Question

what are steps you should take before finding the absorbance of any of your samples? (select all that apply)
rinse with solution being tested
place cuvette in spectrophotometer, orientation matters
wipe with kim wipe
calibrate with solvent of solution being tested
place cuvette in spectrophotometer, orientation doesnt matter
wipe with paper towel
rinse with soap
calibrate with solution being tested

Explanation:

Before measuring absorbance, cuvettes should be wiped with a lint - free wipe like a Kim - wipe to remove fingerprints and other contaminants that could affect readings. The cuvette should be placed in the spectrophotometer with the correct orientation as some cuvettes have specific optical properties related to their orientation. Also, the spectrophotometer must be calibrated with the solvent of the solution being tested to set the baseline absorbance to zero. Rinsing with the solution being tested can introduce errors if not done properly, rinsing with soap is unnecessary and can leave residues, wiping with a paper towel may leave lint, and calibrating with the solution being tested is incorrect as the baseline should be set with the solvent.

Answer:

• wipe with Kim wipe
• place cuvette in spectrophotometer, orientation matters
• calibrate with solvent of solution being tested