Dilution Precision in Concentration Measurements

Q. Do I determine detergent dilution by weight or by volume or both?

A. In a laboratory setting, the most common method is to either make a weight/weight dilution (10-20 g Alconox detergent in 990 g of water), or a weight/volume dilution (10-20 g Alconox in 990 mL of water) for 1-2% solutions.  In manufacturing situations, often directions are written volume/volume or volume/weight.  Be sure to review How to Make a 1% Solution and our video.

For simplicity of calculations, we will focus on 1% solutions….AlconoxⓇ Powdered Precision Cleaner is a robust cleaning agent and will work fine if diluted volume/weight or volume/volume (10 mL Alconox/990 g Water or 10 mL Alconox/990 mL water). The typical density of powdered Alconox varies from 0.85-1.1 g/mL depending on humidity and settling, so on a weight basis making a solution from volume will result in a 0.85-1.1% solution.  This range is acceptable to use from a standpoint of critical cleaning when a 1% solution is called for.

If writing a procedure, use whatever method of deriving a 1% solution that is most convenient for your application. It is acceptable to use 1 L or 1 Kg of water instead of 990 mL or 990 g if that is a simpler way of making the 1% solution. In smaller scale settings, it is also acceptable to indicate 2 teaspoons Alconox powder per liter of water for the purpose of creating a 1% dilution as far as cleaning performance is concerned. We note that mathematically this may not be an exact 1.0% solution.

The idea is to have some way of measuring that controls the amount of Alconox detergent used.  This avoids the problems of inadequate cleaning or inadequate rinsing that can result from grossly under-dosing or overdosing, respectively, the amount of Alconox detergent in the 1% dilution.  More precisely, if there is not enough detergent, you may not get to desired cleanliness levels.  If there is far too much, your rinsing regimen may not be robust enough.

While essentially all Alconox Inc. detergents are initially recommended in the 1-2% range, there are many applications in which higher concentrations (and occasionally lower) are needed.  Please also note that the above calculations also hold for our other detergents, including liquid concentrates.You can scale the above calculations as needed, or contact us any time to verify.

We are also happy to discuss what concentration (and detergent of course) might be needed as an initial test/verification cleaning trial for your particular application.

To request an Alconox Inc. detergent for free, please complete the questionnaire at Get Sample. For more information about any one of our Alconox Inc. detergents, consult the technical bulletin for each product. Or click here to access each of our detergent’s Safety Data Sheets.

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