علوم غیرزیستی دریا
Zeynab Sepahvand; Mahmoud Nassiri; Rouholla Heydari; Sayyed Hossein Hashemi
Abstract
In this study, a sensitive and economical method is suggested for the rapid determination of formaldehyde in seawater samples. This method is based on the reaction of formaldehyde with 5, 5-di methyl-1, 3-cyclohexane dion (dimedone) in the presence of ammonium acetate. After the reaction of derivative, ...
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In this study, a sensitive and economical method is suggested for the rapid determination of formaldehyde in seawater samples. This method is based on the reaction of formaldehyde with 5, 5-di methyl-1, 3-cyclohexane dion (dimedone) in the presence of ammonium acetate. After the reaction of derivative, a mixture of 900 µL of ethanol as a dispersive solvent and 100 µL of chloroform as an extraction solvent was rapidly injected into a water sample containing formaldehyde. Their concentrations were determined spectrophotometrically in micro-cuvettes at 395 nm. Under the optimum conditions, the calibration graph was linear in the range of (0.1-100) µg/L with the detection limit of 0.02 µg/L and limit of quantification of 0.07 µg/L for formaldehyde. Parameters affecting extraction efficiency including pH, type and volume of extraction and disperser solvents, and amount of dimedone, were investigated and optimized. Under the optimum conditions, the linearity of the technique was in the range of 0.1-100.0 µg. L-1 with a detection limit of 0.02 µg. L-1 for the same compound. The relative recoveries of formaldehyde from seawater samples at spiking levels of 10 µg. L-1 were between 97.0-99.4%. The proposed method was successfully applied for the determination of formaldehyde in seawater of Chabahar Bay.
علوم غیرزیستی دریا
Mahmoud Nassiri; Morteza Ziyaadini; Kamalodin Kor
Abstract
Abstract:Environmental pollution imposes serious hazards and problems to the living organisms. This study aimed to determine the concentration and seasonal alteration of di-(2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DnBP) in the surface water of Chabahar Bay. Four replicated water samples ...
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Abstract:Environmental pollution imposes serious hazards and problems to the living organisms. This study aimed to determine the concentration and seasonal alteration of di-(2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DnBP) in the surface water of Chabahar Bay. Four replicated water samples were taken from the surface layers of seven stations in Chabahar Bay and prepared by dispersive liquid–liquid microextraction (DLLME) method, before being injected into the Gas Chromatography with flame ionization detector. In this method, 0.5 ml of methanol (as diffusion solvent) and 20 µl of carbon tetrachloride (as extraction solvent) were injected quickly into the sea water samples, and after extraction, the deposited phase was taken by a Hamilton syringe and injected into the GC equipment for measurement. Under the optimum extraction and experimental conditions, the method yields a linear calibration curve in the concentration range from 10 to 600 µg/L for target analytes. The enrichment factors for DEHP and DnBP were 775 and 790, the correlation factor 0.997 and 0.997, the limits of detection were 0.04 and 1.78 µg/L and the relative standard deviations of DEHP and DnBP were 0.0036 and 0.058, respectively.The results revealed that the concentration of DEHP and DnBP differ considerably at different stations. Significant differences were also observed between the concentration of DEHP and DnBP at various stations (P ≤ 0.05).