The ion chromatography combined solid phase extraction (SPE) method was developed for the analysis of low concentration haloacetic acids (HAAs), a class of disinfection by-products formed from chlorination of hosp...The ion chromatography combined solid phase extraction (SPE) method was developed for the analysis of low concentration haloacetic acids (HAAs), a class of disinfection by-products formed from chlorination of hospital wastewater. The monitored HAAs included monochloroacetic acid, monobromoacetic acid, dichloroacetic acid, dibromoacetic acid and trichloroacetic acid. The method employed a sodium hydroxide eluent at a flow rate of 0.8 ml/min, electrolytically generated gradients, and suppressed conductivity detection. To analyze the HAAs in real hospital wastewater samples, C18 pretreatment cartridge was utilized to reduce samples' turbidity. Preconcentration with SPE and matrix elimination with treatment cartridges were investigated and found to be able to obtain acceptable detection limits. Linearity, repeatability and detection limits of the above method were evaluated. The detection limits of monobromoacetic acid and dibromoacetic acid were 2.61 μg/L and 1.30 μg/L, respectively, and the other three acids are ranging from 0.48 to 0.82μg/L under 25-fold preconcentration. When the above optimization procedure was applied to three hospital wastewater samples with different treatment processes in Tianjin, it was found that the dichloroacetic acid was the major compound, and the growth ratios of the HAAs after disinfection by sodium hypochlorite were 91.28%, 63.61% and 79.50%, respectively.展开更多
In the present work, a novel analytical method was proposed for the determination of toluene diisocyanate (TDI) in syntheticrubber track by ion chromatography (IC) coupled with an ultraviolet detector setting at 2...In the present work, a novel analytical method was proposed for the determination of toluene diisocyanate (TDI) in syntheticrubber track by ion chromatography (IC) coupled with an ultraviolet detector setting at 212 nm. TDI can be hydrolyzed to toluene diamine (TDA) which can be separated by cation-exchange IC easily. The optimum IC separation was performed on an IonPac CS12A column (150 mm ×4.0 mm) using 20 mmol L^-1 sodium sulfate, 10 mmol L^-1 sulfuric acid and 10% acetonitrile as eluent. It was found that a higher signal response of TDA could be obtained under alkaline condition. A suppressor was used to change the acidic eluent into alkaline one. 0.8 mol L^-1 potassium hydroxide was chosen as the optimum regeneration eluent. With the added suppressor and regenerant, signal response was magnified by about 16 times and lower limit of detection (LOD, 0.13 μg L^-1) was obtained. Within-day relative standard deviation (R.S.D.) was less than 3.6%. The recoveries of TDI spiked in synthetic-rubber track samoles were 96.4-110.6%.展开更多
Combining the system of rapid collection of ambient particles and ion chromatography, the system of rapid collection of fine particles and ion chromatography (RCFP-IC) was established to automatically analyze on-lin...Combining the system of rapid collection of ambient particles and ion chromatography, the system of rapid collection of fine particles and ion chromatography (RCFP-IC) was established to automatically analyze on-line the concentrations of water-soluble ions in ambient particles. Here, the general scheme of RCFP-IC is described and its basic performance is tested. The detection limit of RCFP-IC for SO4^2-, NO3^-, NO2^-, Cl^- and F- is below 0.3μg m^-3. The collection efficiency of RCFP-IC increases rapidly with increasing sized particles. For particles larger than 300 nm, the collection efficiency approaches 100%. The precision of RCFP-IC is more than 90% over 28 repetitions. The response of RCFP-IC is very sensitive and no obvious cross-pollution is found during measurement. A comparison of RCFP-IC with an integrated filter measurement indicates that the measurement of RCFP-IC is comparable in both laboratory experiments and field observations. The results of the field experiment prove that RCFP-IC is an effective on-line monitoring system and is helpful in source apportionment and pollution episode monitoring.展开更多
In June 2006,a 20.12 m shallow ice core was recovered from an elevation of 5,040 m in the northern branch firn basin of No.12 Glacier,Great Snow Mountain,in the western part of Qilian Mountain,China.Isotopes(δ 18 O),...In June 2006,a 20.12 m shallow ice core was recovered from an elevation of 5,040 m in the northern branch firn basin of No.12 Glacier,Great Snow Mountain,in the western part of Qilian Mountain,China.Isotopes(δ 18 O),major soluble ions,and radionuclide(β-activity) measurements from the ice core revealed a 46-year record(1960-2006).In this paper,the method of sea-salt ion tracer,correlation analysis and trend analysis were used in this research to confirm the source of the chemical composition.The correlation analysis and HYSPLIT backward trajectory analysis suggests that atmospheric soluble dust species dominate the chemical signature.展开更多
