Aminopolyphosphonates (APPs) are widely increasingly used in detergents and as antiscalants in industry and household applications. This results in a considerable estimated emission volume of up to 18600 tons per year of phosphonates and their possible transformation products that enter surface waters in Europe via wastewater. While there is scientific consensus that APPs are primarily eliminated in WWTPs via sorption onto sewage sludge, recent studies underlined the need for further APP transformation studies, as glyphosate – a quite controversially discussed herbicide – was identified as a minor transformation product of the widely used diethylenetriamine penta(methylenephosphonate) (DTPMP).

In this work, a novel speciation analysis method for APPs and a broad range of different phosphorus-containing transformation products was developed by a rapid ion chromatographic (IC) separation of nine species in 205 seconds and elemental detection by inductively coupled plasma-triple quadrupole-mass spectrometry (ICP-TQ-MS). Eluent conditions were optimized and 150 mM ammonium nitrate solution at pH 9.2 with 300 µg/L DTPA showed an excellent separation. The addition of DTPA led to improved peak shapes, particularly for larger APPs, due to the complexation of free and stationary metal cations, which could not further intervene in the chromatographic separation. The employment of a broad five-step gradient unlocked the possibility of eluting species with low retention and high retention within a single chromatographic run, respectively, without relevant equilibration between chromatographic runs. Species-specific detection limits below 1 ppb of phosphorus were reached.

Due to the analytical difficulties posed by APPs, a plethora of different analytical methods have been developed. This method presents a fast, easy and sensitive quantification method for (poly)phosphonates. It therefore presents a valuable tool to further understand the environmental fate of APPs and their mechanisms of decomposition. To prove the method’s applicability, transformation experiments of DTPMP at environmental conditions were evaluated, and different transformation products and intermediates were identified and quantified at different time points with complete phosphorus recoveries.