ABSTRACT
Objective To develop a satisfactory and reliable method for simultaneous determination of seven cephalosporin antibiotics (cefadroxil,cephalexin,cefoperazone,cefuroxime,cefradine,ceftazidime and cefotaxime) in water samples using solidphase extraction and high performance liquid chromatography.Methods The detection and reference wavelengths were 254 and 270 nm,respectively.The analytes were separated within 20 min by a gradient elution program.The optimized pretreatment of water samples was as following:using hydrophilic-lipophilic balance HLB as SPE cartridges,adjusting pH to 3 and adding 3.0 g NaCl per 500 ml water sample.Results The linear range of the method was 0.05-5.00 mg/L for ceftazidime,cefotaxime and cefuroxime,0.10-10.00 mg/L for cefadroxil,cephalexin and cefradine,and 0.20-20.00mg/L for cefoperazone.The coefficients for the analytes were above 0.99 and the limits of determination were 0.05-0.39 ?g/L.The recoveries of seven cephalosporin antibiotics in purified water were 86.64%-105.28%,and its relative standard deviation were 2.61%-11.64%.Conclusion The method was sensitive,accurate and repeatable,it is applicable to the determination of the cephalosporin antibiotics in waters.
ABSTRACT
Objective To investigate the endocrine disrupting chemicals contamination in source water and tap water in a city and to provide the scientific data for the water quality inspection,management and water treatment.Methods Fifteen samples of source water and tap water were collected in April,2006 and February,2007.Extraction of potential EDCs from samples was performed in columns packed with XAD-4 resins by using solid-phase extraction(SPE).Each sample was dried under a gentle air stream for 1 h and eluted with a mixture of acetone(20 ml) and dichloromethane(40 ml) for 3 times.The extracts were collected into a glass flask,evaporated under a gentle air stream and suspended again in 0.5 ml dichloromethane.Gas chromatography-mass spectrometry(GC-MS) was used for quantitative or qualitative analysis of the organic pollutants and the optimum conditions were determined.Results Seventy-eight organic pollutants were identified from the water samples.Most of them were phthalates,hydrocarbon,phenol,and benzene.Phthalates were found in all samples.Among them,bis(2-ethylhexyl) phthalate(CAS# 117817),di-n-butyl phthalate(CAS# 84742),and pentachlorophenol(CAS# 87865) were regarded as suspected endocrine disrupting chemicals.The concentration of bis-(2-ethylhexyl) phthalate and di-n-butyl phthalate ranged 0.004 75-4.450 ?g/L and 0.002 25-2.39 ?g/L,respectively.The concentration of pentachlorophenol was 0.727 ?g/L.Conclusion The source water and tap water in this city has been seriously polluted by organic pollutants,the main endocrine disrupting chemicals detected in the present investigation are phthalates and pentachlorophenol and the related health effects remain to be studied.
ABSTRACT
The pharmaceuticals have been playing an important role in insuring human health and stockbreeding for decades. However incompletely absorbed pharmaceuticals will find their way into the wastewater in their original structure or metabolites. The ineffective operation of wastewater-treatment plants makes it possible that the widespread appearance of pharmaceuticals in the aquatic environment. The pharmaceuticals become the kind of "persistent" pollutants in the aquatic environment since they have been widely and continually used in daily life although their half-lives are relatively short. Their occurrences threaten the aquatic ecological safety and human’s health. In recent years, European and North American countries have focused on the research of pharmaceuticals in the aquatic environment, while the related reports are scarce in China. This article comprehensively analyzed and discussed the effects of pharmaceuticals pollution in the aquatic environment on aquatic organism and human health. It will present an important reference for future related research as well as establishing ecological risk assessment of pharmaceuticals in aquatic environment in China.