The changes of plasmalemma permeability and some primary inorganic ions of Antarctic ice microalgae ( Chlamydomonas sp. ICE-L) in the low-temperature stress were examined. The plasmalemma of 1CE-L could maintain the...The changes of plasmalemma permeability and some primary inorganic ions of Antarctic ice microalgae ( Chlamydomonas sp. ICE-L) in the low-temperature stress were examined. The plasmalemma of 1CE-L could maintain the stability at the freezing condition of -6 ℃. That signifies that it could maintain the proper function of plasmalemma and stability of the intracellular environment during sea ice formation. The function of inorganic ions on low-temperature adaptation of ICE-L was investigated by using the X-ray microanalysis method. Low temperature (0 - -6 ℃ ) induces Ca^2 + concentration increment of cytoplasm, but after 24 h the content decrease quickly to normal value. As a matter of fact, Ca^2 + plays an important role as the second messenger in the low temperature adaptation of ICE-L. In addition, low temperature also influences on the other primary inorganic ions transfer and the cell maintains activity by keeping ratio balance among different ions. Above all, it is necessary for Antarctic ice microalgae to survive and breed by maintaining the stability of K^ + content and the balance of Na^ +/Cl^ -.展开更多
A chromatographic analysis method for determining inorganic anions and melamine in fertilizers was established using ion chromatography(IC).The fertilizer samples were extracted by ultrasonic method with 7 g/L trichlo...A chromatographic analysis method for determining inorganic anions and melamine in fertilizers was established using ion chromatography(IC).The fertilizer samples were extracted by ultrasonic method with 7 g/L trichloroacetic acid solution and centrifuged.The supernatant is purified by a solid phase extraction column.Then,the anions in the solution were purified using SH-AP-1(250 mm×4.0 mm)as a separation column,and measured by a suppressed conductivity detector;the melamine in the solution was separated using SH-CC-4(200 mm×4.0 mm)as a separation column and detected by a UV detector.The results show that the mass concentration of anions had a linear relationship with its peak area within a certain range,the linear correlation coefficient r of the standard curve was greater than 0.999,the recovery rate of spiked samples was 93.4%-104.4%,and the relative standard deviation(RSD)of the measured value(n=6)was less than 4%.Thus,this method is widely suitable for detection of anions and cations in a variety of fertilizer samples.展开更多
comb-shaped polynier (BM350) with oligo-oxyetliylene side chains of thetype-O (CH_2CH_2O )_7CH_3 was prepared from methyl vinyl ether /maleic anhydridecopolymer- Honiogeneous aniorplious polymer electrolyte cornplexes...comb-shaped polynier (BM350) with oligo-oxyetliylene side chains of thetype-O (CH_2CH_2O )_7CH_3 was prepared from methyl vinyl ether /maleic anhydridecopolymer- Honiogeneous aniorplious polymer electrolyte cornplexes were madefrom the conib polymer and LiCF_3SO_3 by solvent casting from acetone, and theirconductivities were nieasured as a function of temperature and salt concentration.Maxiniuni conductivity close to 5. 08 ×10 ̄(-5) Scm ̄(-1) was obtained at room tempera-tureancl at a [Li]/[EO] ratio of about 0. 12. The conductivity which displayednon-Arrheni us behaviour was analyzed using the Vogel-Tammann-Fulcher equationand interpreted on the basis of the configurational entropy model. The results ofmid-IR sliowed that the coortlination of Li ̄+ to side chains made the C-O-C bandbecome broader and shift sliglitly- X-ray photoelectron spectroscopy analysis indi-cated that the oxygen atonis in the two situations could coordinate to Li ̄+ and thiscoortlination resulted in the reduction of the electron orbit binding energy of F andS.展开更多
When water-ice grows into salt solutions ion species are excluded by the ice differentially due to non-identical solubility in the ice lattice. This causes an electrical potential across the interface during the ice g...When water-ice grows into salt solutions ion species are excluded by the ice differentially due to non-identical solubility in the ice lattice. This causes an electrical potential across the interface during the ice growth process, initially named the Workman Reynolds Freezing Potential, and may be one of the causes for lightning. However, by measuring the voltage between the ice and water, we have found that when tetrahydrofuran hydrate crystals are grown into salt solutions all ion species are excluded equally and the potential does not manifest. When considered together, this marked difference in ion exclusion scenarios may have ramifications for hydrate exploration because of the chlorine anomaly, which is often used as an indicator of the presence of hydrate reserves.展开更多
基金Project supported by the Hi-Tech Research and Development Program(863) of China (No. 2003AA601130).
