Flow-injection Chemiluminescence Determination of Catecholamines

A flow injection chemiluminescence (CL) method for the determination of catecholamines is described which is based on their inhibition of the intensity of CL from the luminol-hypochlorite system The hypochlorite was electrogenerated on-line by a constant current electrolysis, resulting in the elimination of the instability of the hypochlorite solution prepared from a commercial reagent of sodium hypochlorite. The detection limits are 0.6 ng/ml for dopamine, 0.8 ng/ml for adrenaline and isoprenaline. The proposed method has been successfully applied to the determination of catecholamines in pharmaceutical injections.

Determination of Gossypol in Trace Level by Flow Injection Analysis with Chemiluminescence Detection

This work reports the single-molecule detection of gossypol by flow injection analysis with chemiluminescence method. The method is based on the reaction of luminol with ferricyanid in sodium hydroxide medium sensitized by gossypol. Under the optimum conditions, the CL intensity is proportional to the concentration of gossypol over the range of 1.11×10^-17-2.78×10^-16 mol/L in acid solution and 8.00×10^-11-7.39×10^-8mol/L in neutral solution with correlation coefficients 0.9983 and 0.9905, respectively. The detection limits is 1.60×10^-18 mol/L （S/N=3）. The proposed method has been applied for the determination of the gossypol in cottonseeds and pharmaceutical formulations with satisfactory results.

Determination of Ciprofloxacin by Flow Injection Analysis Based on Chemiluminescence System

A novel flow injection chemiluminescence （CL） method for the determination of ciprofloxacin （CPLX） was reported. The proposed method is based on luminescence produced by KMnO4-Na2S2O4-Tb^3＋-CPLX chemiluminescence （CL） system. The effects of some critical experimental conditions were discussed and the optimization of working conditions was investigated. The linear dynamic range is 3.00 × 10^-8 - 9.00 × 10^-7 mol ·L-1 and the detection limit for CPLX is 4.40 × 10^-9 mol·L^-1. This method was applied to the determination of CPLX in tablet, urine, and serum samples and the recoveries of real sample analyses were in the range from 110 ± 4 to 104 ± 4.

Study on Chemiluminescence Reactions of L ucigenin and Reductants by Flow Injection Analysis

The chemiluminescence reactions between lucigenin and reductants such as Mo(LII),V( II), U(III), W(III), Cr(II), Ti(III) and Fe( II), which were produced on-line by passing Mo(VI),V(V),U(VI), W(VI), Cr(VI,III),Ti(IV) and Fe(III) through a micro Jones column, are studied in detail. Results show that the reactions can be used directly for the determination of these substances. The mechanism of the reactions is also investigated.

Study on Quenching Effect of Holmium (Ⅲ) Ion in Chemiluminescence System of Luminol H_2O_2-Cr(Ⅲ) by Flow Injection Technique

A new chemiluminescence (CL) analytical method for determination of rare earth Ho(Ⅲ) ion is reported. It is based on the quenching effect of Ho(Ⅲ) ion on CL intensity of Luminol H 2O 2 Cr(Ⅲ) system. The detection limit is 3×10 -8 mol/L, the linear range is from 1×10 -7 to 1×10 -4 mol/L; the relative standard deviation is less than 3% (for 2×10 -7 mol/L Ho, n=11). The method was applied to determination of Ho(Ⅲ) in pure samples with satisfactory results.

A Novel Flow Injection Chemiluminescence System for the Determination of Reserpine

A novel flow injection cheminescence (FICL) system for the determination of reserpine is presented in this paper. It is based on the CL reaction of reserpine, IO - 4 and H 2O 2 in H 2SO 4 medium. The CL intensity was correlated with concentration of reserpine in the range of 1.0×10 -6～1.0×10 -4 g/mL with a detection limit of 1.35×10 -7 g/ mL. The relative standard deviation is 2.63% for 11 measurements of 2×10 -5 g/mL reserpine standard solution. The method has been applied to the determination of reserpine in pharmaceutical preparations and the results are in good agreement with that of the standard method.

