range of 8 x 10(-8) - 4 x 10(-6) g mL(-1) with the detection limit of 2.7 x 10(-8) g mL(-1) (3sigma). It has been successfully applied to the determination of lactose in milk., (Copyright 2010 Elsevier B.V. All rights reserved.)

A new molecularly imprinted polymer (MIP)-chemiluminescence (CL) method has been developed for detection of proline. The molecularly imprinted polymer microspheres were synthesized using precipitation polymerization with hydroxyproline, a structural analogue, as the template. Polymer microspheres were immobilized in microtiter plates (96 wells) which selectively adsorbed the analyte (dansyl-proline). After washing, the bound fraction was quantified based on peroxyoxalate chemiluminescence (PO-CL) reaction enhanced by imidazole. The cavity of MIP synthesized with hydroxyproline as template is smaller, which can avoid non-specific adsorption and lead to enhancement of specificity, response speed and sensitivity when recognizing dansyl-proline. Under the optimum conditions, the relative CL intensity has a linear relationship with the concentration of proline in the range of 1x10(-6) mol L(-1) to 4x10(-5) mol L(-1), with a limit of detection 3x10(-7) mol L(-1) (3sigma). The relative standard deviation (R.S.D.) for proline (1x10(-6) mol L(-1), n=7) was 3.7%. The MIP-CL method can become a useful analytical technology for determination of proline in real sample., (Crown Copyright 2010. Published by Elsevier B.V. All rights reserved.)

In this paper, a novel flow injection-chemiluminescence (FI-CL) method was proposed for the determination of ergometrine maleate in serum. The new CL reaction was based on the direct oxidation of ergometrine maleate by the complex of metal chelate diperiodatocuprate(III) (K(5)[Cu(HIO(6))(2)]) in an alkaline medium. The CL intensity was enhanced in the presence of ascorbic acid. Hereby under the optimum conditions, ergometrine maleate was determined over the range of 4.0 x 10(-9) gm L(-1) to 4.0 x 10(-7) gm L(-1) with a limit of detection (3 sigma) of 1.1 x 10(-9) gm L(-1). The relative standard deviation (R.S.D.) was 2.1% for 8.0 x 10(-9) gm L(-1) ergometrine maleate (n=7). The sensitive method was successfully applied to the direct determination of ergometrine maleate (ng mL(-1)) in pharmaceutical injection and serum samples. The mechanism of the reactions was also discussed., ((c) 2009 Elsevier B.V. All rights reserved.)

A novel and high selectivity flow-injection chemiluminescence (FI-CL) system with diperiodatoargentate(III) (DPA) is developed for the determination of uric acid for the first time. It is based on the reaction of diperiodatoargentate(III) (DPA) with uric acid in alkaline medium to emit CL. With the peak height as a quantitative parameter applying optimum working conditions, the relative CL intensity was linear with the uric acid concentration in the range of 4.0 x 10(-7)-2.0 x 10(-4) mol L(-1) with a detection limit of 1.2 x 10(-7) mol L(-1) (3 sigma). The relative standard deviation (RSD) was 2.1% for 5.0 x 10(-5) mol L(-1) uric acid (n=7). The proposed method held higher selectivity than other CL methods and was applied to determination of uric acid in human serum. The possible CL reaction mechanism was also discussed briefly., ((c) 2009 Elsevier B.V. All rights reserved.)

A novel flow-injection chemiluminescence (CL) method for the determination of dihydralazine sulfate (DHZS) is described. The method is based on the reaction of luminol and diperiodatocuprate (K(2)[Cu(H(2)IO(6))(OH)(2)], DPC) in alkaline medium to emit CL, which is greatly enhanced by DHZS. The possible CL mechanism was first proposed based on the kinetic characteristic, CL spectrum and UV spectra. The optimum condition for the CL reaction was in detail studied using flow-injection system. The experiments indicated that under optimum condition, the CL intensity was linearly related to the concentration of DHZS in the range of 7.0x10(-9) to 8.6x10(-7) g mL(-1) with a detection limit (3sigma) of 2.1x10(-9) g mL(-1). The proposed method had good reproducibility with the relative standard deviation 3.1% (n=7) for 5.2x10(-8) g mL(-1) of DHZS. This method has the advantages of simple operation, fast response and high sensitivity. The special advantage of the system is that very low concentration of luminol can react with DPC catalyzed by DHZS to get excellent experiment results. And CL cannot be observed nearly when luminol with same concentration reacts with other oxidants, so luminol-DPC system has higher selectivity than other luminol CL systems. The method has been successfully applied to determine DHZS in serum., (Copyright 2009 Elsevier B.V. All rights reserved.)

