This chapter discusses the turbidimetric and nephelometric methods for the estimation of sulfate. Inorganic sulfate is the major end product of sulfur metabolism in higher animals and is excreted mainly via the kidney. Its determination in urine thus allows the assessment of the dietary intake of sulfur amino acids in animals and human beings. Methods currently favored are based on the precipitation of sulfate with barium ions, but the old gravimetric procedures that are insensitive and tedious have been superseded by turbidimetric or nephelometric methods as described in the chapter. Turbidimetric or nepheiometric procedures require that certain precautions be taken. They should be performed under acid conditions to avoid interference from phosphate and preformed barium sulfate, and a stabilizing agent should be present in the assay to obtain adequate precision. The turbidimetric procedure is convenient for biological samples containing very little protein but a relatively high concentration of sulfate as in samples of urine. The nephelometric procedure, on the other hand, involves a deproteinization step and is applicable to samples of lower concentrations of sulfate, such as serum or plasma. Series: Methods in Enzymology (Book 143) Hardcover: 582 pages Publisher: Academic Press; Language: English ISBN-10: 0121820432 ISBN-13: 978-0121820435 Product Dimensions: 6 x 9 inches Link Download http://nitroflare.com/view/6E9D9691080CC03https://drive.google.com/drive/folders/1yLBzZ1rSQoNjmWeJTZ3WGQHg04L1
