Determination of dissolved solids using synthetic urine via laser refractometry

A laser refractometer was used to measure the refractive index of synthetic urine samples ranging in specific gravity of 1.028g/mL to 1.010g/mL. When analyzing a urine sample, it’s very important that the sample is not destroyed. Laser refractometry is a nondestructive analytical method that can determine the concentration of a sample based on its refractive index. The instrument used in this study utilizes an inexpensive laser that passes through a cuvet filled with a sample, and its deflection is measured on a linear photoarray. A hydrometer was used to measure and confirm the specific gravity. After three trials, it was found that urine samples exhibiting a higher specific gravity had the lowest peak value (40) while the samples with the lowest specific gravity had the highest peak value (114). The range of values found during this experiment can be applied to future tests as a standard to be compared against.