Colorimetry of p-aminohippurate in the presence of sulfamethoxazole.
Colorimetric quantification of p-aminohippurate (PAH), which is helpful in assessment of renal function, is subject to interference from sulfa compounds such as sulfamethoxazole. We were unable to measure serum PAH in two patients receiving a trimethoprim-sulfamethoxazole combination because of interference by the latter with the colorimetric estimation. We found that isoamyl acetate removes sulfamethoxazole from the samples without influencing PAH. The extraction is simple, inexpensive, and reproducible.
Preuss
H G
HG
Dept. of Medicine (Nephrology Division), Georgetown University Medical Center, Washington, DC 20007.
Razavi
M H
MH
Slemmer
D
D
Zein
M
M
D000618:Aminohippuric Acids / Q000097:blood*; D003124:Colorimetry; D005189:False Positive Reactions; D006801:Humans; D000439:Pentanols; D013420:Sulfamethoxazole / Q000097:blood*; D013449:Sulfonamides / Q000097:blood; D010130:p-Aminohippuric Acid / Q000097:blood*
D000618:Aminohippuric Acids; D000439:Pentanols; D013449:Sulfonamides; D013420:Sulfamethoxazole; D010130:p-Aminohippuric Acid; C020377:isoamyl acetate