Penentuan Ketidakpastian Pengukuran Kadar Kafein pada Biji Kakao (Theobroma Cacao L.) Menggunakan Spektrofotometri UV-Vis

Devita Wijiyanti (Jurusan Kimia, FMIPA Universitas Islam Indonesia Yogyakarta)
Thorikul Huda (Jurusan Kimia, FMIPA Universitas Islam Indonesia Yogyakarta)

JC-T (Journal Cis-Trans) : Jurnal Kimia dan Terapannya
Vol. 1 No. 2 (2017)

A study on the determination of uncertainty in measurement of caffeine content in cocoa beans by UV -Vis spectrophotometer method. The aim of this study was to determine the uncertainty of measurement of caffeine content in cocoa beans. Caffeine in cocoa bean extract was analyzed using UV-Vis spectrophotometer at 273 nm wavelength, obtained by linear regression equation y=0,0497x+0,0028 with determinant coefficient R2 0,9996. The results showed that caffeine content of 26.40 mg/g. LOD and LOQ values were 0.52 mg/L and 1.73 mg/L. The contributing factors of uncertainty are concentration (c), mass (m), dilution factor and precision with an estimated uncertainty of measurement of 3.11 mg/g. Test results can be reported with a value of 26.40 ± 3.11 mg/g.