(9) Internal Revenue Code means the Internal Revenue Code of 1986 in effect for the federal tax year beginning on January 1, 2007, not including any changes made by federal law after that date, and any regulations adopted under that code applicable to that period.
Absorbance spectroscopy, commonly referred to as spectrophotometry, is the analytical technique based on measuring the amount of light absorbed by a sample at a given wavelength.
The instrument used to measure the amount of light of a specific wavelength absorbed or transmitted by a substance is called a spectrophotometer. In a spectrophotometer, a sample of the substance is placed across the path of a light beam of a chosen specific wavelength. The spectrophotometer determines the intensity of the light entering the sample and the intensity of the light leaving the sample, then calculates the amount of light transmitted and absorbed by the substance.