[Direct determination of ammonia in plasma with indophenol method].
A new method for direct determination of ammonia in plasmas with indophenol reagent is described. It is shown that using sodium citrate as anticoagulant in phosphate buffer within pH 10.5-11.2, indophenol reagent reacts sensitively with ammonia in the plasmas to form a stable blue compound with a maximum absorption at 630 nm with low interference. The apparent molor absorptivity is 2.48 x 10(4) L x mol(-1) cm(-1) , and the linear range 0-1500 micromol x L(-1) (r = 0.9999) with a detection limit of 1.7 micromol x L(-1). The relative standard deviation is 1.13% (n=11) and the recoveries are in the range of 93.6%-101.6% with an average recovery of 97. 0%. The proposed method has been applied to detect ammonia in the plasmas from 43 healthy persons and 97 patients who suffered from liver diseases with satisfactory results.
Deng
Jian
J
College of Chemistry and Chemical Engineering, Nanhua University, Hengyang 421001, China.
Xu
Jin-sheng
JS
Fan
Hua
H
Yuan
Ya-li
YL
Liu
Chuan-xiang
CX
D000641:Ammonia / Q000097:blood* / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007215:Indophenol / Q000737:chemistry*; D008107:Liver Diseases / Q000097:blood / Q000175:diagnosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013053:Spectrophotometry; D013997:Time Factors
D007215:Indophenol; D000641:Ammonia