We have identified a new functional transmembrane receptor, LRRC19 (leucine-rich repeat containing 19), that belongs to the LRR protein family. LRRC19's central core has four analogous LRR repeating modules in a juxtaposed array and a casein kinase (CK2) phosphorylation site in the cytoplasmic domain. LRRC19 mRNA was found in the kidney, spleen and intestine of adult mice using both RT-PCR and in situ hybridization. LRRC19 does not contain a cytoplasmic Toll/IL-1 receptor (TIR) domain but was able to activate NF-kappaB and induce production of proinflammatory cytokines. LRRC19 shares a close evolutionary relationship with multiple Toll-like receptors (TLRs), especially TLR3. Importantly, the TLR3 ligand, as well as other TLR ligands, significantly promoted the expression of proinflammatory cytokines and the activation of NF-kappaB by LRRC19. Thus, LRRC19 may play an important role in inducing innate immune responses in certain tissues such as the kidney.

Fluorescent nanoparticles (FNs) with unique optical properties may be useful as biosensors in living cancer cell imaging and cancer targeting. In this study, anti-EGFR antibody conjugated fluorescent nanoparticles (FNs) (anti-EGFR antibody conjugated FNs) probe was used to detect breast cancer cells. FNs with excellent character such as non-toxicity and photostability were first synthesized with a simple, cost-effective and environmentally friendly modified Stober synthesis method, and then successfully modified with anti-EGFR antibody. This kind of fluorescence probe based on the anti-EGFR antibody conjugated FNs has been used to detect breast cancer cells with fluorescence microscopy imaging technology. The experimental results demonstrate that the anti-EGFR antibody conjugated FNs can effectively recognize breast cancer cells and exhibited good sensitivity and exceptional photostability, which would provide a novel way for the diagnosis and curative effect observation of breast cancer cells and offer a new method in detecting EGFR.

In this work, a stable electrogenerated chemiluminescence (ECL) detector was developed. The detector was prepared by packing cation-exchanged resin particles in a glass tube, followed by inserting Pt wires (working electrode) in this tube and sealing. The leakage of Ru(bpy)(3)(2+) can be compensated by adding a small amount of Ru(bpy)(3)(2+) into solution phase. Coupled with high-performance liquid chromatography separation, the detector has been used for determination of itopride hydrochloride in human serum. Under the optimal conditions, the ECL intensity has a linear relationship with the concentration of itopride hydrochloride in the range of 1.0 x 10(-8) g mL(-1) to 1.0 x 10(-6) g mL(-1) and the detection limit was 3 x 10(-9) g mL(-1) (S/N=3). The as-prepared ECL detector displayed good sensitivity and stability.

A simple and sensitive liquid chromatographic method coupled with electrogenerated chemiluminescence (ECL) was described for the separation and quantification of naproxen in human urine. The method was based on the ECL of naproxen in basic NaNO(3) solution with a dual-electrode system. Factors affected the ECL emission were investigated. Under the optimal conditions, the ECL intensity has a linear relationship with the concentration of naproxen in the range of 4.0 x 10(-8)g mL(-1) to 2.0 x 10(-6)g mL(-1) and the detection limit was 1.6 x 10(-8)g mL(-1) (S/N=3). Application of the method to the analyses of naproxen in human urine proved feasible.

Background: IFN regulatory factor 4-binding protein (IBP) is a novel type of activator of Rho GTPases. It has been linked with differentiation and apoptosis of lymphocytes, but its function in oncogenesis remains unclear. Here we studied the expression of endogenous IBP in four human colorectal cancer cell lines, normal, adenoma and tumor colorectal tissues., Methods: Molecular (Western blot and RT-PCR), and confocal analyses were used to investigate IBP expression in human colorectal cancer cell lines. Matched normal and tumor tissue sections of 63 patients and 15 adenoma tissue sections were analyzed for IBP expression by immunohistochemistry (IHC)., Results: IBP was ubiquitely expressed in human colorectal cancer cell lines. The expression of IBP can be detected at both the mRNA and protein level in SW480, SW620 and HT29 cells. Clinically, IBP were elevated in human colorectal cancer specimens in comparison to normal colorectal tissues. Substantial high expression of IBP was observed in colorectal cancer tissues (67%), whereas corresponding normal tissues and 15 adenoma tissues showed consistently absent immunoreactivity of IBP. Moreover, IBP expression is correlated with the differentiation level of colorectal cancer cells (p<0.05) and clinical stage of patients (p<0.01)., Conclusions: Our data show, for the first time, a dysregulated expression of IBP in human colorectal cancer, offering new perspectives for its role in cancer development and progression. IBP may be a novel tumor marker and a therapeutic target for colorectal cancer.

