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过程工程学报 2009
Simultaneous Determination of Amino Acids and Inorganic Cations by Ion Chromatography with Direct Conductivity Detection
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Abstract:
A simple, rapid and accurate method for simultaneous determination of six amino acids (glutamic acid, alanine, methionine, leucine, phenylalanine and lysine) and five inorganic cations (Na~+, NH_4~+, K~+, Ca~(2+) and Mg~(2+)) was developed. The quantitative determination of these ions was accomplished by ion chromatography with direct conductivity detection based on their ionization in acidic medium without chemical suppression and derivatization. In a single chromatographic run, the five amino acids (glutamic acid, alanine, methionine, leucine and phenylalanine) and three inorganic cations (Na~+, NH_4~+ and K~+) were separated and determined within 12 min. The relative standard deviation (RSD, n=5) was less than 4.690%. The detection limits calculated were in the range from 0.27 to 10.34 mg/L. All the correlation coefficients (R~2) of these ions were not less than 0.9984. The recovery rates of some amino acids in isoelectric supernant of monosodium glutamate were in the range from 88.7% to 107.2%.