Patent ID: 7660678

Claim:
A method of confirming the concentration or purity of a sample of a liquid having a desired concentration or purity, comprising the steps of: introducing a sample of a liquid having a desired concentration or purity into a liquid sample channel of a hand-held analytical instrument, said hand-held analytical apparatus comprising apparatus for performing a spectral analysis of the sample in at least two liquid sample channels each having a different path length of about 0.025 mm to at least about 1.0 cm; performing a spectral analysis of sample liquid in said sample channel with said apparatus for performing a spectral analysis; obtaining data regarding the spectral analysis of the sample; comparing the data regarding the spectral analysis of the sample having a desired concentration or purity to spectral analyses of samples having a predetermined concentration or purity stored in a retrievable form; mathematically calculating a concentration or purity of the sample having desired concentration or purity from the comparison; and confirming whether or not the determined concentration and purity of the sample having a desired concentration and purity is a desired concentration and purity.