Water testing regulations—though stringent—have historically lacked an element of precision. In the past, it was sufficient to evaluate the color of water and wastewater according to a grading known as water-white. This was a general evaluation for solvents that have the appearance of clear water. It was an inaccurate technique that was made worse as different expressions of the terminology arose over time, meaning there was no universal standard for what water-white actually entailed.
Custom CRMs (Certified Reference Materials) have helped innovate water and wastewater testing by introducing unprecedented levels of precision to the workflow. But before we explore the role of custom CRMs in water testing, it is worthwhile looking at the innovative method that replaced the water-white colorimetric scale.
What is the Platinum-Cobalt Method?
A new colorimetric scale was introduced to resolve the issues associated with water-white. Drawing from an index originally developed for the evaluation of pollutant levels in wastewater, the new platinum-cobalt (Pt-Co) scale provided the basis for a precise method of testing impurities in water using spectroscopy. Rather than a rudimentary visual comparison, the Pt-Co method deploys a spectrometer with an ultraviolet-visible (Uv/Vis) light source to assess the intensity of yellow hue in water sources. The Pt-Co Colour scale ranges from 0 to 500 ppm Colour Units (CU). Typically, analysts will prepare a 500ppm CU standard from Potassium hexachloroplatinate and Cobalt (II) Chloride. Working solutions would then be created by diluting the 500 ppm CU standard. This method is ideal for analysts looking to precisely determine impurities in near-colorless samples.
Why Custom CRMs Matter in Water Testing
Accuracy is the cornerstone of scientific testing, and though the Pt-Co scale introduces a new level of precision to water testing, this is dependent on instrument verification. UV/Vis spectrometers must be calibrated to validate output signals using standards of know concentration. Reference materials can be custom-mixed in-house, but this defies the goal of increasing the accuracy and traceability of critical water testing objectives.
Custom CRMs from a trusted supplier ensure that your instrument verification protocols always begin with the right materials and follow the prescribed method. They assure that your results are not only credible but are reliable and repeatable.
Looking for Custom CRMs for Water Testing?
Inorganic Ventures specializes in the generation of custom CRMs and standards for various instrument validation protocols. Our brand-new Pt-Co standard (IV-57433) is a future-proof material backed up by extensive chemical expertise and unflinching support. We guarantee 100% consistency and reliability, and with our proprietary TCT packaging, we can also offer a 4-year expiration date to alleviate any concerns about shipping and storage. Read about our custom CRM for Pt-Co testing, and the benefits of our TCT system.