An Improved Spectrophotometric Method for Determination of Total 3-Methoxy-4-Hydroxyphenylglycol in Urine

[摘要] A clinically useful spectrophotometric method for the determination of 3-methoxy-4-hydroxyphenylglycol (MHPG) is presented. After treatment with barium chloride, the urine is hydrolyzed with Glusulase (β-glucuronidase and sulfatase).† The hydrolysate is passed through a column of Amberlite CG-4B‡ to remove any 3-methoxy-4-hydroxymandelic acid (MHMA) and the pH is adjusted to neutral. The MHPG is extracted with ethyl acetate and returned into potassium carbonate solution. Conversion of the MHPG to vanillin is accomplished with periodate and the vanillin is subsequently extracted with toluene and then potassium carbonate solution. The vanillin concentration is determined at 360 nm and 380 nm. The mean recovery of added MHPG standard was 54.9%. The mean daily excretion of MHPG in 23 samples from 10 normal subjects was 1.87 ± 0.6 mg (range 0.81-3.64). In 3 subjects with pheochromocytoma the excretion of MHPG was markedly elevated. There was an excellent correlation of the MHMA and MHPG excretion.

[学科分类] 过敏症与临床免疫学