Taste and odor （T＆O） problems in drinking water frequently occur because of many compounds present in the water, of which trans-1,10-dimethyl-trans-9-decalol （geosrnin） and 2-methylisoborneol （MIB） are well-kno...Taste and odor （T＆O） problems in drinking water frequently occur because of many compounds present in the water, of which trans-1,10-dimethyl-trans-9-decalol （geosrnin） and 2-methylisoborneol （MIB） are well-known. In this study, a fast and effective method was established for simultaneous determination of 10 T＆O compounds, including geosmin, MIB, 2,4,6-trichloroanisole （TCA）, 2-methylbenzofuran, 2-isopropyl-3-methoxypyrazine （IPMP）, 2-isobutyl-3-methoxypyrazine （IBMP）, cis-3-hexenyl acetate, trans,trans-2,4-heptadienal, trans, cis-2,6-nonadienal, and trans-2-decenal in water samples by headspace solid-phase microextraction （SPME） coupled with gas chromatography-mass spectrometry. An orthogonal array experimental design was used to optimize the effects of SPME fiber, extraction temperature, stirring rate, NaC1 content, extraction time, and desorption time. The limits of detection ranged from 0.1 to 73 ng/L were lower than or close to the odor threshold concentrations （OTCs）. All the 10 T＆O compounds were detected in the 14 water samples including surface water, treatment process water and tap water, taken from a waterworks in Lianyungang City, China. MIB and geosmin were detected in most samples at low concentration. Six T＆O compounds （IPMP, IBMP, trans,cis-2,6-nonadienal, 2-methylbenzofuran, trans-2-decenal, and TCA） were effectively decreased in water treatment process （sedimentation and filtration） that is different from cis-3-hexenyl acetate, MIB and geosmin. It is noted that the TCA concentrations at 15.9-122.3 ng/L and the trans,cis-2,6-nonadienal concentrations at 79.9-190.1 ng/L were over 10 times higher than their OTCs in tap water. The variation of the analytes in the all water samples, especially distribution system indicated that distribution system cannot be ignored as a T＆O compounds source.展开更多
A wide range of compounds with various structural features can cause taste and odor(T&O)problems in drinking water. It would be desirable to determine all of these compounds using a simple analytical method. In th...A wide range of compounds with various structural features can cause taste and odor(T&O)problems in drinking water. It would be desirable to determine all of these compounds using a simple analytical method. In this paper, a sensitive method combining liquid–liquid extraction(LLE) with gas chromatography-triple quadrupole tandem mass spectrometry(GC–MS/MS)was established to simultaneously analyze 51 odor-causing compounds in drinking water,including organic sulfides, aldehydes, benzenes, phenols, ethers, esters, ketones, nitrogenous heterocyclic compounds, 2-methylisoborneol and geosmin. Three deuterated analogs of target analytes, dimethyl disulfide-d6, benzaldehyde-d6 and o-cresol-3,4,5,6-d4,were used to correct the variations in recovery, and five isotope-labeled internal standards(4-chlorotoluene-d4, 1, 4-dichlorobenzene-d4, naphthalene-d8, acenaphthene-d10, phenanthrene-d10 respectively) were used prior to analysis to correct the variations arising from instrument fluctuations and injection errors. The calibration curves of the target compounds showed good linearity(R2> 0.99, level = 7),and method detection limits(MDLs) below 1/10 of the odor threshold concentrations were achieved for most of the odorants(0.10–20.55 ng/L). The average recoveries of most of the analytes in tap water samples were between 70% and 120%, and the method was reproducible(RSD < 20%, n = 7). Additionally, concentrations of odor-causing compounds in water samples collected from three drinking water treatment plants(DWTPs) were analyzed by this method.According to the results, dimethyl trisulfide, dimethyl disulfide and indole were considered to be the key odorants responsible for the swampy/septic odor. 2-Methylisoborneol and geosmin were detected as the main odor-causing compounds for musty/earthy odor in DWTP B.展开更多
