Experimental investigations were conducted in this study to explore the effect of magnetization on water sample properties and to envisage whether the effect is beneficial for mercury detection in a sample of water or...Experimental investigations were conducted in this study to explore the effect of magnetization on water sample properties and to envisage whether the effect is beneficial for mercury detection in a sample of water or not. Subjecting the water sample to 0.3 Tesla magnetic field for 14 hours led to instantaneous effects on the examined water properties, where a reduction in the values of pH （7%） and interfacial tension （0.2%） was observed, whereas an increase （8%） in water electrical conductivity was recorded. Similar behaviours with slight changes in trend were observed after storing the samples for six days, which indicates a creation of permanent effects. Other experiments were conducted to explore the impact of magnetizing water sample containing inorganic mercury prior to detection by emission spectroscopy. Samples were prepared with different mercury concentrations and derivatized by using tin chloride （SnCI2）. The generated mercury vapour species were transported with aid of carrier gas into a dielectric barrier discharge plasma atomizer, in which the mercury signal at 253.65 nm was recorded. The results have shown 3.5%-7.5% increase in the signal intensities recorded for the magnetized samples, mostly attributed to a reduction in the sample surface tension and other reasons, which facilitates analyte derivatization.展开更多
Radiation affects the environment and local human activity in any location of the earth＇s surface. Due to this fact, the aim of this study was to monitor the ionizing radiation and rain intensity using portable devic...Radiation affects the environment and local human activity in any location of the earth＇s surface. Due to this fact, the aim of this study was to monitor the ionizing radiation and rain intensity using portable devices. During May 23 to October 2, 2015, it was made measures the intensity of gamma radiation from 30 keV to 10.0 MeV at a height of 25 meters in Sao Jos6 dos Campos city, SP, Brazil. It was used a crystal of sodium iodide scintillator 3 - 3 inches coupled to a photomultiplier and associated electronic. The measurements were made continually with minute＇s interval throughout the period and it was monitored rain intensity every minute at the same height of the tower. In this job, it was possible to correlate rain-radiation and it was observed which gamma radiation has a directly proportional relationship with rain and visible frequency of 1 day.展开更多
Oleanolic acid （OA） and ursolic acid （UA） are isomeric tritcrpenes that are difficult to separate chromatographically. Studies have indicated that both OA and UA have antifertility properties in several livestock ...Oleanolic acid （OA） and ursolic acid （UA） are isomeric tritcrpenes that are difficult to separate chromatographically. Studies have indicated that both OA and UA have antifertility properties in several livestock species, suppressing attainment of puberty, gonad function and gamete production. Being able to determine the presence and quantity of the OA and UA in moringa and pawpaw seeds will allow for calculation of optimal inclusion levels of these acids in animal diets for antifertility-activity. The purpose of the study was thus to quantify the levels of OA and UA in Moringa and pawpaw seed powder by means of ultra-high performance liquid chromatography with electrospray ionization tandem mass spectrometry （UHPLC-ESI-MS/MS）. Only OA was detected in moringa seeds at a concentration level of 0.508 p.g/g ＋ 0.032 pg/g dry weight. UA and OA could not be detected in pawpaw seeds used in this study. The presence of OA in moringa seeds suggest that the seeds can be included in tilapia diets as a potential antifertility treatment to control precocious breeding in tilapia culture in small scale farming systems in Sub-Saharan Africa. Further studies are warranted to determine the levels of OA and UA composition in moringa seeds from other parts of the Sub-Saharan Africa （other than Zambia）.展开更多
Cadmium （Cd） concentrations in the water extracts of ten contaminated soils by arsenic （As） with various iron （Fe） contents were measured using inductively coupled plasma atomic emission spectrometry （ICP-AES）...Cadmium （Cd） concentrations in the water extracts of ten contaminated soils by arsenic （As） with various iron （Fe） contents were measured using inductively coupled plasma atomic emission spectrometry （ICP-AES） and electrothermal atomic absorption spectrometry （ETAAS）, Due to the potential spectral interferences of As and Fe in the quantification of Cd, two methods were used for the background compensation. The first method was based on the use of a deuterium lamp （BGCD2 mode）. The second one required a Cd hollow cathode lamp pulsated with a current for which the intensity varies in the course of time （BGCSR mode）. The results showed that the choices of the analytical technique and the method used for the background compensation depend on the Cd, As and Fe concentrations in the solution and the concentration ratios As/Cd or/and Fe/Cd. In comparison with the ICP-AES and the ETAAS in combination with the BGCD2 mode, it was shown that the high-speed self-reversal method （HSSR） was a more appropriate method to correct As and Fe spectral interferences during the Cd measurements. On the other hand, depending on the Cd concentration, it was established that no significant Fe interference occurred during the Cd determination even if Fe concentration was 50 mg/L, reflecting the efficiency of the HSSR method to overcome the Fe interferences in the determination of Cd concentration by ETAAS without any matrix modifier in water extracts.展开更多