A novel method for determination of indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) in an extract from mung bean sprouts using high performance liquid chromatography (HPLC) with chemiluminescence (CL) detection is described. The method is based on the CL reaction of auxin (indole-3-acetic acid and indole-3-butyric acid) with acidic potassium permanganate (KMnO(4)) and tris(2,2'-bipyridyl)ruthenium(II), which was immobilized on the cationic ion-exchange resin. The chromatographic separation was performed on a Nucleosil RP-C18 column (i.d.: 250 mm x 4.6 mm, particle size: 5 microm, pore size: 100) with an isocratic mobile phase consisting of methanol-water-acetic acid (45:55:1, v/v/v). At a flow rate of 1.0 mL min(-1), the total run time was 20 min. Under the optimal conditions, the linear ranges were 5.0x10(-8) to 5.0x10(-6)g mL(-1) and 5.0x10(-7) to 1.0x10(-5)g mL(-1) for IAA and IBA, respectively. The detection limits were 2.0x10(-8)g mL(-1) and 2.0x10(-7)g mL(-1) for IAA and IBA, respectively. The relative standard deviation (RSD) of intra-day were 3.1% and 2.3% (n=11) for 2x10(-6)g mL(-1) IAA and 2x10(-6)g mL(-1) IBA; The relative standard deviations of inter-day precision were 6.9% and 4.9% for 2x10(-6)g mL(-1) IAA and 2x10(-6)g mL(-1) IBA. The proposed method had been successfully applied to the determination of auxin in mung bean sprouts.

Fluorescent nanoparticles (FNPs) with unique optical properties may be useful as biosensors in living cancer cell imaging and cancer targeting. A novel kind of polymer fluorescent nanoparticles (PFNPs) was synthesized and its application for ovarian cancer imaging with fluorescence microscopy imaging technology was presented in this study. The PFNPs were synthesized with precipitation polymerization by using methacrylic acid (MAA) as monomer, trimethylolpropane trimethacrylate (Trim) as cross-linker, azobisisobutyronitrile (AIBN) as radical initiator and butyl rhodamine B (BTRB) as fluorescent dye. And the fluorescent dye was embedded into the three-dimensional network of the polymer when the polymer was produced. With this method the PFNPs can be prepared easily. And then the PFNPs were successfully modified with anti-Her-2 monoclonal antibody. The fluorescence probe based on anti-Her-2 monoclonal antibody conjugated PFNPs has been used to detect ovarian cancer cells with fluorescence microscopy imaging technology. The experimental results demonstrate that the anti-Her-2 monoclonal antibody conjugated PFNPs can effectively recognize ovarian cancer cells and exhibit good sensitivity and exceptional photostability, which would provide a novel way for the diagnosis and curative effect observation of ovarian cancer cells.

This paper developed optical fiber sensor based on molecular imprinted polymer as artificial recognition element for the determination of 6-mercaptopurine (6-MP) in human serum. This approach displayed high sensitivity by oxidizing 6-MP to a strong fluorescent compound with H(2)O(2) in the alkaline media. It offered a relatively nice selectivity for 6-MP detection by molecular imprinted polymer's recognition. The relative standard deviation (R.S.D.) was 5% for a same sensor (n=5) when 6-MP concentration was 1.0 x 10(-7)gm L(-1) in serum. The developed method was satisfactorily applied to the determination of 6-MP in human serum without any necessity for sample treatment or time-consuming extraction steps prior to the analysis.

Ofloxacin (OFLX) exhibited strong electrogenerated chemiluminescence (ECL) in NaNO(3) solution with a dual-electrode system when constant current was exerted. Based on this observation, a sensitive direct ECL method coupled with high-performance liquid chromatography (HPLC) separation was developed for determination of OFLX in human serum. Factors affected the ECL emission were investigated. Under the optimal conditions, the ECL intensity has a linear relationship with the concentration of OFLX in the range of 1.0x10(-8) to 4.0x10(-6) g mL(-1) and the detection limit was 4x10(-9) g mL(-1) (S/N=3). The proposed method was sensitive, simple and convenient to operate.

