Micellar electrokinetic chromatography after precapillary enzyme assay for the determination of phosphatase activity in semiarid soil

PATRICIA WANDA STEGE; GERMÁN ALEJANDRO MESSINA; LORENA L. SOMBRA; GUILLERMO BIANCHI; ROBERTO A. OLSINA

BIOCHEMICAL ENGINEERING JOURNAL

ELSEVIER SCIENCE SA

Año: 2009 vol. 46 p. 121 - 125

1369-703X

Inorganic phosphorous (P) is an essential plant nutrient that must be added to most soils to maintain plantgrowth and sustain crop yields. Phosphatase enzymes play amajor role in the processes of mineralizationof organic P substrates. In the present study we propose a precise and accurate method to determine thealkaline and acid phosphatase activity in soil using adenosine monophosphate (AMP) as a substrate. Theadenosine released by the enzymatic reaction was quantified by micellar electrokinetic chromatography(MEKC) method. The background electrolyte (BGE) consisted in 20mM phosphate buffer, 10mM sodiumdodecyl sulphate (SDS) and 10% acetonitrile (ACN). The LOD and LOQ for adenosine were 2.27×10−4and 6.4×10−4 mgmL−1, respectively. This sensitive method allowed the use of natural compound asenzymatic substrate, which is commonly found in soil. Moreover, we improve the detection method bydiminishing the amount of waste and using a harmless substrate.