本研究建立了微波消解-石墨炉原子吸收光谱测定果蔗镉的方法。果蔗样品经硝酸和过氧化氢消解,所得试液用超纯水定容稀释100 m L,在最佳工作条件下用石墨炉原子吸收法测定镉含量,镉质量浓度在0~1.0μg·L^(-1)以内与其对应的信号值...本研究建立了微波消解-石墨炉原子吸收光谱测定果蔗镉的方法。果蔗样品经硝酸和过氧化氢消解,所得试液用超纯水定容稀释100 m L,在最佳工作条件下用石墨炉原子吸收法测定镉含量,镉质量浓度在0~1.0μg·L^(-1)以内与其对应的信号值呈线性关系,相关系数为0.9994,方法的检出限(3s/k)为0.016μg·L^(-1),回收率为90.0%~108.6%;用标准物质进行对照,其测定值在给定的标准值范围之内。该方法具有简便、快速、安全、准确的特点,适合果蔗中的镉含量的测定。展开更多
Sea level observed by altimeter during the 1993-2007 period and the thermosteric sea level from 1945 through 2005 obtained by using the global ocean temperature data sets recently published are used to investigate the...Sea level observed by altimeter during the 1993-2007 period and the thermosteric sea level from 1945 through 2005 obtained by using the global ocean temperature data sets recently published are used to investigate the interannual and decadal variability of the sea level in the Japan/East Sea （JES） and its response to E1 Nifio and Southern Oscillation （ENSO）. Both the interannual variations of the sea level observed by altimeter and those of the thermosteric sea level obtained from reanalyzed data in the JES are closely related to ENSO. As a result, one important consequence is that the sea level trends are mainly caused by the thermal expansion in the JES. An ＇enigma＇ is revealed that the correlation between the thermosterie sea level and ENSO during the PDO （Pacific Decadal Oscillation） warm phase （post mid-1970s） is inconsistent with that during the cold phase （pre mid-1970s） in the JES. The thermosteric sea level trends and the Southern Oscillation Index （SOI） suggest a strong negative correlation during the period 1977-1998, whereas there appears a relatively weak positive correlation during the period 1945-1976 in the JES. Based on the SODA （Simple Oceanographic Data Assimilation） datasets, possible mechanisms of the interannual and decadal variability of the sea level in the JES are discussed. Comprehensive analysis reveals that the negative anomalies of SOI correspond to the positive anomalies of the southeast wind stress, the net advective heat flux and the sea level in the JES during the PDO warm phase. During the PDO cold phase, the negative anomalies of SOI correspond to the positive anomalies of the southwest wind stress, the negative anomalies of the net advective heat flux and the sea level in the JES.展开更多
[ Objective] The paper was to establish a quick detection method for residue of organphosphoras pesticides in chewing cane juices and provide guarantee for edible safety of chewing juice. [ Method] By using QuEChERS a...[ Objective] The paper was to establish a quick detection method for residue of organphosphoras pesticides in chewing cane juices and provide guarantee for edible safety of chewing juice. [ Method] By using QuEChERS and GC-NPD method, a rapid analysis method for residue of six kinds of organphosphorus pesti- cides （dichlorves, chlorpyrifos-methyl, malathion, fenthion, chlorpyrifos and triazophes） in sugarcane juices was established. [ Resdt] QuEChERS method was significantly superior to traditional extraction method and could extract six kinds of organphesphorus pesticides from chewing cane juices effectively, which gready saved organic reagent and time. Good linearity was found in different standard curves; when the concentration of pesticides was from 0. 020 toO. 100 rag/L, the re- covery rate was from 68.58% to 92.85%, and relative standard deviation （RSD） was ranged from 2.16% to 9.89%. [ Conclusion] The sensitivity, accuracy and precision of QuEChERS method were consistent with the technical requirements of pesticide residue determination. It not only could shorten sample processing cycle effectively, but also ensure that no impurity was in the sample peak and the recovery rate was also consistent with the requirements of residual analysis.展开更多
