Wine Analysis Home
Safety Precautions
Chemicals and chemical solutions
Acids and Bases
Storage
Glassware
Pipette filler
Working systematically
Chemicals and chemical solutions
- All chemicals should be considered harmfull and safety information ascertained before use.
- It is important to label all containers containing chemicals indicating their contents and safety warnings and date of purchase as a minimum.
Containers containing chemical solutions should be labeled with their contents, concentration and safety warnings as a minimum. In addition, for convenience, the date prepared and/or date last standardized and name of the person involved should also be included.
Acids and Bases
- When mixing acids with water always add the Acid to Water (Mnemonic A before W).
- In the preparation of some acid solutions, heat can be generated during addition and therefore should be carried out slowly and the container exterior may require cooling in a bath containing an ice and water mixture.
Storage
- Always store chemical solutions in appropriate containers with secure and appropriate lids.
Sulphur dioxide ( SO2) and caustic solutions such as sodium hydroxide ( NaOH ) will cause glass stoppers in glass bottles to cease up. Plastic screw lids or less desirable plastic stoppers in glass bottles are recommended in these cases.
- A storage cupboard dedicated to chemicals and chemical solutions is highly recommended and positioned in a appropriate position.
DO NOT STORE CHEMICAL SOLUTIONS, THAT NEED TO BE KEPT REFRIGERATED, IN THE FAMILY FRIDGE.
Glassware
When manipulating glass apparatus, always hold it as close to the site of operation as possible, to reduce leverage. This especially applies when fitting a pipette filler to a pipette, hosing to a hose connection or tightening ground glass joints on glass apparatus.
This reduces the risk of glass breakage and consequent injuries.
Using a thick rag or strong cloves can also reduce injury if accidental breakage occurs.
When clamping glassware it pays to release the various holding components to relief any tension indicated by movement on loosening. Release tension in each holding point in turn until no movement is observed. Any tension in the system can cause breakage at some later time due to glass fatigue.
Pipette filler
Winemakers tend not to use pipette fillers as a lot of the chemicals they use are not fatal if swallowed, but accidents are events that are not anticipated.
This anecdote may convince you to use a pipette filler.
A fellow winemaker came to visit me while I was preparing a 0.3 % hydrogen peroxide (H2O2) solution . I was called away and he volunteered to take on the task. Using his mouth to suck up a 30% H2O2 solution into the pipette, he was not aware of the level of the solution in the black non-transparent bottle. Assuming it was full, the pipette was filling nicely until the pipette was lifted slightly and found the air space above the solution while sucking. The lower resistance of air shot the concentrated, 30 % H2O2 solution into his mouth.
Luckily copious rinses with water saved his mouth from suffering severe burns and luckily none got into his lungs. It could have been disastrous. Yet he had been getting away without a pipette filler in his own environment. It is the unexpected that will get you and it only takes one occasion for permanent damage.
Use a pipette filler. Even if you think it's the wine sample you are sucking up. Some unlabeled beakers (hence the need for labeling), can look deceptively like a wine sample.
Working systematically
- When working with a number of solutions during any chemical analysis it pays to work systematically.
This includes immediately closing bottles after use to prevent accidental spillage.
Leaving lids off can result in a mix up between similar lids with possible contamination of solutions.
- Dedicate a pipette per solution even if the same volumes are involved and pair them with each solution by placing them along side on the right of each bottle.
This prevents confusion, contamination and allows continual re-use when performing a number of analysis.
- Label now!