Electronic Theses and Dissertation

Validasi penentuan urea dalam saliva menggunakan metode biosensor dan metode p-dimethylaminobenzaldehyde (dmab) telah berhasil dilakukan. senyawa antosianin dari bunga chatarantus roseus diekstraksi dengan metode maserasi menggunakan pelarut metanol dan diperoleh total rendemen sebesar 22,60 % dengan total konsentrasi sebesar 6,01 mg/l. ekstrak yang diperoleh dilakukan pengujian antosianin secara kualitatif dengan uji positif ditandai dengan terbentuknya warna kemerahan dan kuantitatif terbentuknya warna kuning memudar. panjang gelombang maksimum (λmaks) antosianin adalah 664 nm dengan absorbansi 0,674. pengambilan sampel saliva terdiri dari tiga kategori yaitu anak-anak, remaja, dewasa. selama proses pengumpulan saliva, diharuskan untuk tidak makan dan minum (kecuali air putih) minimal 1 jam sebelum pengambilan saliva dilakukan. kemudian ketika sudah terkumpul sampel saliva dilakukan penyimpanan didalam freezer sampai kembali dibutuhkan untuk analisa. hasil uji linearitas diperoleh dengan kurva kalibrasi dengan koefisien determinasi biosensor (r2= 0,978) dengan sensitivitas 0,033 dan dmab (r2= 0,975) dengan sensitivitas 0,685. nilai pengujian lod biosensor dan dmab memperoleh nilai serendah 7,203x10-11 m dan 6,984x10-6 m sedangkan untuk loq biosensor dan dmab 2,182x10-10 m dan 2,116x10-5 m. perhitungan uji t dapat menunjukkan bahwa thitung memperoleh 1,314 dan ttabel 4,302 yang menandakan thitung < ttabel. pengujian uji t dapat disimpulkan bahwa metode biosensor sama baiknya dengan dmab atau tidak ada perbedaan yang signifikan. indikasi terhadap hasil penentuan urea menunjukkan bahwa sampel dewasa memiliki konsentrasi urea yang paling tinggi diantara sampel lain dan dapat memungkinkan untuk terjadinya beberapa penyakit seperti karies gigi, gagal ginjal, bahkan kerusakan pada hati.

The validation of urea determination in saliva using the Biosensor method and the p-dimethylaminobenzaldehyde (DMAB) method has been successfully conducted. Anthocyanin compounds from Chatarantus roseus flowers were extracted using the maceration method with methanol as the solvent, yielding a total of 22.60% with a total concentration of 6.01 mg/L. The obtained extract was subjected to qualitative anthocyanin testing, showing a positive result marked by the formation of a reddish color and quantitative testing with the formation of a faded yellow color. The maximum wavelength (λmax) of anthocyanin is 664 nm with an absorbance of 0.674. Saliva sampling consisted of three categories: children, teenagers, and adults. During the saliva collection process, it was required not to eat or drink (except for water) for at least 1 hour before the saliva collection. The saliva samples were stored in a freezer until needed for analysis. The linearity test results were obtained with a calibration curve with a Biosensor determination coefficient (R² = 0.978) with a sensitivity of 0.033 and DMAB (R² = 0.975) with a sensitivity of 0.685. The LOD testing values for the biosensor and DMAB were as low as 7.203x10⁻¹¹ M and 6.984x10⁻⁶ M respectively, while the LOQ values for the biosensor and DMAB were 2.182x10⁻¹⁰ M and 2.116x10⁻⁵ M, respectively. The t-test calculation showed that tcalculated was 1.314 and ttable was 4.302, indicating tcalculated < ttable. The t-test results concluded that the biosensor method is as good as the DMAB method, showing no significant difference. The indication from the urea determination results shows that the adult samples have the highest urea concentration among the other samples and may be associated with the potential for several diseases such as dental caries, kidney failure, and even liver damage.