Electronic Theses and Dissertation

Penelitian ini mengembangkan instrumen ukur alternatif mini studio cuboid berbasis smartphone untuk mengatasi keterbatasan aksesibilitas dan mobilitas alat konvensional. Sistem pencahayaan dikontrol menggunakan LED putih polikromatik dan diffuser. Evaluasi kinerja difokuskan pada analisis komparatif antara alat usulan dengan spektrofotometer UV-Vis dalam mendeteksi kadar Rhodamin B pada sirup. Hasil validasi membuktikan performa analitik smartphone sebanding dengan UV-Vis. Linearitas smartphone mencapai (R²=0,998), setara dengan UV-Vis (R²=0,999). Akurasi (% recovery) smartphone berada pada 93,7-110%, sedangkan UV-Vis 96,7-110 %. Kedua metode berpresisi sangat baik (%RSD ≤ 2%), yakni 0,789-1,28% (smartphone) dan 0,0661-1,09% (UV-Vis). Batas deteksi (LoD) dan kuantitasi (LoQ) smartphone sebesar 0,452 mg/L dan 1,508 mg/L, sebanding dengan UV-Vis (LoD 0,377 mg/L; LoQ 1,255 mg/L). Pengujian pada sampel mengonfirmasi selisih konsentrasi yang tidak berbeda signifikan antar kedua alat, sehingga mini studio smartphone valid dan layak menjadi alternatif yang praktis, portabel, dan ekonomis untuk menunjang kebutuhan penelitian dan pendidikan.

Kata Kunci: Mini studio cuboid, Smartphone, Rhodamin B, Spektrofotometer UV-Vis

This study developed an alternative smartphone-based cuboid mini studio to address the limitations of conventional measurement devices in terms of accessibility and mobility. The lighting system is controlled using polychromatic white LEDs and a diffuser. The performance evaluation focused on a comparative analysis between the proposed device and a UV-Vis spectrophotometer in detecting Rhodamine B levels in syrup. Validation results demonstrate that the analytical performance of the smartphone method is comparable to that of the UV-Vis spectrophotometer. The smartphone's linearity achieved an R² of 0.998, equivalent to that of the UV-Vis (R² = 0.999). The smartphone's accuracy (% recovery) ranged from 99.43% to 110%, while the UV-Vis ranged from 97.57% to 110%. Both methods exhibited excellent precision (%RSD ≤ 2%), specifically 0,789-1,28% (smartphone) and 0,0661-1,09% (UV-Vis). The limit of detection (LoD) and limit of quantification (LoQ) for the smartphone were 0.452 mg/L and 1.508 mg/L, comparable to those of the UV-Vis (LoD 0.377 mg/L; LoQ 1.255 mg/L). Testing on samples confirmed no significant difference in the concentrations detected by the two instruments. Therefore, the smartphone-based mini studio is valid and suitable as a practical, portable, and economical alternative to support research and educational needs. Keywords: Cuboid mini studio, Smartphone, Rhodamine B, UV-Vis spectrophotometer