A new chemiluminescence (CL) method, which based on enhancement effect of dobutamine hydrochloride on the CL intensity produced by potassium permanganate oxidation on luminol is proposed for the determination of dobutamine hydrochloride. Under optimized conditions, the response of CL on concentration of dobutamine hydrochloride is linear in the range 1.0×10~(-3)-0.5 μg/mL with a detection limit (3σ) of 5.0×10~(-4) μg/mL. Relative standard deviation (RSD) is 3.39% for 0.4 μg/mL dobutamine hydrochloride (n=11). The proposed method has been successfully applied to the determination of dobutamine hydrochloride in pharmaceutical preparations, plasma and urine samples with satisfactory results.
A hydride generation-atomic fluorescence spectrometric detection method has been developed for the determination of lead in wastewater.The concentrations of potassium ferricyanide,KBH4,sodium hydroxide,sodium oxalate and hydrochloric acid were optimized and satisfactory analysis conditions identified.Under the optimized experiment conditions,the atomic fluorescence intensity was in a linear relationship to lead concentration in the range of 0-100 mg/L with the detection limit(3σ) of 0.44 mg/L.The relative standard deviation was 1.6%(n=11) for 40 μg/L lead standard solution.The proposed method has been applied successfully to the analysis of lead in environmental wastewater samples.
Three-dimensional fluorescence technology has been found to have an unique potential application in characterization of natural water quality.According to the reported researches in recent ten years,a summary has been made on the application of three-dimensional fluorescence in characterization of the natural water quality.In the na-tural water,there are mainly six fluorescence peaks,namely,humic acid-like fluorescence peaks such as Peak A,Peak C,and Peak M;protein-like fluorescence peaks such as Peak B,Peak T1,and Peak T2.Three-dimensional fluorescence technique can distinguish water samples in different sources and reflect the effect of human activity,microbial activity and phytoplankton in natural water.Additionally,the environment factors,including pH,temperature,metal ions can also affect the fluorescence response.
Dispersive liquid-phase microextraction with solidification of floating organic drop (SFO–DLPME) is one of the most interesting sample preparation techniques developed in recent years. In this paper, a new, rapid, and efficient SFO–DLPME coupled with high-performance liquid chromatography (HPLC) was established for the extraction and sensitive detection of banned Sudan dyes, namely, Sudan I, Sudan II, Sudan III, and Sudan IV, in foodstuff and water samples. Various factors, such as the type and volume of extractants and dispersants, pH and volume of sample solution, extraction time and temperature, ion strength, and humic acid concentration, were investigated and optimized to achieve optimal extraction of Sudan dyes in one single step. After optimization of extraction conditions using 1-dodecanol as an extractant and ethanol as a dispersant, the developed procedure was applied for extraction of the target Sudan dyes from 2 g of food samples and 10 mL of the spiked water samples. Under the optimized conditions, all Sudan dyes could be easily extracted by the proposed SFO–DLPME method. Limits of detection of the four Sudan dyes obtained were 0.10–0.20 ng g–1 and 0.03 μg L–1 when 2 g of foodstuff samples and 10 mL of water samples were adopted, respectively. The inter- and intraday reproducibilities were below 4.8% for analysis of Sudan dyes in foodstuffs. The method was satisfactorily used for the detection of Sudan dyes, and the recoveries of the target for the spiked foodstuff and water samples ranged from 92.6 to 106.6% and from 91.1 to 108.6%, respectively. These results indicated that the proposed method is simple, rapid, sensitive, and suitable for the pre-concentration and detection of the target dyes in foodstuff samples.
For the first time, this article demonstrated that V2O5 nanowires served as a robust and efficient peroxidase mimic catalyst in luminol-based chemiluminescence reaction in aqueous media at high temperature. Over 90% of the maximum catalytic activity remained at 70 °C. Singlet oxygen was involved in the CL reaction catalysed by V2O5 nanowires, which was quite different from the traditional catalysts.
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