The method of synthesis and evaluation of molecularly imprinted polymers was reported. As a selective solid-phase extraction sorbent, the polymers were coupled with electrochemical fluorimetry detection for the efficient determination of methotrexate in serum and urine. Methotrexate was preconcentrated in the molecularly imprinted solid-phase extraction microcolumn packed with molecularly imprinted polymers, and then eluted. The eluate was detected by fluorescence spectrophotometer after electrochemical oxidation. The conditions of preconcentration, elution, electrochemical oxidation and determination were carefully studied. Under the selected experimental conditions, the calibration graph of the fluorescence intensity versus methotrexate concentration was linear from 4x10(-9) g mL(-1) to 5x10(-7) g mL(-1), and the detection limit was 8.2x10(-10) g mL(-1) (3sigma). The relative standard deviation was 3.92% (n=7) for 1x10(-7) g mL(-1) methotrexate. The experiments showed that the selectivity and sensitivity of fluorimetry could be greatly improved by the proposed method. This method has been successfully applied to the determination of methotrexate. At the same time, the binding characteristics of the polymers to the methotrexate were evaluated by batch and dynamic methods.

In this study, a new chemiluminescence (CL) flow-through biosensor for glucose was developed by immobilizing glucose oxidase (GOD) and horseradish peroxidase (HRP) on the eggshell membrane with glutaraldehyde as a cross-linker. The CL detection involved enzymatic oxidation of glucose to D-gluconic acid and hydrogen peroxide (H2O2) and then H2O2 oxidizing luminol to produce CL emission in the presence of HRP. The immobilization condition (e.g., immobilization time, GOD/HRP ratio, glutaraldehyde concentration) was studied in detail. It showed good storage stability at 4 degrees C over a 5-month period. The proposed biosensor exhibited short response time, high sensitivity, easy operation, and simple sensor assembly, and the proposed biosensor was successfully applied to the determination of glucose in human serum.

Monitoring hydrogen peroxide (H(2)O(2)) in aqueous cigarette smoke condensate (CSC) is helpful for interpreting the relationship between cigarette smoke and oxidative stress, inflammation and disease. It is also significative for elucidating the pathogenic effects of CSC. In this paper, a novel flow-injection chemiluminescence (FI-CL) method was well established for determination of H(2)O(2) in the complex sample CSC which did not need pretreatment. The sensitive and selective method is based on the CL reaction of luminol with low concentration (10(-7) molL(-1)) and H(2)O(2) at low concentration level (<10(-8) molL(-1)) in an alkaline medium catalyzed by a complex K(5)[Cu(HIO(6))(2)] (DPC), which has proved no interference of other metal ions or horseradish peroxidase (HRP). The proposed method had been used to determine trace amount of H(2)O(2) with a limit of detection (3sigma) of 4.1 x 10(-11) molL(-1), which enables minimal amount of sample for analysis. A satisfactory result has been gained for the determination of H(2)O(2) in CSC sample by use of the proposed method. The concentration of H(2)O(2) in two reference cigarette (84 cm, Longfeng) smoke condensate have been determined at 4-6 micromolL(-1) level.

A novel fluoroimmunoassay (FIA) method was developed for the determination of tumor necrosis factor-alpha (TNF-alpha) in this study. The proposed method has the advantage of showing the specificity of immunoassays and sensitivity of fluorescent nanoparticles label technology. With the well-established inverse microemulsion polymerisation process, the tris(2',2-bipyridyl)dichlororuthenium(II) hexahydrate (Rubpy)-doped fluorescent silica nanoparticles (RuDFSNs) were prepared. Then a RuDFSNs-labeled anti-TNF-alpha monoclonal antibody was prepared and used for FIA of TNF-alpha in human serum samples with a sandwich FIA by using the low fluorescent 96-well transparent microtiter plates. The assay response was linear from 1.0 to about 250.0pg/mL with a detection limit of 0.1pg/mL for TNF-alpha. The intra- and inter-assay precision are 4.9%, 4.4%, 4.6%; 6.1%, 5.9%, 5.3% for five parallel measurements of 2.0, 20.0, 200.0pg/mL TNF-alpha respectively, and the recoveries are in the range of 96-104% for human serum sample measurements by standard-addition method. We also explored the application of fluorescence microscopy imaging in the study of the FIA for TNF-alpha with the fluorescent nanoparticle labels. The results demonstrate that the method offers potential advantages of sensitivity, simplicity and good reproducibility for the determination of TNF-alpha, and is applicable to the determination of TNF-alpha in serum samples and being capable of fluorescence microscopy imaging for the determination of TNF-alpha.

