[Objective] A method for the determination of exchangeable Ca and Mg contents in tobacco growing area by atomic absorption spectrometry was established. [Method] Factors in the extraction process, sample weight, ammon...[Objective] A method for the determination of exchangeable Ca and Mg contents in tobacco growing area by atomic absorption spectrometry was established. [Method] Factors in the extraction process, sample weight, ammonium acetate volume, extraction time and strontium chloride volume were tested, and the stability, precision and accuracy of the method were also investigated. Meanwhile, samples at different pH values were determined by this method. [Result] The results showed that this method operation has simple operation with good stability and high precision. [Conclusion] This method could be applied to determine exchangeable Ca and Mg contents in tobacco growing area.展开更多
A method for determining calcium （Ca）, potassium （K）, magnesium （Mg） and iron （Fe） in four fish species was opti- mized and validated. It included microwave mineralization of the samples and subsequent quantif...A method for determining calcium （Ca）, potassium （K）, magnesium （Mg） and iron （Fe） in four fish species was opti- mized and validated. It included microwave mineralization of the samples and subsequent quantification by flame atomic absorption spectroscopy （FAAS） with Zeeman-effect background correction. Using HNO3 （65%） and H202 （33%） as extraction solutions, the optimal conditions of extraction were established as follows： 0.5 g of sample mass; microwave time program of 300 W/5 min and 600 W/5 min. The method was free of matrix interferences. The linear correlation coefficients were ≥0.9991, the recovery percentage of analytes was from 99.31% to 103.70% and the RSD （relative standard deviation） was lower than 2.06%. The detection limits obtained were 32.3, 43.2, 14.0 and 68.6ng mL^-1 for Ca, K, Mg and Fe in FAAS respectively. It is shown that the method is rapid, simple, sensitive and accurate. The method was applied to the studies of digestibility and measurement of these nutrients in samples of fish collected from Norway, Japan and China.展开更多
Objective: To investigate effect of electroacupuncture (EA) on serum copper, zinc, calcium and magnesium levels in the rat models of depression. Methods: Forty healthy SD male rats were divided into a normal group, a ...Objective: To investigate effect of electroacupuncture (EA) on serum copper, zinc, calcium and magnesium levels in the rat models of depression. Methods: Forty healthy SD male rats were divided into a normal group, a model group, an EA group, and a maprotiline group, 10 in each with completely random. The depression models were prepared with isolated chronic unpredictable stress method in the latter three groups. EA was given at Baihui (GV 20), Yintang (EX-HN3), Fenglong (ST 40), and Taichong (LR 3) in the EA group from the second day of modeling, once every other day, 15 min each time. The maprotiline group was administered intragastrically suspension of maprotiline (10 mg/kg), once each day. After treatment for 3 weeks, serum copper and zinc levels were detected with atomic absorption method, and the serum calcium with Arsenazo Ⅲ method and magnesium with MTB method. Results: Compared with the normal group, the serum copper level (3.90±1.20mmol/L) significantly increased and the serum zinc level (2.08±0.44mmol/L) significantly decreased in the model group (P<0.05). Compared with the model group, the serum copper level (2.62±1.03mmol/L) significantly decreased, the serum zinc level (2.55±0.38mmol/L) significantly increased (P<0.05), but the serum calcium and magnesium levels did not significantly change in the EA group and the maprotiline group. Conclusion: EA can regulate the change of copper and zinc levels in the body induced by depression, which is possibly one of mechanisms of effectively improving depression symptoms.展开更多
文摘[Objective] A method for the determination of exchangeable Ca and Mg contents in tobacco growing area by atomic absorption spectrometry was established. [Method] Factors in the extraction process, sample weight, ammonium acetate volume, extraction time and strontium chloride volume were tested, and the stability, precision and accuracy of the method were also investigated. Meanwhile, samples at different pH values were determined by this method. [Result] The results showed that this method operation has simple operation with good stability and high precision. [Conclusion] This method could be applied to determine exchangeable Ca and Mg contents in tobacco growing area.
文摘A method for determining calcium （Ca）, potassium （K）, magnesium （Mg） and iron （Fe） in four fish species was opti- mized and validated. It included microwave mineralization of the samples and subsequent quantification by flame atomic absorption spectroscopy （FAAS） with Zeeman-effect background correction. Using HNO3 （65%） and H202 （33%） as extraction solutions, the optimal conditions of extraction were established as follows： 0.5 g of sample mass; microwave time program of 300 W/5 min and 600 W/5 min. The method was free of matrix interferences. The linear correlation coefficients were ≥0.9991, the recovery percentage of analytes was from 99.31% to 103.70% and the RSD （relative standard deviation） was lower than 2.06%. The detection limits obtained were 32.3, 43.2, 14.0 and 68.6ng mL^-1 for Ca, K, Mg and Fe in FAAS respectively. It is shown that the method is rapid, simple, sensitive and accurate. The method was applied to the studies of digestibility and measurement of these nutrients in samples of fish collected from Norway, Japan and China.
基金supported by the International Classical CulturalAssociation (No. XDHT2009023A)
文摘Objective: To investigate effect of electroacupuncture (EA) on serum copper, zinc, calcium and magnesium levels in the rat models of depression. Methods: Forty healthy SD male rats were divided into a normal group, a model group, an EA group, and a maprotiline group, 10 in each with completely random. The depression models were prepared with isolated chronic unpredictable stress method in the latter three groups. EA was given at Baihui (GV 20), Yintang (EX-HN3), Fenglong (ST 40), and Taichong (LR 3) in the EA group from the second day of modeling, once every other day, 15 min each time. The maprotiline group was administered intragastrically suspension of maprotiline (10 mg/kg), once each day. After treatment for 3 weeks, serum copper and zinc levels were detected with atomic absorption method, and the serum calcium with Arsenazo Ⅲ method and magnesium with MTB method. Results: Compared with the normal group, the serum copper level (3.90±1.20mmol/L) significantly increased and the serum zinc level (2.08±0.44mmol/L) significantly decreased in the model group (P<0.05). Compared with the model group, the serum copper level (2.62±1.03mmol/L) significantly decreased, the serum zinc level (2.55±0.38mmol/L) significantly increased (P<0.05), but the serum calcium and magnesium levels did not significantly change in the EA group and the maprotiline group. Conclusion: EA can regulate the change of copper and zinc levels in the body induced by depression, which is possibly one of mechanisms of effectively improving depression symptoms.