Chlorine dioxide composite disinfectant generator that produces a mixture of the oxidant gases comprising chlorine dioxide, chlorine, ozone and hydrogen peroxide through electrolyzing salt,is widely utilized in China ...Chlorine dioxide composite disinfectant generator that produces a mixture of the oxidant gases comprising chlorine dioxide, chlorine, ozone and hydrogen peroxide through electrolyzing salt,is widely utilized in China presently.The experiments in the paper focused on the removal of benzene homologous compounds such as styrene, methyl and dimethyl benzene. The results indicated that pH value was the most crucial factor to influence the treatment effects while reaction time and input way were considered as the importance. The removal rate for benzene could reach 60% when above 80% for methyl, and 100% for styrene and dimethyl. The variation mechanisms between chlorine dioxide,chlorite and chloride which determine the drinking water quality also discussed.展开更多
Organic matters in drinking water of Kaschin-Beck disease areas were extracted. Then analyses and characterization were performed by means of multiply chemical and physical methods. The results did not show the obviou...Organic matters in drinking water of Kaschin-Beck disease areas were extracted. Then analyses and characterization were performed by means of multiply chemical and physical methods. The results did not show the obvious difference in the frame structure of humic substances and the structure of rmcromolecular compounds in the drinking water of disease and non-disease areas, but the difference in the contents of some micromolecular compounds and radicals. The investigation also includes the preliminary research on the photoreaction of drinking water from disease and non-disease areas and the accumulation of natural organic matter in the bone of tested animals.展开更多
目的建立顶空-固相微萃取(headspace solid-phase microextraction,HS-SPME)气相色谱串联质谱法(gas chromatography-tandem mass spectrometry,GC-MS/MS)测定饮水中包括2-异丙基-3-甲氧基吡嗪(IPMB)、2-异丁基-3-甲氧基吡嗪(IBMB)、二...目的建立顶空-固相微萃取(headspace solid-phase microextraction,HS-SPME)气相色谱串联质谱法(gas chromatography-tandem mass spectrometry,GC-MS/MS)测定饮水中包括2-异丙基-3-甲氧基吡嗪(IPMB)、2-异丁基-3-甲氧基吡嗪(IBMB)、二甲基异莰醇(2-MIB)、2,4,6-三氯苯甲醚(2,4,6-TCA)、2,3,6-三氯苯甲醚(2,3,6-TCA)、土臭素(GSM)和2,3,4-三氯苯甲醚(2,3,4-TCA)在内7种异味物质含量的检测方法。方法通过优化含盐量、萃取温度和时间、解析时间和温度、气相条件和质谱条件,实现饮水中上述7种异味物质的分析。结果7种异味物质的线性范围为0.50~100 ng/L,相关系数(R^(2))在0.9971~0.9990之间,检出限(limits of detection,LOD)和定量限(limits of quantitation,LOQ)范围分别为0.04~0.15 ng/L和0.14~0.50 ng/L,三个浓度水平(1.00、10.0和50.0 ng/L)加标平均回收率分别为85.0%~119%、103%~116%和92.3%~107%,相对标准偏差(n=6)分别为6.58%~14.1%、3.87%~9.01%和1.86%~8.98%。结论本方法操作、简便,选择性好、灵敏度高、准确度好,可用于饮水中7种异味物质的检测。展开更多
目的:研究小米油与大豆蛋白复合饮料的降血脂作用。方法:观察高脂模型大鼠饮用不同剂量的小米油复合饮料后的血脂水平变化。结果:与模型组2相比,在小米油复合饮料的三个剂量中,高剂量(1.5 m L/100 g·d)的降脂作用最佳,血清甘油三酯...目的:研究小米油与大豆蛋白复合饮料的降血脂作用。方法:观察高脂模型大鼠饮用不同剂量的小米油复合饮料后的血脂水平变化。结果:与模型组2相比,在小米油复合饮料的三个剂量中,高剂量(1.5 m L/100 g·d)的降脂作用最佳,血清甘油三酯(TG)和胆固醇(TC)均极显著降低(p<0.01),高密度脂蛋白胆固醇(HDL-C)显著升高(p<0.05);中剂量(0.75 m L/100 g·d)组的TC极显著降低(p<0.01)、TG显著降低和HDL-C显著升高(p<0.05);低剂量(0.30 m L/100 g·d)组的TC虽显著降低(p<0.05),但TG和HDL-C变化不显著,降血脂效果较差。结论:该小米油复合饮料在一定剂量范围内有较好的降血脂作用。展开更多
基金supported by the National Natural Science Foundation of China(No.21007077,51290283)the Ministry of Water Resources’ Special Funds for Scientific Research on Public Causes(No.201201032)
