Instant Notes: Analytical Chemistry

Calculate the concentrations of X and Y in the mixture.

Using the Beer–Lambert law at each wavelength:

A =eXcXl+eYcYl

At 255 nm: 0.274/0.01 =4.60cX+3.88cY

At 330 nm: 0.111/0.01 =0.46cX+30.0cY

Solving these simultaneous equations gives

cX=5.71 mol m-^3 =5.71¥ 10 -^3 M

cY=0.288 mol m-^3 =2.88¥ 10 -^4 M

Table 3gives some examples of the use of UV-visible spectrometry and of

fluorimetry for quantitative analysis.

232 Section E – Spectrometric techniques