A new water standard for running low-level calibration checks under 35ppm on your Karl Fisher Titrator has recently been introduced.  This Fluka brand product is being offered by Sigma-Aldrich and has the product name “Hydranal-Water Standard, oil”.

Unlike other Hydranal solvent-based water standards you may be familiar with like, 1.0 (1,000ppm +-3%) and 0.1(100ppm +-10%), this new standard uses actual oil as the carrier for the water in the standard.

Because this standard is oil-based Sigma-Aldrich recommends the operator use a reagent (or solvent system) that will dissolve an oil.  So either Coulomat Oil or Coulomat A or even AG-H should be used.  This is not a standard that is recommended for someone using Coulomat AG or AD with their coulometric Karl Fisher titrator.

According to the Sigma-Aldrich technical center this standard is obtained by LOT and certified to have a certain level of moisture.  Sigma-Aldrich will select and test a LOT and certify the results.  For example, the current LOT 72980 was tested and measured against NIST SRM 2890 where the LOT was identified to have the following results; Water Content (coulometric) of 6.0ppm, Water Content (volumetric) of 5.6ppm and Water Content (oven coul.) of 6.5 ppm.  So depending on different LOTs and certification the water content will vary by LOT.  Some LOTs in the future may have 8.0ppm or 10.0ppm, etc. – But never to have a LOT to exceed 35.0ppm.

Sigma-Aldrich recommends using 2mL of standard per injection and also noted that unlike the other solvent-based standards an advantage of this standard is it’s stability and ease of use.  Because this standard is so new it’s not clear how customers will fare with it but it is the hope that it will address the needs of those operators wanting to run very low-level calibration checks on their Karl Fisher Titrators.

Hope this helps.

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