Quantification of urinary glucose and protein with test-strips through reflectometric analysis

Reflectometric measurement of urine test-strips, using the Urotron RL9, was employed to quantify urinary glucose and protein. Although the test-strips (Combur-9-Test) are designed for qualitative use, the reflectance intensities determined by the Urotron RL9 are applicable to quantitative analysis. Reflectance quantitation and conventional colorimetric methods were closely correlated for glucose (r = 0.953) and protein (r = 0.906). Intra-assay coefficients of variation of reflectance value were less than 5%. The negative influence of ascorbic acid on glucose determination was defined quantitatively. A significant positive interference from hemoglobin on protein determination was also demonstrated, but effectively eliminated after compensating for urine color.