文摘本研究建立了微波消解-石墨炉原子吸收光谱测定果蔗镉的方法。果蔗样品经硝酸和过氧化氢消解,所得试液用超纯水定容稀释100 m L,在最佳工作条件下用石墨炉原子吸收法测定镉含量,镉质量浓度在0~1.0μg·L^(-1)以内与其对应的信号值呈线性关系,相关系数为0.9994,方法的检出限(3s/k)为0.016μg·L^(-1),回收率为90.0%~108.6%;用标准物质进行对照,其测定值在给定的标准值范围之内。该方法具有简便、快速、安全、准确的特点,适合果蔗中的镉含量的测定。
基金supported by the National Basic Research Program of China under Grant No. 973-2007CB- 411807
文摘Sea level observed by altimeter during the 1993-2007 period and the thermosteric sea level from 1945 through 2005 obtained by using the global ocean temperature data sets recently published are used to investigate the interannual and decadal variability of the sea level in the Japan/East Sea （JES） and its response to E1 Nifio and Southern Oscillation （ENSO）. Both the interannual variations of the sea level observed by altimeter and those of the thermosteric sea level obtained from reanalyzed data in the JES are closely related to ENSO. As a result, one important consequence is that the sea level trends are mainly caused by the thermal expansion in the JES. An ＇enigma＇ is revealed that the correlation between the thermosterie sea level and ENSO during the PDO （Pacific Decadal Oscillation） warm phase （post mid-1970s） is inconsistent with that during the cold phase （pre mid-1970s） in the JES. The thermosteric sea level trends and the Southern Oscillation Index （SOI） suggest a strong negative correlation during the period 1977-1998, whereas there appears a relatively weak positive correlation during the period 1945-1976 in the JES. Based on the SODA （Simple Oceanographic Data Assimilation） datasets, possible mechanisms of the interannual and decadal variability of the sea level in the JES are discussed. Comprehensive analysis reveals that the negative anomalies of SOI correspond to the positive anomalies of the southeast wind stress, the net advective heat flux and the sea level in the JES during the PDO warm phase. During the PDO cold phase, the negative anomalies of SOI correspond to the positive anomalies of the southwest wind stress, the negative anomalies of the net advective heat flux and the sea level in the JES.
基金Supported by Basic Scientific Research Special Project of Guangxi Academy of Agricultural Sciences(GNK2012YM11)Scientific Research and Technology Development Program of Nanning City(201102026B)+1 种基金Fundamental Research Project of Guangxi Academy of Agricultural Sciences(G2009001,201001G)Science and Technology Development Fund Project of Guangxi Academy of Agricultural Sciences(201002Z)
文摘[ Objective] The paper was to establish a quick detection method for residue of organphosphoras pesticides in chewing cane juices and provide guarantee for edible safety of chewing juice. [ Method] By using QuEChERS and GC-NPD method, a rapid analysis method for residue of six kinds of organphosphorus pesti- cides （dichlorves, chlorpyrifos-methyl, malathion, fenthion, chlorpyrifos and triazophes） in sugarcane juices was established. [ Resdt] QuEChERS method was significantly superior to traditional extraction method and could extract six kinds of organphesphorus pesticides from chewing cane juices effectively, which gready saved organic reagent and time. Good linearity was found in different standard curves; when the concentration of pesticides was from 0. 020 toO. 100 rag/L, the re- covery rate was from 68.58% to 92.85%, and relative standard deviation （RSD） was ranged from 2.16% to 9.89%. [ Conclusion] The sensitivity, accuracy and precision of QuEChERS method were consistent with the technical requirements of pesticide residue determination. It not only could shorten sample processing cycle effectively, but also ensure that no impurity was in the sample peak and the recovery rate was also consistent with the requirements of residual analysis.
