Micellar electrokinetic chromathography after pre capillary enzyme assay for the determination of phosphatase activity in semiarid soil

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

BIOCHEMICAL ENGINEERING JOURNAL

Elsevier

Año: 2009 vol. 46 p. 121 - 125

1369-703X

AbstractInorganic phosphorous (P) is an essential plant nutrient that must be added to mostsoils to maintain plant growth and sustain crop yields. Phosphatases enzymes play amajor role in the processes of mineralization of organic P substrates. In the presentstudy we propose a precise and accurate method to determine the alkaline and acidphosphatase activity in soil using adenosine monophosphate (AMP) as a substrate. Theadenosine released by the enzymatic reaction was quantified by micellar electrokineticchromatography (MEKC) method. The background electrolyte (BGE) consisted in 20mM phosphate buffer, 10 mM sodium dodecyl sulphate (SDS) and 10% acetonitrile(ACN). The LOD and LOQ for adenosine were 2.27 10-4 and 6.4 10-4 mg mL-1,respectively. This sensitive method allowed the use a natural compound as enzymaticsubstrate, which is commonly found in soil. Moreover, we improve the detectionmethod by diminishing the amount of waste and using a harmless substrate.