Quartz Cuvette Cleaning Procedure
Clean cuvettes are the foundation of any photometric measurements. Even plastic cuvettes are disposable and no need to worry about cleaning, the rest of the quartz or glass cuvettes are reusable and require cleaning to avoid cross-contamination.
Quartz Cuvettes Require Cleaning
Why Clean the Cuvettes?
- Residues from the previous analysis will result in imprecision, low sensitivity, inaccuracy, and contamination.
- More importantly, it will waste your time repeating the experiments!
- It helps to inspect the cuvette’s condition. It is important to replace the cuvettes with new ones if they are cracked or scratched, since, to save your valuable time and samples.
Before we start:
Personal Protection
It’s required to wear goggles, safety glasses, nitrile gloves, and a lab coat when operating cleaning. Handling of concentrated hydrochloric acid (HCl) must be in a fume hood.
Hazards
Breaking an optical cuvette may lead to wounds, so treat them with care.
A laboratory fire may be caused by the use of flammable solvents including methanol and acetone. Remember to use these solvents in the fume hood so you don’t inhale them.
Concentrated hydrochloric acid can cause burns and irritates airways as well. Wear gloves and only open the solvents in a working fume hood.
Cuvette Clean Methods:
NRC glued cuvettes are available from iCuvets.Com for researchers with a tight budget. These cuvettes can only be used with aqueous samples such as DNA, Protein, and Biologics Solutions. CRF or HTR cuvettes can hold most chemicals including organic based solutions.
Further reading: Explanation of HTR, CRF, NRC and Chemical Resistance
It is important to know the cuvette nature and the residual material to be removed from the cuvettes. Here is the table for some suggestions for cuvette cleaning:
| Solution | Sample Type | Cuvette Cleaning Procedure |
| Aqueous | Protein, DNA, RNA, Biologics | Empty cell, Warm water with detergent, Rinse with Dilute acid, Filled water rinse, Repeat 2-3 times |
| Aqueous | Salt solution | Rinse with warm water Acid, Copious water rinse, Repeat 2-3 times |
| Aqueous | Basic solutions | Empty cell, Warm water with detergent, Rinse with Dilute acid, Filled water rinse, Repeat 2-3 times |
| Organic | Oil based | Operate in Fume Hood, Rinse with solvent, Warm water with detergent, Dilute acid, Filled water rinse, Repeat 2-3 times |
| Organic | Alcohol solutions | In Fume Hood, Solvent rinse, Copious water rinse, Repeat 2-3 times |
| Organic | Acidic solutions | In Fume Hood, Solvent rinse, Copious water rinse, Repeat 2-3 times |
| Organic | Basic solutions | Operate in Fume Hood, Rinse with solvent, Dilute acid rinse, Copious water rinse, Repeat |
| Fluorescence | Clean cuvettes in Nitric Acid (5 M), Copious water rinse immediately before use |
Some Suggestions about Using Cuvettes:
- First of all, keeping the cuvette clean while in use. This is a very important element of keeping the cuvette a long, useful life.
- Never let your cuvettes dry out. Try to keep them in water or a solvent bath between usage, so that they will not dry out and stick.
- Only lens cleaning tissue or fine wiper cloth to clean the optical sides. Most tissue paper contains wood fibers
- Please be aware to only use lens cleaning tissue or lens cloth to clear the polished surfaces. Most paper tissue contains fiber wood which will scratch the clear polished sides.
Upon drying, ensure all cuvettes are well cleaned and stored in a suitable place.
Note: Don’t rinse NRC glued cuvettes with acids, alcohol, or solvents >20 seconds.
| Dilute Acid | Dilute Hydrochloric acid (HCl, 2M) or Nitric Acid (HNO3 , 2M) |
| Acid | Hydrochloric Acid (HCl, 5M) acid or Nitric Acid (HNO3 , 5M)* |
| Solvent rinse | Rinse with the chemical that solvated the sample in the first place! |
| Copious water rinse | Using deionized, distilled or RO water and rinse at least 10 times the volume |
| Detergent | If available, use a neutral pH detergent but diluted acid and distilled water to remove detergent residues |
Important Note:
*5M Nitric acid (HNO3 ): Do not use this chemical on Anti-reflection or mirror coated cuvettes
Ultrasonic Cleaning:
The use of ultrasonic cleaning baths with cuvettes is not recommended.
Every cleaner generates a different frequency and the cuvette might break if the bath operates at the resonant frequency of cuvettes. Our warranty does not cover cuvettes for cleaning in an ultrasonic cleaner.