A sensitive and homogeneous immunoassay (IA) based on capillary electrophoresis (CE) with enhanced chemiluminescence (CL) detection has been developed for the determination of hepatitis B surface antigen (HBsAg) and antibody (HBsAb) in human serum. The conditions for the CL reaction and electrophoresis were investigated in detail using horseradish peroxidase (HRP) labeled HBsAg (HBsAg*) as a marker because of its catalytic effects on the luminol-hydrogen peroxide reaction. The CL reaction was enhanced by para-iodophenol and the CL detector was designed uniquely without any dead volume or diluents effect. The present method has been used for assaying HBsAg and HBsAb in human serum using a competitive format and a non-competitive format, respectively. Under the optimal conditions, the linear ranges were from 1 to 400 pmol/L (R=0.9988) for HBsAg and 2 to 200 mIU/mL (R=0.9981) for HBsAb. The detection limits were 0.4 pmol/L and 1 mIU/mL for HBsAg and HBsAb, respectively. The relative standard deviations of peak area were 4.2% and the errors of it were from -0.03% to +0.05% for 80 pmol/L HBsAg* (n=7). In this study, the free HBsAg* and the bound HBsAg* (HBsAg*-HBsAb) were separated in the separation capillary within 6 min using a borate run buffer. To verify the experimental reliability, the result was comparable with that of enzyme linked immunosorbent assay (ELISA) and demonstrated the feasibility of the CE-CL immunoassay method for clinical diagnosis.

A simple, rapid, sensitive and reproducible spectrophotometry for determination of ultra trace organophosphorus pesticides (OPs) with liquid core waveguide light intensity technique is presented. OPs were degraded into phosphate with UV light, potassium peroxydisulphate as oxidant and nanosized titanium dioxide as catalyst. Under the optimum selected conditions, linear light intensity response was obtained in the range of 2.0 x 10(-11) to 8.0 x 10(-10)g mL(-1) phosphate, and the limit of detection (LOD) 6.7 x 10(-12)g mL(-1) was achieved. Both the low limit of linear range and the LOD of the proposed method were lower over 1000-fold than that of classical spectrophotometry. The proposed method was applied to the determination of ultra trace OPs in vegetables and fruits samples.

A novel method was developed for the simultaneous determination of glucocorticoid residues such as triamcinolone (TR), prednisolone (PR), hydrocortisone (HC), cortisone (CO), methylprednisolone (MP), dexamethasone (DE) and triamcinolone acetonide (TA) by high-performance liquid chromatography (HPLC) coupled with chemiluminescence (CL) detection. The procedure was based on the enhancement effect of glucocorticoids on the chemiluminescence reaction between luminol and the complex of trivalent copper and periodate ([Cu(HIO6)2]5-), which was on-line electrogenerated by constant current electrolysis. The HPLC separation used a Nucleosil RP-C18 column (250 mmx4.6 mm i.d., 5 microm, pore size, 100 A) with a mobile phase consisting of acetonitrile and 1.0 mmol L(-1) ammonium acetate (pH 6.8, 40:60,v/v) at a flow rate of 0.8 mL min(-1). The effects of several parameters on the HPLC resolution and CL emission were studied systematically. Liver samples were hydrolyzed with Helix pomatia juice followed by a solid-phase extraction procedure. Under optimum conditions, the limits of detection (LOD) at a signal-to-noise of 3 ranged from 0.08 to 1.0 ng g(-1) and the limits of quantification (LOQ) at a signal-to-noise of 10 ranged from 0.27 to 3.33 ng g(-1) for seven glucocorticoids. The relative standard deviations (RSD) of intra- and inter-day precision were below 6.8%. The average recoveries for glucocorticoids (spiked at the levels of 5-50 ng g(-1)) in pig liver ranged from 88 to 106%, and the relative standard deviations of the quantitative results were from 2.0 to 6.9%. The proposed method had been successfully applied to the determination of glucocorticoid residues in pig liver.

The paper presented a novel chemiluminescence (CL) immunoassay method, which combines the advantages of traditional enzyme-linked immunosorbent assays (ELISA) and bis (2,4,6-trichlorophenyl) oxalate (TCPO)-hydrogen peroxide CL detection system. A fluorescent product 2,3-diaminophenazine (DAPN) was produced by reaction between o-phenylenediamine (OPDA, 1,2-diaminobenzene) and H(2)O(2) catalyzed by horseradish peroxidase (HRP). DAPN was excited by the reactive intermediate of TCPO-H(2)O(2) chemiluminescent reaction, and led to CL. The dependence of the CL intensity on the concentrations of antigen was studied. As analytical application, the proposed method was used for determination of recombinant human interleukin 6 (rHu IL-6) and beta-human chorionic gonadotropin (beta-HCG). Under the selected experimental conditions, a linear relationship was obtained between the CL intensity and the concentration of rHu IL-6 in the range of 4.0-625.0pg/ml, and beta-HCG in the range of 12.5-400.0mIU/ml. The detection limits were 0.5pg/ml for rHu IL-6 and 3mIU/ml for beta-HCG with relative standard deviation of 2.3 for 78.0pg/ml rHu IL-6, and 3.9 for 50.0mIU/ml beta-HCG. This method has been applied to the determination of rHu IL-6 in human serum and beta-HCG in urine with satisfactory results.

