title: Application of response surface methodology for optimization of trace amount of diazinon preconcentration in natural waters and biological samples by carbon mesoporous CMK-3.
abstract: Preconcentration of trace amounts of diazinon by carbon mesoporous CMK-3 in water and biological samples and measurement by high-performance liquid chromatography were investigated. CMK-3 was prepared using hexagonal SBA-15 as the template. The synthesized materials were characterized by X-Ray diffraction (XRD), Fourier transform infrared spectroscopy, Brunaur-Emmet-Teller, transmission electron microscopy and Boehm titration method. The preconcentration procedure was optimized using a multivariate optimization approach following a two-stage process. The effect of analytical parameters including the amount of the CMK-3 as an adsorbent, pH, type and volume of eluent and flow rate of eluent and sample were studied by a screening project, then the effective parameters were optimized by response surface methodology based on central composite design. The average extraction efficiency of diazinon under optimal conditions (CMK-3 dosage = 25 mg, sample flow rate = 2.5 mL min-1, eluent flow rate = 1.25 mL min-1, volume of methanol as an eluent =3.5 mL and initial pH = 6) was 97.11%, which agrees well with the predicted response value (97.93%). The linearity of the method was in the range of 0.5-100 μg L-1with a correlation coefficient of 0.997. Enrichment factor, limit of detection and limit of quantification were 285.7, 0.09 and 0.23 μg L-1, respectively. The relative standard deviation (RSD) under optimum conditions was 2.21% (n = 5). The proposed method was applied to determine diazinon in real water and biological samples. Recovery of diazinon from real samples was between 95.80 and 104.94% with an RSD of 0.19-4.65%. Thus, this method is suitable for the preconcentration and determination of diazinon in real water and biological samples.
authors: Environmental Health Research Center, Golestan University of Medical Sciences, Gorgan, Iran.
authors: Somayeh
authors: S
authors: Beirami
authors: Environmental Health Research Center, Golestan University of Medical Sciences, Gorgan, Iran and Environmental Health Engineering Department, Hamedan University of Medical Science, Hamedan, Iran.
authors: Hadi Rahimzadeh
authors: HR
authors: Barzoki
authors: Department of Environmental Sciences, Faculty of Natural Resources, Tarbiat Modares University, Noor, Iran.
authors: Nader
authors: N
authors: Bahramifar
mesh_terms: D000327:Adsorption; D002244:Carbon / Q000737:chemistry; D002623:Chemistry Techniques, Analytical / Q000295:instrumentation / Q000379:methods*; D003976:Diazinon / Q000032:analysis* / Q000097:blood / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007492:Iran; D057230:Limit of Detection; D046529:Microscopy, Electron, Transmission; D009584:Nitrogen; D012822:Silicon Dioxide / Q000737:chemistry; D052616:Solid Phase Extraction / Q000379:methods; D017550:Spectroscopy, Fourier Transform Infrared; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: C509969:SBA-15; D014874:Water Pollutants, Chemical; D002244:Carbon; D012822:Silicon Dioxide; D009584:Nitrogen; D003976:Diazinon
keywords: biological sample; carbon mesoporous CMK-3; diazinon; high-performance liquid chromatography; preconcentration; response surface methodology