文摘The ion chromatography combined solid phase extraction (SPE) method was developed for the analysis of low concentration haloacetic acids (HAAs), a class of disinfection by-products formed from chlorination of hospital wastewater. The monitored HAAs included monochloroacetic acid, monobromoacetic acid, dichloroacetic acid, dibromoacetic acid and trichloroacetic acid. The method employed a sodium hydroxide eluent at a flow rate of 0.8 ml/min, electrolytically generated gradients, and suppressed conductivity detection. To analyze the HAAs in real hospital wastewater samples, C18 pretreatment cartridge was utilized to reduce samples' turbidity. Preconcentration with SPE and matrix elimination with treatment cartridges were investigated and found to be able to obtain acceptable detection limits. Linearity, repeatability and detection limits of the above method were evaluated. The detection limits of monobromoacetic acid and dibromoacetic acid were 2.61 μg/L and 1.30 μg/L, respectively, and the other three acids are ranging from 0.48 to 0.82μg/L under 25-fold preconcentration. When the above optimization procedure was applied to three hospital wastewater samples with different treatment processes in Tianjin, it was found that the dichloroacetic acid was the major compound, and the growth ratios of the HAAs after disinfection by sodium hypochlorite were 91.28%, 63.61% and 79.50%, respectively.
基金supported by the National Natural Science Foundation of China(No.20775070)Zhejiang Provincial Natural Science Foundation of China(No.Y507252).
文摘In the present work, a novel analytical method was proposed for the determination of toluene diisocyanate (TDI) in syntheticrubber track by ion chromatography (IC) coupled with an ultraviolet detector setting at 212 nm. TDI can be hydrolyzed to toluene diamine (TDA) which can be separated by cation-exchange IC easily. The optimum IC separation was performed on an IonPac CS12A column (150 mm ×4.0 mm) using 20 mmol L^-1 sodium sulfate, 10 mmol L^-1 sulfuric acid and 10% acetonitrile as eluent. It was found that a higher signal response of TDA could be obtained under alkaline condition. A suppressor was used to change the acidic eluent into alkaline one. 0.8 mol L^-1 potassium hydroxide was chosen as the optimum regeneration eluent. With the added suppressor and regenerant, signal response was magnified by about 16 times and lower limit of detection (LOD, 0.13 μg L^-1) was obtained. Within-day relative standard deviation (R.S.D.) was less than 3.6%. The recoveries of TDI spiked in synthetic-rubber track samoles were 96.4-110.6%.
基金This work was supported by the National Natural Science Foundation of China under Grant No. 40525016.
文摘Combining the system of rapid collection of ambient particles and ion chromatography, the system of rapid collection of fine particles and ion chromatography (RCFP-IC) was established to automatically analyze on-line the concentrations of water-soluble ions in ambient particles. Here, the general scheme of RCFP-IC is described and its basic performance is tested. The detection limit of RCFP-IC for SO4^2-, NO3^-, NO2^-, Cl^- and F- is below 0.3μg m^-3. The collection efficiency of RCFP-IC increases rapidly with increasing sized particles. For particles larger than 300 nm, the collection efficiency approaches 100%. The precision of RCFP-IC is more than 90% over 28 repetitions. The response of RCFP-IC is very sensitive and no obvious cross-pollution is found during measurement. A comparison of RCFP-IC with an integrated filter measurement indicates that the measurement of RCFP-IC is comparable in both laboratory experiments and field observations. The results of the field experiment prove that RCFP-IC is an effective on-line monitoring system and is helpful in source apportionment and pollution episode monitoring.
