Some soft and mud samples have been determined for eadmiun, lead, copper,nickel and cobalt by atomic absorption speetrophotometry with a high-temperature graphite tube, after their extraction with sodium diethylthioca...Some soft and mud samples have been determined for eadmiun, lead, copper,nickel and cobalt by atomic absorption speetrophotometry with a high-temperature graphite tube, after their extraction with sodium diethylthiocarbonate into methy lisolutyl ketone. The tests of the effects of acidity on extraction and interference have been also carried out and the optimum conditions have been obtained. In addition, experiments on recoveries by this procedure have been performed for the elements in ppb amount. The recovery of the metals added to soil samples is made in the same manner and the precision values are given in this paper. This method is considered as to be applicable to the determination of soil and mud samples for the above-mentioned elements, of which the concentration is higher than 1 ppb.展开更多
It is evident that active Zn, Cu, Mo and substituted Mn will be gradually inereasing with time after loess is reclaimed into Dazhai farmland. The effective content of Zn has shown a remarkeble inerease even after a pl...It is evident that active Zn, Cu, Mo and substituted Mn will be gradually inereasing with time after loess is reclaimed into Dazhai farmland. The effective content of Zn has shown a remarkeble inerease even after a planting season within a year's time.The effective contents of Zn, Cu, Mn Mo, B deerease from top to bottom in the soil sections in Dazhai farms. The reverse tendeney is only true for active Zn in Some newly built farm bloeks. This may be due to the deficient supply of Zn in the newly built Dashai fields, and, therefore, good results may be expected if Zn fertilizer is used in a proper way.展开更多
文摘Some soft and mud samples have been determined for eadmiun, lead, copper,nickel and cobalt by atomic absorption speetrophotometry with a high-temperature graphite tube, after their extraction with sodium diethylthiocarbonate into methy lisolutyl ketone. The tests of the effects of acidity on extraction and interference have been also carried out and the optimum conditions have been obtained. In addition, experiments on recoveries by this procedure have been performed for the elements in ppb amount. The recovery of the metals added to soil samples is made in the same manner and the precision values are given in this paper. This method is considered as to be applicable to the determination of soil and mud samples for the above-mentioned elements, of which the concentration is higher than 1 ppb.
文摘It is evident that active Zn, Cu, Mo and substituted Mn will be gradually inereasing with time after loess is reclaimed into Dazhai farmland. The effective content of Zn has shown a remarkeble inerease even after a planting season within a year's time.The effective contents of Zn, Cu, Mn Mo, B deerease from top to bottom in the soil sections in Dazhai farms. The reverse tendeney is only true for active Zn in Some newly built farm bloeks. This may be due to the deficient supply of Zn in the newly built Dashai fields, and, therefore, good results may be expected if Zn fertilizer is used in a proper way.
