%0 Journal Article
%T Efici¨ºncia da quantifica  o do carbono da biomassa microbiana por espectrofotometria comparada ao m¨¦todo titrim¨¦trico Quantification efficiency of the microbial biomass carbon by spectrophotometry assay as compared to the titrimetric method
%A Adriano M. Knupp
%A Enderson P. de B. Ferreira
%J Revista Brasileira de Ci¨ºncias Agr¨¢rias
%D 2011
%I Universidade Federal Rural de Pernambuco
%R 10.5039/agraria.v6i4a1071
%X Dentre os parametros de qualidade do solo, o carbono da biomassa microbiana (Cmic) ¨¦ um dos mais utilizados, por¨¦m, o processo de an¨¢lise mais adotado pelos laborat¨®rios promove a gera  o de res¨ªduos t¨®xicos. Com o objetivo de reduzir a gera  o de res¨ªduos no processo anal¨ªtico, foram realizados testes comparativos entre a titrimetria e a espectrofotometria para a quantifica  o do carbono microbiano, a partir de amostras de solo coletadas nas profundidades de 0-10 cm e 10-20 cm em tr¨ºs tipos de solo com caracter¨ªsticas qu¨ªmicas, f¨ªsicas e de manejo distintas. Os valores de Cmic encontrados nos tr¨ºs solos pelo m¨¦todo espectrofotom¨¦trico foram semelhantes aos valores encontrados pela titrimetria. Quando se utilizou a espectrofotometria, houve redu  o de 42% na concentra  o de dicromato de pot¨¢ssio para a nova formula  o da solu  o digestora e de cerca de 20% no tempo de execu  o da an¨¢lise, al¨¦m de redu  o no volume de res¨ªduos t¨®xicos gerado. De acordo com os resultados obtidos, o uso da espectrofotometria apresentou-se vantajoso do ponto de vista ambiental, al¨¦m de n o diferir estatisticamente do m¨¦todo titrim¨¦trico. Among the soil quality parameters, the microbial biomass carbon (Cmic) is one of the most used; however, in contrast to the ecological use of this parameter, the analysis process used for Cmic determination has a negative bias with regard to toxic waste generation. Aiming to reduce waste generation in the analytical process, comparative tests were performed between titrimetry and spectrophotometry for the quantification of microbial carbon from soil samples collected at 0-10 cm and 10-20 cm deep in three soil types with different chemical, physical and management characteristics. Results showed that the Cmic values found by spectrophometry in the three soil types were similar to the values found by titrimetry. When spectrophotometry was used the potassium dichromate concentration was reduced in 42% for the new formulation of the digesting solution. Also, time execution was reduced in 20%, followed by the reduction in the volume of toxic waste generated. According to these results, the spectrophotometry process showed to be environmentally advantageous, besides, it did not differ statistically from the titrimetry method.
%K Extra  o do carbono
%K indicadores biol¨®gicos
%K res¨ªduos t¨®xicos
%K Carbon extraction
%K biological indicators
%K toxic waste
%U http://www.agraria.pro.br/sistema/index.php?journal=agraria&page=article&op=view&path%5B%5D=agraria_v6i4a1071