Sensitive, rapid and inexpensive chemiluminescence (CL) imaging has been developed based on molecular imprinted polymer (MIP) sensing elements. Imprinted uniform microspheres were synthesized by precipitation polymerization. Microtiter plates (96 wells) were coated with polymer microspheres imprinted with trans-resveratrol, which were fixed in place using poly(vinyl alcohol) (PVA) as glue. The amount of polymer-bound trans-resveratrol was quantified using imidazole (IMZ)-catalyzed peroxyoxalate chemiluminescence (PO-CL) reaction. The light produced was then measured with a high-resolution CCD camera. Calibration curve corresponding to analyte concentration ranging from 0.3 to 25 microg mL(-1) was obtained with a limit of detection 0.1 microg mL(-1). These results showed that the MIP-based CL imaging sensor can become a useful analytical tool for quick simultaneous detection of trans-resveratrol in a large number of real samples.

In this paper, a chemiluminescence (CL) micro-flow system combined with on-line solid phase extraction (SPE) is presented for determination of beta-lactam antibiotics (penicillin, cefradine, cefadroxil, cefalexin) in milk. It is based on the enhancement effect of beta-lactam antibiotics on the luminol-K3Fe(CN)6 CL system. The micro-flow system was fabricated from two polymethyl methacrylate (PMMA) plates (50 mm x 40 mm x 5 mm) with the microchannels of 200 microm wide and 150 microm deep. C18-modified silica gel was packed into the microchannel (length: 10 mm; width: 1 mm; depth: 500 microm) to serve as SPE device. Extraction and preconcentration of the analytes were carried out using on-line SPE micro-flow system and the selectivity of CL detection was improved. The detection limits were 0.5 microg mL(-1) of penicillin, 0.04 microg mL(-1) of cefradine, 0.08 microg mL(-1) of cefadroxil and 0.1 microg mL(-1) of cefalexin. The proposed method was also applied to analyze the beta-lactam antibiotics in milk. Experimental results were in good agreement with those obtained by high performance liquid chromatography (HPLC) method with UV detection.

In this paper, a novel gold nanoparticles based protein immobilization method was designed. Biocomposites of gold nanoparticles and proteins were successfully coated on poly(methyl methacrylate) (PMMA) plates and polystyrene microtiter plates. The proteins could be immobilized on solid materials with high density and better bioactivity. Based on above design, chemiluminescence (CL) imaging assay for determination of H(2)O(2) and recombinant human interleukin-6 (rHu IL-6) was developed. The linear range and the loading capability were greatly improved when compared with imaging assay performed with direct proteins immobilization. Under the selected experimental conditions, a linear relationship was obtained between the CL intensity and the concentration of H(2)O(2) in the range of 1.0 x 10(-6) to 1.0 x 10(-4) mol L(-1), and rHu IL-6 in the range of 2.0-312.0 pg mL(-1). The detection limits were 2 x 10(-7) mol L(-1) (3sigma) for H(2)O(2) and 0.5 pg mL(-1) for rHu IL-6 with relative standard deviation of 3.8% for 3.0 x 10(-5) mol L(-1) H(2)O(2), and 4.4% for 39.0 pg mL(-1) rHu IL-6. This method has been applied to the determination of rHu IL-6 in human serum with satisfactory results.

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.

The determination of indomethacin (INM) in pharmaceutical and biological samples by means of high-performance liquid chromatography (HPLC) with in situ electrogenerated Mn(III) chemiluminescence (CL) detection was proposed. The method was based on the direct CL reaction of INM and Mn(III), which was in situ electrogenerated by constant current electrolysis. The chromatographic separation was carried out on Nucleosil RP-C(18) column (250 mm x 4.6 mm; i.d., 5 microm; pore size, 100 A) at 20 degrees C. The mobile phase consisted of methanol:water:acetic acid=67:33:0.1 solution. At a flow rate of 1.0 mL min(-1), the total run time was 10 min. The effects of several parameters on the HPLC resolution and CL emission were studied systematically. Under the optimal conditions, a linear range from 0.01 to 10 microg mL(-1)(R(2)=0.9991), and a detection limit of 8 ng mL(-1) (signal-to-noise ratio=3) for INM were achieved. The relative standard deviations (R.S.D.) for 0.1 microg mL(-1) INM were 2.2% within a day (n=11) and 3.0% on 5 consecutive days (n=6), respectively. The recovery of INM from urine samples was more than 92%. The applicability of the method for the analysis of pharmaceutical and biological samples was examined.

