Ion Chromatography: Environmental Analyses & Post-Column Derivatization
I am happy to report that this is my first blog post for Chromatography Solutions, and that I will now be blogging about a mix of chromatography topics—from stories about our customers’ successes and human interest, to reviewing journal articles, webinars, and trends in relevant industries.
I found this story interesting because it’s about a customer who, like us, is also a supplier of laboratory equipment and hardware—Pickering Laboratories. I am happy to report that Pickering Labs is now exclusively using our ion chromatography (IC) systems (links to Thermo Scientific IC systems) with their post-column derivatization system (links to Pickering Laboratories derivatization systems) to develop their environmental applications. They’ve demonstrated application of the combined systems for bromate, nitrate, and nitrate, and just recently released and application note for Hexavalent Chromium (Cr[VI]), Highly Sensitive Analysis of Chromium (VI) in Drinking Water by Ion Chromatography with Post-Column Derivatization and UV-Vis Detection, (links to a downloadable PDF of the application note). When I spoke with Pickering Laboratories’ Wendy Rasmussen, she said the reason they chose our IC systems was because, “We have a great relationship with Dionex [now Thermo Scientific] and their ion chromatography systems have an excellent reputation.”
EPA Method 218.7 for Cr(VI) (links to EPA hexavalent chromium web page) requires post-column derivatization with diphenylcarbazide to enable UV-Vis detection at 530 nm. Although post-column derivatization is integral to our IC systems as demonstrated in our Application Update 144, Determination of Hexavalent Chromium in Drinking Water Using Ion Chromatography (links to downloadable PDF of the app note), the Pickering Labs system is an option for environmental labs performing multiple applications, such as such as glyphosate herbicide, amino acid analysis, or carbamate pesticides, where temperature control and precise flows with software control is needed in the derivatization methodology. Their application note demonstrates that the Pickering Laboratories’ post-column system seamlessly connects with our IC systems without a loss in sensitivity saying, it “… is uniquely suitable for delivering aggressive derivatization reagents with unmatched flow precision and low noise level in order to consistently provide highly sensitive detection of Hexavalent Chromium.”
If you want to know more about Cr(VI) analysis, we have several resources. Our Hexavalent Chromium website discusses Cr(VI) analysis in drinking water with free access to important applications notes following EPA methods. AU144, Determination of Hexavalent Chromium in Drinking Water Using Ion Chromatography, (links to a downloadable PDF of the application note) is the U.S. EPA Method 218.6 with a method detection limit (MDL) for chromate at 0.02 μg/L and can support a reporting limit of 0.06 µg/L. Application Note 179, Sensitive Determination of Hexavalent Chromium in Drinking Water, (links to downloadable PDF of application note) demonstrates higher sensitivity for routine analysis at the proposed California PHG level of 0.02 μg/L. The website also provides methods for groundwater, industrial wastewater, and solid waste extracts.
This is not the first time we’ve blogged about Pickering Laboratories, but all of our previous articles were about food applications. We shared several of their posters in HPLC Analysis: Aflatoxins in Herbs, Spices, Peanuts, (links to blog article) and we also did a joint webinar, Analysis of Mycotoxins in Food Matrices, (links to on-demand webinar), which addresses the challenge of testing of mycotoxins in food and meets mycotoxin guidelines set by the U.S. FDA using our UHPLC methods to effectively detect aflatoxins as well as other key classes of mycotoxins.
Let us know if this application was helpful to you in your work in the Comments box below; we look forward to hearing from you.