A visible light spectrophotometric determination of penicillin makes use of color-forming reaction of the penicillin. If...

4.1 Ratings (508 Votes)

Ans. Beer-Lambertâ€™s Law, A =e C LÂ Â Â Â Â Â Â Â Â Â Â Â Â Â Â - equation 1,Â Â Â Â Â Â Â Â Â Â Â Â Â Â where,

Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â A = Absorbance

Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â e = molar absorptivity at specified wavelength

Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â L = path length (in cm)

Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â C = Molar concentration of the solute

Given,

Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â e = 1560 M^-1cm^-1

Â Â Â Â Â Â Â Â Â Â Â L = 1.0 cm

Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â A = 0.005Â Â Â Â Â Â Â Â Â Â Â Â Â - smallest absorbance, limiting detection

Putting the values in equation 1

Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 0.005 = 1560 M^-1cm^-1 x C x 1.0 cm

Â Â Â Â Â Â Â Â Â Â Â Or, C = (0.005) / (1560 M^-1) = 3.20 x 10^-6 M

That the as small as 3.20 x 10^-6 M concentation of penicillin can be detected using the specified VIS-spectrophotometer.

Thus, detection limit = 3.20 x 10^-6 M = 3.20 x 10^-6 moles /L Â Â

Join us to gain access to millions of questions and expert answers. Enjoy exclusive benefits tailored just for you!

Unlimited Question Access with detailed Answers
Zin AI - 3 Million Words
10 Dall-E 3 Images
20 Plot Generations
Conversation with Dialogue Memory
No Ads, Ever!
Access to Our Best AI Platform: Flex AI - Your personal assistant for all your inquiries!

Become a Member

Other questions asked by students