基金supported by the National Basic Research Program of China (2007CB411501)the National Essential Scientific Program of the Ministry of Scienceand Technology of the People’s Republic of China(2006FY110200)
文摘In June 2006,a 20.12 m shallow ice core was recovered from an elevation of 5,040 m in the northern branch firn basin of No.12 Glacier,Great Snow Mountain,in the western part of Qilian Mountain,China.Isotopes(δ 18 O),major soluble ions,and radionuclide(β-activity) measurements from the ice core revealed a 46-year record(1960-2006).In this paper,the method of sea-salt ion tracer,correlation analysis and trend analysis were used in this research to confirm the source of the chemical composition.The correlation analysis and HYSPLIT backward trajectory analysis suggests that atmospheric soluble dust species dominate the chemical signature.
文摘The changes of plasmalemma permeability and some primary inorganic ions of Antarctic ice microalgae ( Chlamydomonas sp. ICE-L) in the low-temperature stress were examined. The plasmalemma of 1CE-L could maintain the stability at the freezing condition of -6 ℃. That signifies that it could maintain the proper function of plasmalemma and stability of the intracellular environment during sea ice formation. The function of inorganic ions on low-temperature adaptation of ICE-L was investigated by using the X-ray microanalysis method. Low temperature (0 - -6 ℃ ) induces Ca^2 + concentration increment of cytoplasm, but after 24 h the content decrease quickly to normal value. As a matter of fact, Ca^2 + plays an important role as the second messenger in the low temperature adaptation of ICE-L. In addition, low temperature also influences on the other primary inorganic ions transfer and the cell maintains activity by keeping ratio balance among different ions. Above all, it is necessary for Antarctic ice microalgae to survive and breed by maintaining the stability of K^ + content and the balance of Na^ +/Cl^ -.
文摘A chromatographic analysis method for determining inorganic anions and melamine in fertilizers was established using ion chromatography(IC).The fertilizer samples were extracted by ultrasonic method with 7 g/L trichloroacetic acid solution and centrifuged.The supernatant is purified by a solid phase extraction column.Then,the anions in the solution were purified using SH-AP-1(250 mm×4.0 mm)as a separation column,and measured by a suppressed conductivity detector;the melamine in the solution was separated using SH-CC-4(200 mm×4.0 mm)as a separation column and detected by a UV detector.The results show that the mass concentration of anions had a linear relationship with its peak area within a certain range,the linear correlation coefficient r of the standard curve was greater than 0.999,the recovery rate of spiked samples was 93.4%-104.4%,and the relative standard deviation(RSD)of the measured value(n=6)was less than 4%.Thus,this method is widely suitable for detection of anions and cations in a variety of fertilizer samples.
文摘comb-shaped polynier (BM350) with oligo-oxyetliylene side chains of thetype-O (CH_2CH_2O )_7CH_3 was prepared from methyl vinyl ether /maleic anhydridecopolymer- Honiogeneous aniorplious polymer electrolyte cornplexes were madefrom the conib polymer and LiCF_3SO_3 by solvent casting from acetone, and theirconductivities were nieasured as a function of temperature and salt concentration.Maxiniuni conductivity close to 5. 08 ×10 ̄(-5) Scm ̄(-1) was obtained at room tempera-tureancl at a [Li]/[EO] ratio of about 0. 12. The conductivity which displayednon-Arrheni us behaviour was analyzed using the Vogel-Tammann-Fulcher equationand interpreted on the basis of the configurational entropy model. The results ofmid-IR sliowed that the coortlination of Li ̄+ to side chains made the C-O-C bandbecome broader and shift sliglitly- X-ray photoelectron spectroscopy analysis indi-cated that the oxygen atonis in the two situations could coordinate to Li ̄+ and thiscoortlination resulted in the reduction of the electron orbit binding energy of F andS.
文摘When water-ice grows into salt solutions ion species are excluded by the ice differentially due to non-identical solubility in the ice lattice. This causes an electrical potential across the interface during the ice growth process, initially named the Workman Reynolds Freezing Potential, and may be one of the causes for lightning. However, by measuring the voltage between the ice and water, we have found that when tetrahydrofuran hydrate crystals are grown into salt solutions all ion species are excluded equally and the potential does not manifest. When considered together, this marked difference in ion exclusion scenarios may have ramifications for hydrate exploration because of the chlorine anomaly, which is often used as an indicator of the presence of hydrate reserves.