SEQUENTIAL INJECTION-FLOW REVERSAL MIXING (SI-FRM) UNTUK PENENTUAN KREATININ DALAM URIN - Sabarudin, A; Wulandari, ERN; Sulistyarti, H (Indonesian Journal of Mathematics and Natural Sciences, 2012)
Jumlah kreatinin yang diekskresikan melalui urin menunjukkan keadaan ginjal seseorang. Dalam penelitian ini, dikembangkan metode untuk penentuan kreatinin secara otomatis yaitu sequential injection-flow reversal mixing (SI-FRM). Pendeteksian kreatinin didasarkan pada pembentukan senyawa berwarna (merah-orange) yang dihasilkan dari reaksi antara kreatinin dan asam pikrat dalam suasana basa dan diukur pada panjang gelombang 530 nm. Reaksi pembentukan senyawa kreatinin-pikrat dilakukan melalui pembentukan segmen antara sampel dan reagen di-holding coil dan selanjutnya dilakukan proses flow reversal di-mixing coil. Parameter-parameter yang mempengaruhi metode ini diuji secara detail. Hasil penelitian menunjukkan bahwa kondisi optimum pengukuran kreatinin yaitu menggunakan konsentrasi asam pikrat 0,035 M dan NaOH 3,5%, laju alir flow reversal 5 µL/detik, laju alir produk reaksi 20 µL/detik, jumlah flow reversal empat kali dan menggunakan tiga segmen (pikrat-kreatinin-pikrat) dengan masing-masing volume segmen 100 µL. Metode SI-FRM ini telah diaplikasikan langsung untuk penentuan kadar kreatinin dalam urin dengan limit deteksi 1,7 µg/g. The amount of creatinine excreted in urine indicates kidney condition. In this experiment, the automatic determination method of determining creatinine was developed by using sequential injection-flow reversal mixing (SI-FRM). The detection of creatinine is based on the formation of a colored product (red-orange) yielded from the reaction of creatinine with picrate at alkaline medium. The absorbance is measured at wavelength of 530 nm. The formation of creatinine-picrate complex is performed through the segment formation between sample and reagent in the holding coil and then flow reversal process in the mixing coil of SI-FRM. Several parameters affecting to this method are investigated in detail. The results show that the optimum concentrations of picric acid and NaOH are 0.035 M and 3.5%, respectively. Other optimized conditions, such as the flow reversal rate of there 5 µL/s, flow rate of product of 20 µL/s, amount of flow reversal process of four times, and segment amount of three (picrate-creatinine -picrate) with each volume of 100 µL, were obtained. This method is successfully applied to the determination of creatinine in urine with the detection limit of 1.7 µg/g.