Determination of ribavirin by flow injection chemiluminescence

Objective： To establish a rapid and precise continuous flow-injection chemiluminescence （CL） method to determine ribavirin. Methods： The ribavirin could restrain strongly CL reaction of luminol in sodium hydroxide （NaOH） solution with potassium chlorate （KClO3）. The different experimental parameters affecting the CL intensity were studied carefully. Results： Under optimum conditions （The concentrations of luminol, KClO3, and NaOH were at 0.1 mmol/L, 0.5μmol/L, and 0.2 mol/L, respectively）, the linear range of the working curves was 0.01-7.00μg/ml with a detection limit of 0.004μg/ml. Conclusion： The method is simple, rapid and sensitive, and successfully applied to the determination of ribavirin in pharmaceutical preparations and biological fluids.

Flow injection chemiluminescence determination of meloxicam using potassium permanganate and formaldehyde system

A simple, rapid and sensitive flow injection chemiluminescence （FI-CL） method has been developed for the determination of meloxicam. The method is based on the CL-emitting reaction between meloxicam and potassium permanganate in a hydrochloric acid medium, enhanced by formaldehyde （HCHO）. Under optimum conditions, calibration curve over the range of 1.0-20.0μg/mL was obtained. The proposed method was successfully applied to the determination of meloxicam in capsules with no evi- dence of interference from common excipients. The detection limit of this method was 25.6 ng/mL. The relative standard deviation was 2.1% for 10.0 μg/mL meloxicam. The sample throughput was found to be 120 samples/h.

Flow Injection Analysis of Histidine with Enhanced Electrogenerated Chemiluminescence of Luminol

A simple and sensitive flow injection method is presented for the determination of histidine based on its enhancement of electrogenerated chemiluminescence (ECL) of luminol. After optimization of the experimental parameters, the working range for histidine was in 1.0 x 10-6 to 1.0 x 10 -3 mol/L with a detection limit (S/N = 3) of 0.56 mmol/L. The relative standard deviation was 1.6% for 11 measurements of 5 x 10 5 mol/L histidine solution. The proposed method has been successfully applied to the determination of histidine in real pharmaceutical preparation.

Flow Injection Chemiluminescence Analysis of Low Level Concentration of Hydrazine

Combined with flow-injection (FI) technology, a simple chemiluminescence (CL) method was developed for hydrazine determination in this paper. It was found that hydrazine could greatly decrease the strong CL signal produced by the reaction between luminol and hexacyanoferrate (III) in alkaline medium. The decreased CL intensity was linear with hydrazine concentration in the range of 5.0×10-9 g·mL-1 to 4.0×10-5 g·mL-1, and the limit of detection was 2.0×10-9 g·mL-1 (3σ) with a relative standard deviation of 2.4~4.1% (n=5).

Chemiluminescence Determination of Molybdenum by on-Line Reduction with a Flow Injection System

The chemiluminescence (CL) reaction between lucigenin (Lu) and molybdenum (III) produced by a Jones reductor was investigated using a flow injection system. On the basis of this, a novel method for the determination of trace amount of molybdenum has been established. The emission intensity was linear with molybdenum concentration in the range of 0.1-1000 ng/mL; the detection limit was 0.02 ng/mL molybdenum; the relative standard deviation was less than 2% for the determination of 0.1 ng/mL molybdenum (n=11). The method has been applied successfully to the analysis of trace molybdenum in water and steel samples.

Flow-injection chemiluminescence determination of tryptophan using galangin-potassium permanganate-polyphosphoric acid system

A high sensitive flow-injection chemiluminescence （FI-CL） method for the determination of tryptophan has been developed. The method is based on the chemiluminescence reaction of galangin-potassium permanganate-tryptophan in polyphosphoric acid （PPA） media. Under the optimized conditions, tryptophan was determined in the range 0.05-10 μg/mL with the detection limit （3tr） of 5.0 × 10^-3 μg/mL. The relative standard deviation （RSD） was 1.0% for 11 replicate determinations of 1.0 μg/mL tryptophan. Three synthetic samples were determined selectively with recoveries in the range from 99.6% to 102.0% in the presence of other amino acids.

Flow-Injection Enhanced Chemiluminescence Method for Determination of Penicillamine

A new flow-injection procedure has been developed for the determination of penicillamine based on the enhancement of the chemiluminescence(CL) reaction of the penicillamine-cerium(Ⅳ)-hydrocortisone system. The method was simple, selective and sensitive with a detection limit of 6.2×10-5 mol·L-1(S/N=3). It was applicable to the determination of penicillamine in the concentration range of 2×10-6～5×10-4 mol·L-1. The method was successfully applied to the determination of penicillamine in tablets. The relative standard deviation (RSD) was 1.42% (n=7) and the recovery was 97%～103% (n=4).