In this paper, a novel electrochemiluminescence (ECL) imaging sensor array was developed for determination of hydrogen peroxide (H2O2), which was based on Cu/Zn alloy galvanic cell generated ECL. In alkaline solution, Cu/Zn galvanic cell was formed because of corrosion effect, the galvanic cell could supply stable potential for ECL generation of luminol, and the weak ECL emission could be enhanced by H(2)O(2). The galvanic cell sensor array was designed by putting Cu/Zn alloy in 96-well microtiter plates separately. The relative ECL intensity was proportional with the concentration of hydrogen peroxide in the range of 1.0 x 10(-6) to 1.0 x 10(-4) mol l(-1) and the detection limit was 3.0 x 10(-7) mol l(-1) (3sigma), the relative standard deviation (R.S.D.) for 11 parallel measurements of 1.0 x 10(-5)mol l(-1) H2O2 was 4.0%.

The determination of four Sudan dyes by means of high-performance liquid chromatography (HPLC) with chemiluminescence (CL) detection was proposed. The method was based on the enhancement effect of Sudan dyes on the chemiluminescence reaction between luminol and BrO-, which was on-line electrogenerated by constant current electrolysis. The separation was carried out on Nucleosil RP-C18 column (250 mm x 4.6 mm i.d., 5 microm, pore size, 100 A) at 35 degrees C. The mobile phase consisted of a V (methanol): V (0.2% aqueous formic acid) = 90:10 solution. At a flow-rate of 1.0 ml min(-1), the total run time was 25 min. The effects of several parameters on the HPLC resolution and CL emission were studied systematically. For the four Sudan dyes, the limits of detection (LOD) at a signal-to-noise of 3 ranged from 4 to 8 microg kg(-1) and the limits of quantification (LOQ) at a signal-to-noise of 10 ranged from 13 to 27 microg kg(-1). The relative standard deviations (RSD) of intra-and inter-day precision were below 4.4%. The average recoveries for all four Sudan dyes (spiked at the levels of 1.0 and 1.5 mg kg(-1)) in chilli tomato sauce and hot chilli pepper ranged from 94% to 105%, and the relative standard deviations of the quantitative results were from 2.5 to 4.2%. The proposed method had been successfully applied to the determination of four Sudan dyes in hot chilli products.

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.

Based on a molecularly imprinted polymer (MIP) as the recognition element, a novel chemiluminescence (CL) micro flow sensor on a chip for the determination of terbutaline in human serum is described. The MIP was prepared by using terbutaline as the template, methacrylic acid (MAA) as the functional monomer, ethylene glycol dimethacrylate (EGDMA) as the cross-linking monomer, and acetonitrile as the solvent. The chip was fabricated from two 50 mm x 40 mm x 5 mm transparent poly (methylmethacrylate) (PMMA) slices. The microchannels on the chip etched by CO(2) laser were 200 microm wide and 150 microm deep. The microsensor cell filled with 2mg MIP for selectively on line adsorbing terbutaline was 10 mm long, 1 mm wide, and 0.5 mm deep. All reagents were controlled by the syringe pump with an accurate timer. The on line adsorbed terbutaline by the MIP can enhance the CL intensity of the reaction of luminol with ferricyanide. The enhanced CL intensity is linear with terbutaline concentration from 8.0 to 100 ng/mL with a detection limit of 4.0 ng/mL (3sigma). The micro flow sensor provides for good reproducibility with the relative standard deviation of 3.6% (n=7) for 20 ng/mL terbutaline.

A flow-injection chemiluminescence (CL) system is proposed for simultaneous determination of Co(2+) and Cu(2+) using partial least squares (PLS) calibration. This method is based on the fact that both Co(2+) and Cu(2+) catalyse the CL reaction of luminol-H(2)O(2), and that their kinetic characteristics of Co(2+) and Cu(2+) are significantly different in the luminol-H(2)O(2) system. The CL intensity was measured and recorder at different reaction times of luminol-H(2)O(2)Co(2+)Cu(2+), and the obtained data were processed by the chemometric approach of partial least squares. The experimental calibration set was composed of 16 sample solutions using an orthogonal calibration design for two component mixtures. The proposed method offers the potential advantages of high sensitivity, simplicity and rapidity for Co(2+) and Cu(2+) determination, and was successfully applied to the simultaneous determination of both analytes in real water sample. The present paper demonstrated that the simultaneous determination of two metal ions without any prior separation has been possible using flow-injection CL system.