文摘Experimental investigations were conducted in this study to explore the effect of magnetization on water sample properties and to envisage whether the effect is beneficial for mercury detection in a sample of water or not. Subjecting the water sample to 0.3 Tesla magnetic field for 14 hours led to instantaneous effects on the examined water properties, where a reduction in the values of pH （7%） and interfacial tension （0.2%） was observed, whereas an increase （8%） in water electrical conductivity was recorded. Similar behaviours with slight changes in trend were observed after storing the samples for six days, which indicates a creation of permanent effects. Other experiments were conducted to explore the impact of magnetizing water sample containing inorganic mercury prior to detection by emission spectroscopy. Samples were prepared with different mercury concentrations and derivatized by using tin chloride （SnCI2）. The generated mercury vapour species were transported with aid of carrier gas into a dielectric barrier discharge plasma atomizer, in which the mercury signal at 253.65 nm was recorded. The results have shown 3.5%-7.5% increase in the signal intensities recorded for the magnetized samples, mostly attributed to a reduction in the sample surface tension and other reasons, which facilitates analyte derivatization.
文摘Radiation affects the environment and local human activity in any location of the earth＇s surface. Due to this fact, the aim of this study was to monitor the ionizing radiation and rain intensity using portable devices. During May 23 to October 2, 2015, it was made measures the intensity of gamma radiation from 30 keV to 10.0 MeV at a height of 25 meters in Sao Jos6 dos Campos city, SP, Brazil. It was used a crystal of sodium iodide scintillator 3 - 3 inches coupled to a photomultiplier and associated electronic. The measurements were made continually with minute＇s interval throughout the period and it was monitored rain intensity every minute at the same height of the tower. In this job, it was possible to correlate rain-radiation and it was observed which gamma radiation has a directly proportional relationship with rain and visible frequency of 1 day.
文摘Oleanolic acid （OA） and ursolic acid （UA） are isomeric tritcrpenes that are difficult to separate chromatographically. Studies have indicated that both OA and UA have antifertility properties in several livestock species, suppressing attainment of puberty, gonad function and gamete production. Being able to determine the presence and quantity of the OA and UA in moringa and pawpaw seeds will allow for calculation of optimal inclusion levels of these acids in animal diets for antifertility-activity. The purpose of the study was thus to quantify the levels of OA and UA in Moringa and pawpaw seed powder by means of ultra-high performance liquid chromatography with electrospray ionization tandem mass spectrometry （UHPLC-ESI-MS/MS）. Only OA was detected in moringa seeds at a concentration level of 0.508 p.g/g ＋ 0.032 pg/g dry weight. UA and OA could not be detected in pawpaw seeds used in this study. The presence of OA in moringa seeds suggest that the seeds can be included in tilapia diets as a potential antifertility treatment to control precocious breeding in tilapia culture in small scale farming systems in Sub-Saharan Africa. Further studies are warranted to determine the levels of OA and UA composition in moringa seeds from other parts of the Sub-Saharan Africa （other than Zambia）.
文摘Cadmium （Cd） concentrations in the water extracts of ten contaminated soils by arsenic （As） with various iron （Fe） contents were measured using inductively coupled plasma atomic emission spectrometry （ICP-AES） and electrothermal atomic absorption spectrometry （ETAAS）, Due to the potential spectral interferences of As and Fe in the quantification of Cd, two methods were used for the background compensation. The first method was based on the use of a deuterium lamp （BGCD2 mode）. The second one required a Cd hollow cathode lamp pulsated with a current for which the intensity varies in the course of time （BGCSR mode）. The results showed that the choices of the analytical technique and the method used for the background compensation depend on the Cd, As and Fe concentrations in the solution and the concentration ratios As/Cd or/and Fe/Cd. In comparison with the ICP-AES and the ETAAS in combination with the BGCD2 mode, it was shown that the high-speed self-reversal method （HSSR） was a more appropriate method to correct As and Fe spectral interferences during the Cd measurements. On the other hand, depending on the Cd concentration, it was established that no significant Fe interference occurred during the Cd determination even if Fe concentration was 50 mg/L, reflecting the efficiency of the HSSR method to overcome the Fe interferences in the determination of Cd concentration by ETAAS without any matrix modifier in water extracts.
