A novel green analytical procedure for monitoring of azoxystrobin in water samples by a flow injection chemiluminescence method with off-line ultrasonic treatment

A novel validated simple derivatization liquid chromatographic method with diode array detection for the simultaneous determination of mancozeb, azoxystrobin and difenoconazole in pesticide dosage form

A novel, rapid and simple reverse-phase high performance liquid chromatography (RP-HPLC) method for the simultaneous determination of three pesticides - mancozeb, azoxystrobin and difenoconazole by derivatization with ethyl iodide is presented. Analysis was performed on a C18 column (Agilent Eclipse plus, 150 mm × 4.6 mm; 5 μ) with the mobile phase consisting of acetonitrile + methanol (90 + 10 v/v) - water (0.1% v/v trifluoroacetic acid) (60 : 40, v/v) pumped isocratically at a flow rate of 1.0 mL min^-1 and detection wavelength of 205 nm and 272 nm. The factors affecting the derivatization reaction and separation conditions were carefully evaluated and optimized. The method was linear over the concentration range of 3.50 mg L^-1 to 31.48 mg L^-1 for mancozeb, 0.32 mg L^-1 to 2.85 mg L^-1 for azoxystrobin and 0.32 mg L^-1 to 2.89 mg L^-1 for difenoconazole. The new method was successfully applied for the analysis of mancozeb, azoxystrobin and difenoconazole in the pesticide formulation with range recoveries of 99.46% to 100.76%, 99.07% to 101.09% and 98.59% to 101.59%, respectively. The present method is suitable and favorable for the simultaneous separation and analysis of tertiary mixture analytes on account of its sensitivity, rapidity and cost-effectiveness. In addition, it could have excellent application prospects for the simultaneous determination of all three pesticides in other formulated products.

A review of recent developments based on chemiluminescence detection systems for pesticides analysis

Chemiluminescence is one of the most coveted methods for sensitive determination of pesticides in food and environmental samples. To date, many methods have been developed for qualitative and quantitative analysis of pesticides, ranging from traditional to advanced methods. This study outlines the progress in the conventional and advanced analytical methods, coupled to a chemiluminescence detection system, that are employed for the determination of pesticides in food and environmental samples. Different analytical methods including chromatographic methods, flow-based systems, and paper-based systems are reviewed in this paper. As well, new advances in the application of nanomaterials, aptamer, and molecularly imprinted polymers are highlighted. We also address the challenges and difficulties associated with these methods. Finally, we highlight the future direction in this active field of research.

Flow analysis with chemiluminescence detection: Recent advances and applications

This article highlights the most important developments in flow analysis with chemiluminescence (CL) detection, describing different flow systems that are compatible with CL detection, detector designs, commonly applied CL reactions and approaches to sample treatment. Recent applications of flow analysis with CL detection (focusing on outputs published since 2010) are also presented. Applications are classified by sample matrix, covering foods and beverages, environmental matrices, pharmaceuticals and biological fluids. Comprehensive tables are provided for each area, listing the specific sample matrix, CL reaction used, linear range, limit of detection and sample treatment for each analyte. Finally, recent and emerging trends in the field are also discussed.

Evaluation of Pyridaben Residues on Fruit Surfaces and Their Stability by a Novel On-Line Dual-Frequency Ultrasonic Device and Chemiluminescence Detection

In this paper, we first report the development of a highly sensitive and economical method for accurate analysis of pyridaben residues on fruits based on dual-frequency ultrasonic treatment (DFUT) and flow injection chemiluminescence (CL) detection. The DFUT device is made by integrating an ultrasonic bath with an ultrasonic probe. Two quartz glass coils (QGC) with different structures have been designed and applied to evaluate the function of DFUT in the detection process. Recorded data showed that DFUT is an effective method for improving the pyridaben CL signal. The signal of pyridaben in response to DFUT is 2.0-3.3 times stronger than the response to only the ultrasonic probe at 20 kHz or the ultrasonic bath at 40 kHz. In addition, the response obtained from the concentric circle QGC is 2.1 times stronger than the response to the spiral tube QGC. Under the optimized condition, the proposed method has advantages, such as a wide linear range (0.8-100.0 μg L^-1), a high sensitivity (limit of detection of 0.085 μg L^-1), and good stability (RSDs ≤ 4.7% in the linear range) for pyridaben determination. We apply this method to monitor the residue pyridaben on some fruits. The data show that the maximum amounts of the residue on fruit surfaces after soaking in water (50 mg L^-1, 5 min) are 0.583 mg kg^-1 (apple), 0.794 mg kg^-1 (orange), and 0.351 mg kg^-1 (pear). However, the concentration of pyridaben in the presence of sunlight decreases rapidly, showing its poor light stability.

Flow-injection chemiluminescence method to detect a β2 adrenergic agonist

A new method for the detection of β2 adrenergic agonists was developed based on the chemiluminescence (CL) reaction of β2 adrenergic agonist with potassium ferricyanide-luminol CL. The effect of β2 adrenergic agonists including isoprenaline hydrochloride, salbutamol sulfate, terbutaline sulfate and ractopamine on the CL intensity of potassium ferricyanide-luminol was discovered. Detection of the β2 adrenergic agonist was carried out in a flow system. Using uniform design experimentation, the influence factors of CL were optimized. The optimal experimental conditions were 1 mmol/L of potassium ferricyanide, 10 µmol/L of luminol, 1.2 mmol/L of sodium hydroxide, a flow speed of 2.6 mL/min and a distance of 1.2 cm from 'Y2 ' to the flow cell. The linear ranges and limit of detection were 10-100 and 5 ng/mL for isoprenaline hydrochloride, 20-100 and 5 ng/mL for salbutamol sulfate, 8-200 and 1 ng/mL for terbutaline sulfate, 20-100 and 4 ng/mL for ractopamine, respectively. The proposed method allowed 200 injections/h with excellent repeatability and precision. It was successfully applied to the determination of three β2 adrenergic agonists in commercial pharmaceutical formulations with recoveries in the range of 96.8-98.5%. The possible CL reaction mechanism of potassium ferricyanide-luminol-β2 adrenergic agonist was discussed from the UV/vis spectra.

Luminol-based chemiluminescent signals: clinical and non-clinical application and future uses

Chemiluminescence (CL) is an important method for quantification and analysis of various macromolecules. A wide range of CL agents such as luminol, hydrogen peroxide, fluorescein, dioxetanes and derivatives of oxalate, and acridinium dyes are used according to their biological specificity and utility. This review describes the application of luminol chemiluminescence (LCL) in forensic, biomedical, and clinical sciences. LCL is a very useful detection method due to its selectivity, simplicity, low cost, and high sensitivity. LCL has a dynamic range of applications, including quantification and detection of macro and micromolecules such as proteins, carbohydrates, DNA, and RNA. Luminol-based methods are used in environmental monitoring as biosensors, in the pharmaceutical industry for cellular localization and as biological tracers, and in reporter gene-based assays and several other immunoassays. Here, we also provide information about different compounds that may enhance or inhibit the LCL along with the effect of pH and concentration on LCL. This review covers most of the significant information related to the applications of luminol in different fields.