In this study, Ultra High Performance Electrospray Ionization Ion Trap Time of Flight Mass Spectrometry (UHPLC-ESI-1T-TOF MS) method is used to screen the polymer additives in drinking water that is stored in Polyet...In this study, Ultra High Performance Electrospray Ionization Ion Trap Time of Flight Mass Spectrometry (UHPLC-ESI-1T-TOF MS) method is used to screen the polymer additives in drinking water that is stored in Polyethylene Terephthalate (PET) bottles. After directly analyzing the commercially available water samples, 3 polymer additives (chimassorb 81, irgafos 168 and oleamide) were detected. However, after exposure to sunshine for 8 days, two additional polymer additives (antioxidant 2246 and Butylated Hydroxytoluene (BHT)) were detected besides the former three additives.展开更多
Concentrations of nitrate and trace elements such as arsenic,cadmium,chromium,copper,manganese,nickel,lead,selenium,antimony and mercury in 18 different brands of bottled water were investigated.For comparison,samples...Concentrations of nitrate and trace elements such as arsenic,cadmium,chromium,copper,manganese,nickel,lead,selenium,antimony and mercury in 18 different brands of bottled water were investigated.For comparison,samples of tap and well water from three different places of Tehran were also analyzed.UV/VIS spectrophotometer and Graphite Furnace Atomic Absorption Spectrometer were used for the analysis of nitrate and trace elements,respectively.Results obtained were compared to Iranian,World Health Organization(WHO)and Environmental Protection Agency(EPA)guideline for drinking water.Nitrate concentration in bottled,tap and well water samples were in maximum safe nitrate concentration of Iranian and WHO standards.However,70%of bottled water samples and one sample of tap water were below the standard level proposed by EPA and probably remedial action should be taken.Concentration levels of all analyzed elements investigated in all examined water samples were below the maximum contaminant level prescribed by Iranian,WHO and EPA regulations.展开更多
Strontium has four naturally occurring stable isotopes,84Sr,86Sr,87Sr,and 88Sr,with abundances of 0.56,9.87,approximately 7.04,and 82.53 atomic %,respectively.The 87Sr/86Sr isotope ratio is variable due to the additio...Strontium has four naturally occurring stable isotopes,84Sr,86Sr,87Sr,and 88Sr,with abundances of 0.56,9.87,approximately 7.04,and 82.53 atomic %,respectively.The 87Sr/86Sr isotope ratio is variable due to the addition of radiogenic 87Sr produced by the beta decay of 87Rb with a half-life of 4.88 ± 0.05 Ga.Thus,展开更多
文摘In this study, Ultra High Performance Electrospray Ionization Ion Trap Time of Flight Mass Spectrometry (UHPLC-ESI-1T-TOF MS) method is used to screen the polymer additives in drinking water that is stored in Polyethylene Terephthalate (PET) bottles. After directly analyzing the commercially available water samples, 3 polymer additives (chimassorb 81, irgafos 168 and oleamide) were detected. However, after exposure to sunshine for 8 days, two additional polymer additives (antioxidant 2246 and Butylated Hydroxytoluene (BHT)) were detected besides the former three additives.
文摘Concentrations of nitrate and trace elements such as arsenic,cadmium,chromium,copper,manganese,nickel,lead,selenium,antimony and mercury in 18 different brands of bottled water were investigated.For comparison,samples of tap and well water from three different places of Tehran were also analyzed.UV/VIS spectrophotometer and Graphite Furnace Atomic Absorption Spectrometer were used for the analysis of nitrate and trace elements,respectively.Results obtained were compared to Iranian,World Health Organization(WHO)and Environmental Protection Agency(EPA)guideline for drinking water.Nitrate concentration in bottled,tap and well water samples were in maximum safe nitrate concentration of Iranian and WHO standards.However,70%of bottled water samples and one sample of tap water were below the standard level proposed by EPA and probably remedial action should be taken.Concentration levels of all analyzed elements investigated in all examined water samples were below the maximum contaminant level prescribed by Iranian,WHO and EPA regulations.
文摘Strontium has four naturally occurring stable isotopes,84Sr,86Sr,87Sr,and 88Sr,with abundances of 0.56,9.87,approximately 7.04,and 82.53 atomic %,respectively.The 87Sr/86Sr isotope ratio is variable due to the addition of radiogenic 87Sr produced by the beta decay of 87Rb with a half-life of 4.88 ± 0.05 Ga.Thus,