A novel and sensitive chemiluminescence (CL) method for the determination of aminomethylbenzoic acid and aminophylline coupled with flow-injection analysis (FIA) technique is developed in this paper. It is based on the inhibition effect of the studied drugs on the chemiluminescence emission of N-bromosuccinimide-luminol (NBS-luminol) system. Under the optimum conditions, the decreased CL intensity is linear with the concentration of aminomethylbenzoic acid in the range of 2x10(-8) to 1.0x10(-6)gml(-1) and with the concentration of aminophylline in the range of 1x10(-7) to 7.0x10(-6)gml(-1), respectively. The detection limit is 7.0x10(-9)gml(-1) for aminomethylbenzoic acid (3sigma) and 3.4x10(-8)gml(-1) for aminophylline (3sigma). The relative standard deviations (R.S.D.) for 11 parallel measurements of 2.0x10(-7)gml(-1) aminomethylbenzoic acid and 1.0x10(-6)gml(-1) aminophylline are 2.6 and 3.0%, respectively. The proposed methods have been applied for the determination of the studied drugs in their pharmaceutical formulations with satisfactory results. The possible use of the proposed system for the determination of aminomethylbenzoic acid in plasma sample was also tested. The possible inhibition mechanism of aminomethylbenzoic acid and aminophylline on luminol-NBS system was discussed briefly.

A novel chemiluminescence (CL) system for automatic determination of chemical oxygen demand (COD) combined with flow injection analysis is proposed in this paper. In this system, potassium permanganate is reduced to Mn(2+) which is first adsorbed on a strongly acid cation-exchange resin mini-column to be concentrated during chemical oxidation of the organic compounds at room temperature, while the excessive MnO(4)(-) passes through the mini-column to be waste, then the concentrated Mn(2+) is eluted reversely and measured by the luminol-H(2)O(2) CL system. The calibration graph is linear in the range of 4-4000 mg l(-1) and the detection limit is 2 mg l(-1). A complete analysis could be performed in 1.5 min including washing and sampling, giving a throughout of about 40 h(-1). The relative standard deviation was 4.4% for 10 mg l(-1) COD (n=11), 4.8% for 100 mg l(-1) COD (n=11). This CL flow system for determination of COD is very simple, rapid and suitable for automatic and continuous analysis. The presented system has been applied successfully to the determination of COD of water samples.

A novel chemiluminescence (CL) detection scheme has been developed for detecting underivatized amino acids following capillary electrophoresis (CE) separation. This detection was based on the inhibitory effect of amino acids on the CL reaction between luminol and BrO(-) in alkaline aqueous solution. Detection of amino acids was accomplished with a borate-based background electrolyte at pH 9.2. The luminol was used as a component of the separation carrier electrolyte. Parameters affecting CE-CL separation and detection, such as the pH value, the concentration of electrolyte and CL reagent on the resolution were optimized. The relative standard deviation for the analysis of amino acids was less than 1.5% for the migration time and 4% for the peak height. The mass limits of detection were from 7 to 144 fmol for the 7 amino acids. This method has been applied of 7 amino acids in amino acid injection.

A chemiluminescence (CL) biosensor on a chip coupled to microfluidic system is described in this paper. The CL biosensor measured 25x45x5 mm in dimension, was readily produced in analytical laboratory. Glucose oxidase (GOD) was immobilized onto controlled-pore glass (CPG) via glutaraldehyde activation and packed into a reservoir. The analytical reagents, including luminol and ferricyanide, were electrostatically co-immobilized on an anion-exchange resin. The most characteristic of the biosensor was to introduce the air as the carrier flow in stead of the common solution carrier for the first. The glucose was sensed by the CL reaction between hydrogen peroxide produced from the enzymatic reaction and CL reagents, which were released from the anion-exchange resin. The proposed method has been successfully applied to the determination of glucose in human serum. The linear range of the glucose concentration was 1.1-110 mM and the detection limit was 0.1 mM (3sigma).

A novel chemiluminscence (CL) flow-through sensor for ofloxacin is described. It was based on the sensitizing effect of ofloxacin on the CL oxidation of sulfite by PbO(2) in H(2)SO(4) media. By a very simply means, the solid-phase PbO(2) was immobilized inside of the CL flow cell as CL oxidant. The column of solid PbO(2) could be reused about 400 times during a period of 50 h. The calibration graph is linear in the range 0.2-10 mug ml(-1) with a detection limit of 7.8x10(-8) g ml(-1) (S/N=3). This method has been successfully applied to determine ofloxacin in pharmaceutical preparation.