ABSTRAKPenggunaan tungsten oksida sebagai elektroda untuk mendeteksi keberadaan asam aspartat, glutamat dan arginin dalam larutan secara potensiometri dilakukan dalam sistem batch. Karakterisasi elektroda tungsten oksida yang digunakan meliputi rentang linier, limit deteksi, sensitivitas dan reprodusibilitas. Pengaruh jenis buffer dan konsentrasinya dalam analisis juga dipelajari untuk mengoptimasi hasil pengukuran. Dari hasil penelitian, diperoleh kondisi optimum untuk mendeteksi arginin adalah pada buffer fosfat pH 6,0 dengan konsentrasi 0,5 x 10 -3 M. Koefisien korelasi diperoleh sebesar 0,9864, limit deteksi 5,24 x 10 -6 M, sensitivitas 16,1 mV/dekade dengan reprodusibilitas 0 -7 %. Asam glutamat memiliki koefisien korelasi 0,9789, limit deteksi 3,80 x 10 -6 M, sensitivitas 9,2 mV/dekade dan reprodusibilitas 0 -6 %. Asam aspartat memiliki koefisien korelasi 0,9949, limit deteksi 7,76 x 10 -6 M, sensitivitas 13,4 mV/dekade dan reprodusibilitas 0 -5 %.Kata kunci: asam amino, batch, potensiometri, tungsten oksida ABSTRACTThe presence of aspartic acid, glutamic acid and arginine in solution can be detected by potentiometric method using tungsten oxide electrode in a batch system. Characterization of tungsten oxide electrode used include linear range, limit of detection, sensitivity and reproducibility. Buffer type and concentration effect also studied to optimize the measurement results. Optimum conditions for detecting arginine was at pH 6.0 with a phosphate buffer concentration of 0.5 x 10 -3 M. Correlation coefficient was obtained for 0.9864, the detection limit of 5.24 x 10 -6 M, sensitivity 16.1 mV/decade with reproducibility 0 -7 %. Glutamic acid has a correlation coefficient of 0.9789, the detection limit of 3.80 x 10 -6 M, the sensitivity of 9.2 mV/decade and reproducibility of 0 -6 %. Aspartic acid has a correlation coefficient of 0.9949, the detection limit of 7.76 x 10 -6 M, sensitivity of 13.4 mV/decade and reproducibility of 0 -5 %.

<p>The presence of aspartic acid, glutamic acid and arginine in solution can be detected by potentiometric method using tungsten oxide electrode in a batch system. Characterization of tungsten oxide electrode used include linear range, limit of detection, sensitivity and reproducibility. Buffer type and concentration effect also studied to optimize the measurement results. Optimum conditions for detecting arginine was at pH 6.0 with a phosphate buffer concentration of 0.5 x 10^-3 M. Correlation coefficient was obtained for 0.9864, the detection limit of 5.24 x 10^-6 M, sensitivity 16.1 mV/decade with reproducibility 0 –7 %. Glutamic acid has a correlation coefficient of 0.9789, the detection limit of 3.80 x 10^-6 M, the sensitivity of 9.2 mV/decade and reproducibility of 0 – 6 %. Aspartic acid has a correlation coefficient of 0.9949, the detection limit of 7.76 x 10^-6 M, sensitivity of 13.4 mV/decade and reproducibility of 0 – 5 %.</p>