Interference in Pisano’s Urinary Metanephrine Assay after Use of X-Ray Contrast Media

[摘要] Certain radiopaque dyes ("Renovist" and "Renografin") contain methylglucamine salts of diatrizoate, which interfere in the Pisano cationexchange method for measuring urinary metanephrine. Methylglucamine is adsorbed to the resin and eluted with the metanephrines. It then consumes the periodate, preventing oxidation of the metanephrines to vanillin and leading to falsely negative results. The methylglucamine can be separated from the metanephrines by adsorbing the metanephrines on QAE Sephadex A-25 acetate at pH 11.2.

[学科分类] 过敏症与临床免疫学