Determination of Free Urea in Fertilizers Containing Urea Formaldehyde Polymers
1977; Oxford University Press; Volume: 60; Issue: 3 Linguagem: Inglês
10.1093/jaoac/60.3.708
ISSN0004-5756
Autores Tópico(s)Advanced Chemical Sensor Technologies
ResumoAbstract This report describes a method for determining free, unreacted urea nitrogen in mixed compounds containing condensation products of urea and formaldehyde by using an ammonia gas-sensing electrode. Free urea is determined by potentiometrically measuring the ammonia produced following exhaustive hydrolysis by urease and subtracting the amount of ammonia present before enzymatic hydrolysis. Urea of condensed polymers does not interfere in free urea determination.
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