Miratul Khasanah

ANALYSIS OF URIC ACID USING CARBON PASTE ELECTRODES MODIFIED BY MOLECULARLY IMPRINTED POLYMER AS POTENTIOMETRY SENSOR

The development of carbon paste electrodes modified with the molecularly imprinted polymer (MIP) for the potentiometric analysis of uric acid was carried out in this study. MIP was made from methyl methacrylate as a monomer, ethylene glycol dimethacrylate as crosslinker, and uric acid as a template. The carbon paste electrodes/MIP is produced from carbon, MIP, and paraffin with ratio 40 : 25 : 35 (%, w/w). The measurement of uric acid with carbon paste electrodes/MIP produced Nernst factor of 30.19 mV/decade with a measurement range of 10-10 M. The minimum detection limit of this method was 3.03.10 M, the precision and accuracy towards uric acid with a concentration of 10-10 M was ranging between 1.36-2.03% and 63.9-166%. The selectivity coefficient value was less than one which indicated that the electrode was selective against uric acid and was not interfered by urea. This electrode has a response time less than two minutes and lifetime is eight weeks with the usage is 104 times.

Carbon paste electrode modified molecularly imprinted polymer as a sensor for creatinine analysis by stripping voltammetry

Modification of carbon paste electrode with molecularly imprinted polymer (CP-MIP) as a voltammetric sensor for creatinine has been developed. MIP was synthesized by reacting melamine, chloranil and creatinine with a mole ratio of 1:1:0.1. Creatinine was extracted from polymer chain by using hot water to form a specific imprinted for creatinine molecule. Carbon paste-MIP electrode was prepared by mixing activated carbon, solid paraffin, and MIP in a 45:40:15(w/w %) ratio. The optimum conditions of creatinine analysis by differential pulse stripping voltammetry (DPSV) using the developed electrode were the accumulation potential -1000 mV during 90 s at pH 5. The precision of the method for 0.1-0.5 μlg/L creatinine was 88.7–96.3%, while the detection limit of this method was 0.0315 μlg/L. The accuracy compared by spectrophotometric method was 95.3–103.6%Modification of carbon paste electrode with molecularly imprinted polymer (CP-MIP) as a voltammetric sensor for creatinine has been developed. MIP was synthesized by reacting melamine, chloranil and creatinine with a mole ratio of 1:1:0.1. Creatinine was extracted from polymer chain by using hot water to form a specific imprinted for creatinine molecule. Carbon paste-MIP electrode was prepared by mixing activated carbon, solid paraffin, and MIP in a 45:40:15(w/w %) ratio. The optimum conditions of creatinine analysis by differential pulse stripping voltammetry (DPSV) using the developed electrode were the accumulation potential -1000 mV during 90 s at pH 5. The precision of the method for 0.1-0.5 μlg/L creatinine was 88.7–96.3%, while the detection limit of this method was 0.0315 μlg/L. The accuracy compared by spectrophotometric method was 95.3–103.6%

Imprinted zeolite modified carbon paste electrode as a potentiometric sensor for uric acid

Imprinted zeolite modified carbon paste electrode (carbon paste-IZ) has been developed and applied to determine uric acid by potentiometry. The imprinted zeolite (IZ) was synthesized by the mole ratio of uric acid/Si of 0.0306. The modified electrode was manufactured by mass ratio of carbon, IZ and solid paraffin was 40:25:35. The modified electrode had shown the measurement range of 10−5 M to 10−2 M with Nernst factor of 28.6 mV/decade, the detection limit of 5.86 × 10−6 M and the accuracy of 95.3 – 105.0%. Response time of the electrode for uric acid 10−5 M - 10−2 M was 25 - 44 s. The developed electrode showed the high selectivity toward uric acid in the urea matrix. Life time of the carbon paste-IZ electrode was 10 weeks.