文摘Taste and odor （T＆O） problems in drinking water frequently occur because of many compounds present in the water, of which trans-1,10-dimethyl-trans-9-decalol （geosrnin） and 2-methylisoborneol （MIB） are well-known. In this study, a fast and effective method was established for simultaneous determination of 10 T＆O compounds, including geosmin, MIB, 2,4,6-trichloroanisole （TCA）, 2-methylbenzofuran, 2-isopropyl-3-methoxypyrazine （IPMP）, 2-isobutyl-3-methoxypyrazine （IBMP）, cis-3-hexenyl acetate, trans,trans-2,4-heptadienal, trans, cis-2,6-nonadienal, and trans-2-decenal in water samples by headspace solid-phase microextraction （SPME） coupled with gas chromatography-mass spectrometry. An orthogonal array experimental design was used to optimize the effects of SPME fiber, extraction temperature, stirring rate, NaC1 content, extraction time, and desorption time. The limits of detection ranged from 0.1 to 73 ng/L were lower than or close to the odor threshold concentrations （OTCs）. All the 10 T＆O compounds were detected in the 14 water samples including surface water, treatment process water and tap water, taken from a waterworks in Lianyungang City, China. MIB and geosmin were detected in most samples at low concentration. Six T＆O compounds （IPMP, IBMP, trans,cis-2,6-nonadienal, 2-methylbenzofuran, trans-2-decenal, and TCA） were effectively decreased in water treatment process （sedimentation and filtration） that is different from cis-3-hexenyl acetate, MIB and geosmin. It is noted that the TCA concentrations at 15.9-122.3 ng/L and the trans,cis-2,6-nonadienal concentrations at 79.9-190.1 ng/L were over 10 times higher than their OTCs in tap water. The variation of the analytes in the all water samples, especially distribution system indicated that distribution system cannot be ignored as a T＆O compounds source.
基金supported by the Major Science and Technology Program for Water Pollution Control and Treatment(Nos.2015ZX07406001 and 2017ZX07207004)the National Natural Science Foundation of China(Nos.51778602 and 21707117)the Major Project of Key Laboratory of Drinking Water Science and Technology,Research Center for EcoEnvironmental Sciences,CAS(No.17Z02KLDWST)
文摘A wide range of compounds with various structural features can cause taste and odor(T&O)problems in drinking water. It would be desirable to determine all of these compounds using a simple analytical method. In this paper, a sensitive method combining liquid–liquid extraction(LLE) with gas chromatography-triple quadrupole tandem mass spectrometry(GC–MS/MS)was established to simultaneously analyze 51 odor-causing compounds in drinking water,including organic sulfides, aldehydes, benzenes, phenols, ethers, esters, ketones, nitrogenous heterocyclic compounds, 2-methylisoborneol and geosmin. Three deuterated analogs of target analytes, dimethyl disulfide-d6, benzaldehyde-d6 and o-cresol-3,4,5,6-d4,were used to correct the variations in recovery, and five isotope-labeled internal standards(4-chlorotoluene-d4, 1, 4-dichlorobenzene-d4, naphthalene-d8, acenaphthene-d10, phenanthrene-d10 respectively) were used prior to analysis to correct the variations arising from instrument fluctuations and injection errors. The calibration curves of the target compounds showed good linearity(R2> 0.99, level = 7),and method detection limits(MDLs) below 1/10 of the odor threshold concentrations were achieved for most of the odorants(0.10–20.55 ng/L). The average recoveries of most of the analytes in tap water samples were between 70% and 120%, and the method was reproducible(RSD < 20%, n = 7). Additionally, concentrations of odor-causing compounds in water samples collected from three drinking water treatment plants(DWTPs) were analyzed by this method.According to the results, dimethyl trisulfide, dimethyl disulfide and indole were considered to be the key odorants responsible for the swampy/septic odor. 2-Methylisoborneol and geosmin were detected as the main odor-causing compounds for musty/earthy odor in DWTP B.
