CPC G01N 33/92 (2013.01) [G01N 21/255 (2013.01); G01N 21/31 (2013.01); G01N 33/94 (2013.01); G01N 2021/3129 (2013.01); G01N 2201/1293 (2013.01)] | 18 Claims |
1. A method for determining a state of fitness of a spectrophotometer comprising:
testing the spectrophotometer by
measuring absorbance values for a predetermined concentration of a standard at a predetermined wavelength and multiple pathlengths using variable path length spectroscopy;
calculating a slope value of the standard from a linear regression of the absorbance values at the multiple pathlengths;
comparing the calculated slope value to a certified slope value or to the corresponding slope value on a standard curve to determine the state of fitness of the spectrophotometer,
wherein the standard is a methylxanthine or a compound selected from the group consisting of NaCl, KHP, KCl and KCr2O4.
|