Improvement in quantification of urine components: Alternate technique
  Urea and creatinine are two important diagnostic components of urine. The study of creatinine in liquid phase is difficult due to its feeble concentration in urine. To bring down the detection limit, Raman spectroscopy of dried urine samples was employed. Raman studies in association with partial least square algorithm of artificial urine samples gave improved results in dried phase as compared to liquid phase. These findings were further validated on real urine samples. 
S. Kumar, S. K. Majumdar
physics.med-ph