A limited number of FI-CL methods have been reported based on the use of the Cu(III) complex in aqueous phosphoric acid and sulfuric acid solutions for the determination of ofloxacin, levofloxacin and enrofloxacin in pharmaceutical preparations, urine and veterinary preparations with detection limits (S/N = 3) 2016 © The Japan Society for Analytical Chemistry † To whom correspondence should be addressed. E-mail: yaqoob2001@hotmail.com Chemiluminescence (CL) with a flow-injection method is reported for the determination of thiabendazole (TBZ) fungicide based on its enhancement effect on diperiodatocuprate(III) (DPC)-sulfuric acid-CL system. The calibration graph was linear in the concentration range of 1 -2000 μg L -1 (R 2 = 0.9999, n = 8) with a limit of detection (S/N = 3) of 0.3 μg L -1 . The injection throughput was 160 h -1 with relative standard deviations (RSD, n = 4) of 1.1 -2.9% in the concentration range studied. The experimental variables e.g., reagents concentrations, flow rates, sample volume, and PMT voltage were optimized, and the potential interferences were investigated individually. The method was successfully applied to the determination of TBZ in water samples showing good agreement and recovery in the range of 92 ± 2.2 -108 ± 3% (n = 3) using dispersive liquid-liquid micro-extraction (DLLME). The possible CL reaction mechanism for DPC-sulfuric acid-TBZ is also discussed.Keywords Flow injection analysis, DPC, chemiluminescence, thiabendazole, water samples

Occurrence and distribution of organochlorine pesticides (OCPs), organophosphate pesticides (OPPs), and pyrethroid pesticides (PYRs) residues in the leafy vegetables were analyzed together with the soil samples using gas chromatography-electron capture detector. Edible tissues of vegetables showed detectable residues of these compounds indicating the influence of the conventional farms and nearby organic farms. In the vegetables, the OCPs concentrations were recorded as nd-133.3 ng/g, OPPs as nd-200 ng/g, and PYRs as nd-33.3 ng/g. In the soil, the OCPs concentrations were recorded as nd-30.6 ng/g, OPPs as nd-26.6 ng/g, and for PYRs as nd-6.7 ng/g. Bioconcentration factor (BCF) was higher for the OPPs (0.3) than the OCPs and PYRs (1.1). The OCPs concentration in the vegetables decreased in the following order: spinach > celery > broccoli > cauliflower > cabbage > lettuce > mustard. For OPPs, the concentration decreased in the following order: cauliflower > spinach > celery > cabbage > broccoli > lettuce > mustard and for PYRs as spinach > celery > lettuce > cabbage > broccoli. Principal component analysis indicates that the sources of these pesticides are not the same, and the pesticide application on the vegetables depends on the type of crop. There is a significant positive correlation between OPPs and the soil (r = 0.65) as compared to OCPs and PYRs (r = 0.1) as the vegetables accumulated OPPs more efficiently than OCPs and PYRs.

This study developed a simple flow injection (FI) method based on diperiodatonickelate(IV)-sulfuric acid reaction using chemiluminescence (CL) detection for the determination of thiram (THI) fungicide in fresh water using quinine as the sensitizer. The possible mechanism of the CL reaction was described using UV-Vis. absorption and CL spectra. Experimental variables were optimized by applying a univariate approach, and a linear calibration curve was obtained in the range of 1.0 Â 10 À3 -2.0 mg L À1 (R 2 = 0.9994, n = 9) with a limit of detection of 5.0 Â 10 À4 mg L À1 (S/N = 3) and an injection throughput of 200 h À1 . This approach was successfully applied to determine THI in fresh water by using solid-phase extraction and achieved a good recovery rate of 94%-110% with a relative standard deviation of 1.9%-3.7% (n = 4). The results obtained were compared with the reported FI-CL and high-performance liquid chromatography-ultraviolet methods, and the three methods did not differ significantly at the 95% confidence limit.

Diperiodatoargentate(III) (DPA)/silver(III) complex, [Ag(HIO6)2] 5-, in sulfuric acid medium has been used to determine hyoscine butylbromide (HBB) by flow injection (FI) coupled with chemiluminescence (CL) detector. A linear standard curve between the CL intensity and concentration range from 0.005 to 20 mg L -1 was obtained. The determination coefficient (R 2 ), limit of detection (3s × blank), relative standard deviation (RSD) for 0.5 mg L -1 HBB and analytical throughput were 0.9992 (n = 8), 5 × 10 -4 mg L -1 , 1.5% (n = 10) and 160 injections h -1 , respectively. The developed method was applied for the determination of HBB in pharmaceutical formulations with recoveries from 92 ± 4 to 108 ± 3%. For comparison, a spectrophotometric method was used and the results obtained by both methods were in good agreement at a 95% confidence level. The effect of key chemical and physical variables (reagent concentration, flow rate, sample volume, PMT voltage) and interfering species (pharmaceutical excipients and inorganic ions) on the determination of HBB was examined. The possible CL mechanism of HBB on silver(III) complex in sulfuric acid medium was also discussed in brief.Keywords Chemiluminescence, flow injection analysis, silver(III) complex, hyoscine butylbromide, pharmaceutical formulations

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