文摘Chlorine dioxide composite disinfectant generator that produces a mixture of the oxidant gases comprising chlorine dioxide, chlorine, ozone and hydrogen peroxide through electrolyzing salt,is widely utilized in China presently.The experiments in the paper focused on the removal of benzene homologous compounds such as styrene, methyl and dimethyl benzene. The results indicated that pH value was the most crucial factor to influence the treatment effects while reaction time and input way were considered as the importance. The removal rate for benzene could reach 60% when above 80% for methyl, and 100% for styrene and dimethyl. The variation mechanisms between chlorine dioxide,chlorite and chloride which determine the drinking water quality also discussed.
文摘Organic matters in drinking water of Kaschin-Beck disease areas were extracted. Then analyses and characterization were performed by means of multiply chemical and physical methods. The results did not show the obvious difference in the frame structure of humic substances and the structure of rmcromolecular compounds in the drinking water of disease and non-disease areas, but the difference in the contents of some micromolecular compounds and radicals. The investigation also includes the preliminary research on the photoreaction of drinking water from disease and non-disease areas and the accumulation of natural organic matter in the bone of tested animals.
文摘目的建立顶空-固相微萃取(headspace solid-phase microextraction,HS-SPME)气相色谱串联质谱法(gas chromatography-tandem mass spectrometry,GC-MS/MS)测定饮水中包括2-异丙基-3-甲氧基吡嗪(IPMB)、2-异丁基-3-甲氧基吡嗪(IBMB)、二甲基异莰醇(2-MIB)、2,4,6-三氯苯甲醚(2,4,6-TCA)、2,3,6-三氯苯甲醚(2,3,6-TCA)、土臭素(GSM)和2,3,4-三氯苯甲醚(2,3,4-TCA)在内7种异味物质含量的检测方法。方法通过优化含盐量、萃取温度和时间、解析时间和温度、气相条件和质谱条件,实现饮水中上述7种异味物质的分析。结果7种异味物质的线性范围为0.50~100 ng/L,相关系数(R^(2))在0.9971~0.9990之间,检出限(limits of detection,LOD)和定量限(limits of quantitation,LOQ)范围分别为0.04~0.15 ng/L和0.14~0.50 ng/L,三个浓度水平(1.00、10.0和50.0 ng/L)加标平均回收率分别为85.0%~119%、103%~116%和92.3%~107%,相对标准偏差(n=6)分别为6.58%~14.1%、3.87%~9.01%和1.86%~8.98%。结论本方法操作、简便,选择性好、灵敏度高、准确度好,可用于饮水中7种异味物质的检测。
文摘目的:研究小米油与大豆蛋白复合饮料的降血脂作用。方法:观察高脂模型大鼠饮用不同剂量的小米油复合饮料后的血脂水平变化。结果:与模型组2相比,在小米油复合饮料的三个剂量中,高剂量(1.5 m L/100 g·d)的降脂作用最佳,血清甘油三酯(TG)和胆固醇(TC)均极显著降低(p<0.01),高密度脂蛋白胆固醇(HDL-C)显著升高(p<0.05);中剂量(0.75 m L/100 g·d)组的TC极显著降低(p<0.01)、TG显著降低和HDL-C显著升高(p<0.05);低剂量(0.30 m L/100 g·d)组的TC虽显著降低(p<0.05),但TG和HDL-C变化不显著,降血脂效果较差。结论:该小米油复合饮料在一定剂量范围内有较好的降血脂作用。