Simultaneous Determination of Gold and Platinum by Double Artificial Neural Network Analysis with Flow-injection Chemiluminescence

A highly sensitive double artificial neural network （DANN） analysis with flow-injection chemiluminescence （FI-CL） has been developed to simultaneously determine the trace amounts of the gold and platinum in simulated mixed samples, without the boring process.

DETERMINATION OF TETRACYCLINE AND OXYTETRACYCLINE BY FLOW-INJECTION CHEMILUMINESCENCE METHOD

Objective To establish a rapid and precise continuous flow-injection chemiluminescence method for the determination of tetracycline and oxytetracycline. Methods In NaOH solution, tetracycline and oxytetracycline can sensitize obviously the chemiluminesence (CL) intensity of the reaction of luminol with KIO_4, the sensitized CL intensity is proportional to the concentration of tetracycline and oxytetracycline. So, a new flow-injection CL method has been developed. The optimum chemical conditions for the CL reaction were investigated. Results Under the optimized conditions (KIO_ 4 concentration: 1.0×10 -5 mol/L; NaOH concentration: 0.1 mol/L; luminol concentration: 1.0×10 -4mol/L), tetracycline and oxytetracycline were determined. The linear range of the working curves was 1.0×10 -7 - 1.0×10 -4g/mL, the detection limits was 1.0×10 -8g/mL and 1.1×10 -8g/mL, and the relative standard deviation was 2.6% (C_S=1.0×10 -6g/mL; n=11) and 2.0% (C_S=1.0×10 -6g/mL; n=11) respectively. Conclusion The method is simple, rapid, and sensitive, and it has been successfully applied to the the determination of tetracycline and oxytetracycline tablets, the mean recoveries being 99.7% and 98.8% respectively.

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.

Flow Injection Chemiluminescence Determination of 4-methylsalicylic

As potassium bichromate can be reduced by 4-methysalicylic acid to chromium(III) which enhance the CL intensity of luminol-H2O2 system,a new chemiluminescence system for the determination of 4-methysalicylic acid has been established.The relative CL intensity was correlated with salicylic acid concentration in the range 7.0×10-9～8.0×10-6 mol/L,and the detection limit was 1.0×10-9 mol/L.The relative standard deviation(n=8) for 4.0×10-7 mol/L 4-methysalicylic acid is 2.9%.The method has been applied to the determination of 4-methysalicylic acid in the bactericidal solutions with satisfactory results.

Flow-injection Chemiluminescence Determination of Trace Calf Thymus DNA

A flow injection procedure for the determination of calf thymus DMA （CT DNA） over the range 2.1x10-6;.1x10-1 B.g mL-1 is described, based on measurement of the enhanced chemiluminescence emission of rhodamine B-Ce（IV） system, activated by imidazole-HCl buffer solution. This method is highly sensitive, with the linearity range broadened to five orders of magnitude. It has been applied to determine CT DNA in synthetic sample with satisfactory results.

SELECTIVE SULFUR DIOXIDE DETERMINATION BY GAS DIFFUSION FLOW INJECTION ANALYSIS WITH CHEMILUMINESCENT DETECTION

Sulfur dioxide has been found to decrease the chemiluminescence of luminol-iodine system.A new determination method for sulfur dioxide in atmosphere is developed by applying this reaction to a flow injection gas diffusion separation system.This permits the determination of sulfur dioxide selectively and rapidly.

Luminol-K_3Fe(CN)_6 chemiluminescence system for the determination of glipizide

A rapid and sensitive flow-injection chemiluminescence（CL） method for the determination of glipizide was developed on the basis of finding that glipizide can enhance the CL intensity of the luminol-K3Fe（CN）6 system.In optimum condition,the increased CL intensity was directly proportional to the concentration of glipizide in the range from 4.0×108 g/mL to 1.0×106 g/mL and the detection limit was 1.0×108 g/mL glipizide.The relative standard deviation（RSD） of the developed method was 2.1% with 11 repeated measurements of 1.0×107 g/mL glipizide.The developed method has been successfully applied to the analysis of glipizide in its pharmaceutical preparations.