#WatersforWater - LC/MS Drinking Waters analysis solution

Haloacidic Acids and Acrylamide

Haloacetic acids (HAAs) are disinfection by-products (DBPs) formed during the disinfection process of drinking water, when chlorine reacts with naturally occurring organic and inorganic matter to produce DBPs including HAAs. Acrylamide and its polymer enter drinking water because they are used in the production of flocculants for the clarification of potable water and in the treatment of municipal and industrial effluents.

We developed a single method to address the requirements for acrylamide and the newly regulated haloacidic acids. The direct injection method allows the analysis of 9 haloacidic acids and acrylamide in 8 min and achieves LOQs far below the requirements with 10 µl injection volume. Details and performance tests of the method can be found here.

Bromate, Chlorate and Chlorite

These parameters belong to the DBPs formed during the water treatment process. When ozone is used to disinfect water intended for human consumption, it reacts with naturally occurring bromide to bromate. The disinfection of chlorine dioxide forms chlorate and chlorite.

In the EU DWD all three are regulated and can be analysed together with perchlorate in a 5 min method on the new Anionic Polar Pesticides Column. For more information please follow this link.

PFAS

Perfluoroalkyl substances (PFASs) are found in a range of consumer goods and industrial processes. Due to their ubiquitous nature and possible toxicity they were classified as persistent organic pollutants (POPs) within the Stockholm Convention back in 2009. Now they are regulated in the EU DWD with a sum and a total parameter. We developed a direct injection method for 39 PFAS analytes of different groups also including replacement compounds for the most common PFOS and PFOA that reaches lower concentration at the ng/L level. Detailed information is given in the webinar or read in the app note.

Unispray for PFAS

Unispray, special designed MS source shows significant increases to response and S/N values for PFAS compounds, hence improving the overall sensitivity of the system (see application note here). Additional information on the application as well as on possible sample preparation procedures for PFAS can be found on the Waters PFAS website.

Microcystine LR

Cyanobacteria (blue-green algae) are found in freshwater environment produce secondary metabolites such as microcystines that are toxic to higher organisms. These water-soluble heptapeptides can enter the drinking water treatment process. The most common MC-LR is therefore regulated and needs to be measured when there is a potential algae bloom in the source water.

A method that was developed to quantify 10 well-known cyanotoxins including MC-LR was developed. Prof. Christine Edwards from Robert Gordan University speaks about the “Challenges of Microcystin Analysis” in this webinar.

Pesticides

The classic application is a direct injection method with pos-neg-switching for multiresidues. The corresponding LC, MS and processing methods for over 500 pesticides can be downloaded from our Quanpedia Database.

There are groups of pesticides that need a bit more attention, such as acidic herbicides and more polar pesticides or transformation products. The acidic herbicides have been addressed in a dedicated app note. For diquat and paraquat a HILIC method was published as well as a method describing FMOC derivatization for glyphosate, glufosinate and AMPA. Glyphosate & Co. is currently also subject to an evaluation of a direct injection method on the Anionic Polar Pesticide Column.