will need to dilute sample. If the the sample. absorbance is still too high, Repeat with any dilute again other samples. and repeat until an When you are accurate finished, clean the measurement cuvettes by first is obtained. emptying them, Then, multiply then flushing with the several changes of absorbance purified water. reading by the Next, flush with dilution factor several changes of to obtain the 70-95% ethanol. absorbance Finally, dry upside of the original down on a paper concentration. towel before storing in a safe place. Never use any abrasive If you are the last to cleansers, use the soaps, or spectrophotometer, brushes on power off the cuvettes. This instrument. can scratch them or leave a PART B: contaminating residue. READINGS Disposable Follow the plastic procedure for single cuvettes can wavelength be used a few readings with times before two modifications: they become scratched or In Step 3, choose 2 stained and for need to be discarded. readings. Clean these carefully and In Step 4, enter two they will last or more for several wavelengths. uses. Quartz PART C: ABSORBANCE cuvettes look SPECTRUM like glass and are made to Choose 3 for have a long Spectrum in the life. Treat
will need to dilute the sample. Repeat with any other samples. When you are finished, clean the cuvettes by first emptying them, then flushing with several changes of purified water. Next, flush with several changes of 70-95% ethanol. Finally, dry upside down on a paper towel before storing in a safe place. If you are the last to use the spectrophotometer, power off the instrument. PART B: READINGS Follow the procedure for single wavelength readings with two modifications: In Step 3, choose 2 for readings. In Step 4, enter two or more wavelengths. PART C: ABSORBANCE SPECTRUM Choose 3 for Spectrum in the sample. If the absorbance is still too high, dilute again and repeat until an accurate measurement is obtained. Then, multiply the absorbance reading by the dilution factor to obtain the absorbance of the original concentration. Never use any abrasive cleansers, soaps, or brushes on cuvettes. This can scratch them or leave a contaminating residue. Disposable plastic cuvettes can be used a few times before they become scratched or stained and need to be discarded. Clean these carefully and they will last for several uses. Quartz cuvettes look like glass and are made to have a long life. Treat