摘要
本文概述了吸光量的概念、原理、测试技术和一些应用实例。
Absorbability (Q) is a new concenpt which is derived
from absorbance of de-termining nitrate nitrogen in soil by UV spectrophotometry for
characterizing thecontents of nitrate nitrogen and soluble organic nitrogen in soils. Absorbance
indi-cates only the comcentration of a light-absorbing component in solution rather thanthe
content of this component in sample (e. g., soil sample). Absorbability maybe used as an index
of characterizing the content of a light-absorbing componentin sample.When a soil is extracted
by an extractant, the absorbability (Q) of the soil ata particular wave length is directly
proportional to the absorbance (A) and volume(V) of soil extract but inversely proportional to the
mass(m) of soil sample andthe optical path length (b),Soil-Q = AV/bmwithin a certain range, the
values of soil-Q possees additive property.The method of UV-absorbability is very simple,
rapid, inexpensive, sensitiveand precise, and the results obtained are reliable. The results of
our experimentshave shown that the soil absorbability values of total nitrogen, nitrate nitrogen,
andsoluble organic nitrogen (soil-Q_T, -Q_(NO_3), and -Q_(OM).) extracted by
electro-ultrafiltra-tion, 0.o1mol/L CaCl_2, and 0.01 or 0.05mol/L NaHCO_3 are closely correlated
withthe content of extractable total nitrogen, nitrate nitrogen, and organic nitrogen
(N_T,N_(NO_3), and N_(org)) determined by the Kjeldahi method or Technicon Autoanalyzer
Te-chniqe, UV spectrophotometry or phenol disulphonic method, and Technicon Auto-analyzer
techniqs, respectively, Therefore, the soil-Q values can really characterizethe content of
different fractions of available nitrogen in soil. Although soil-Qvalues are provided with relative
sense, the content of different forms of nitrogenin soil can be calculated by means of
regression equation of these two variables.S
出处
《土壤学报》
CAS
CSCD
北大核心
1995年第4期383-387,共5页
Acta Pedologica Sinica
关键词
吸光度
吸光量
紫外光谱法
土壤
硝态氮
测定
Absorbance,
Absorbability, UV spectrophtometry, Soil availablenitrogen
