0 20 40 60 80 100 120 MET QUAD DPG TPA CMQ DA MPPA MBPA ACE CYC PFBA PFBS PFPA TFMSA MSA SACC CYT GAP ACP MIT 4-MTSC TSC TU SUC 5-FU CA Recovery (%) HLB positive negative zwitterionic neutral Niklas Köke, Daniel Zahn, Thomas P. Knepper, Tobias Frömel Hochschule Fresenius, University of Applied Sciences, Institute for Analytical Research (IFAR), Idstein, Germany | Corresponding author: [email protected] Evaluation of sample preparation methods for highly polar organic contaminants from aqueous matrices Introduction References: [1] Reemtsma, T. et al. Environmental Science & Technology 2016, 50, 10308-10315 [2] Schmidt, C. K.; Brauch, H.-J. Environmental Science & Technology 2008, 42, 6340 [3] Zahn, D. et al. Water Research 2016, 101, 292-299 Acknowledgement: This work has been funded by the BMBF (02WU1347B) in the frame of the collaborative international consortium WATERJPI2013 - PROMOTE of the Water Challenges for a Changing World Joint Programming Initiative (Water JPI) Pilot Call. Procedure Conclusion Method comparison Evaporation Recovery % = x spiked before -blank x spiked after ∗100% ME %= x spiked after -blank x standard ∗100% -100% Spike before enrichment Nucleodur HILIC 2x150 mm; 5 μm Tap water Surface water WWTP Effluent Solid phase extraction Evaporation ESI – QqQ Spike after enrichment pH: 8.06 Conductivity: 575 μS/cm TOC: 0.48 mg/mL DOC: 0.38 mg/mL pH: 7.33 Conductivity: 193 μS/cm TOC: 2.3 mg/mL DOC: 2.1 mg/mL pH: 6.91 Conductivity: 512 μS/cm TOC: 4.1 mg/mL DOC: 4.0 mg/mL • The developed methods are suitable to enrich a wide range of very polar organic substances • Neutral analytes, which are most problematic with mmSPE, can be enriched with the evaporation method • The developed methods are complementary to each other and to enrichment with HLB material, and thus may increase the range of organic micropollutants that can be analysed in aqueous matrices Highly polar organic contaminants are mobile (MOCs) in the water cycle because they are able to pass natural and artificial barriers. If they are persistent (PMOCs), dilution is the only way of concentration reduction, and thus these substances may reach raw and drinking waters in significant concentrations [1] . When PMOCs are present in high concentrations or toxic [2] , their presence in the water cycle may have adverse effects on aquatic organisms or on human health. The analysis of MOCs is exacerbated by the same physico- chemical properties that facilitate their mobility (e.g. low molecular mass and high polarity). The lack of suitable enrichment methods for MOCs from aqueous samples is a major problem in their trace analysis, and thus two independent methods, a multimodal solid phase extraction (mmSPE) method [3] and an evaporation method, were developed to facilitate the analysis of MOCs. • Tap water was enriched with a generic HLB (hydrophilic and lipophilic balanced) SPE material method and the mmSPE method • The mmSPE method shows higher recoveries (mean mmSPE: 52%; HLB: 21%) for the enrichment of MOCs 9 mbar; 45° C 52% 21% 0 20 40 60 80 100 120 140 MET QUAD DPG TPA CMQ DA MPPA MBPA ACE CYC PFBA PFBS PFPA TFMSA MSA SACC CYT GAP ACP MIT 4-MTSC TSC TU SUC 5-FU CA Evaporation recovery (%) 58% -100 -80 -60 -40 -20 0 20 40 60 Ion suppression/enhancement (%) Tap water Surface water WWTP Effluent Enrichment factor 20 0 20 40 60 80 100 120 140 MET QUAD DPG TPA CMQ DA MPPA MBPA ACE CYC PFBA PFBS PFPA TFMSA MSA SACC CYT GAP ACP MIT 4-MTSC TSC TU SUC 5-FU CA mmSPE recovery (%) positive negative neutral 50% -100 -80 -60 -40 -20 0 20 Ion suppression/enhancement (%) Tap water Surface water WWTP Effluent Enrichment factor 200 mmSPE method Evaporation method zwitterionic 30 (±5) mg of Weak Anion eXchange Weak Cation eXchange Graphatised Carbon Black 5% NH 4 OH in MeOH (1 mL) 2% formic acid in MeOH (1 mL) 20% CH 2 Cl 2 in MeOH (0.5 mL) ACN/H 2 O 95/5 (0.5 mL) N 2 N 2 50°C 50°C 0.45 μm 100 mL pH 5.5 200 fold enriched • Non-target screening of ground water sample enriched with all three enrichment methods • Analysis with HILIC-HRMS allows rough estimation of analyte hydrophilicity with retention time • Number of detected ions was highest for HLB • Mean and median retention time, and thus capability to enrich hydrophilic compounds increases in order HLB, Evaporation, and mmSPE • The highest number of high intensity ions (>10 7 ) were detected after enrichment with mmSPE • In total, 17 analytes were determined with the mmSPE method and 19 analytes for the evaporation method • Neutral analytes were most problematic for the mmSPE method • Mean recovery was 50% for the mmSPE and 58% for the evaporation method • A combination of both methods is able to enrich 84% of the model substances by a threshold of 30% • For the mmSPE method, matrix effects seem to correlate well with matrix TOC/DOC • For the evaporation method, the salt concentration appears to have a significant influence on matrix effects • Matrix effects for the evaporation method increase significantly if the enrichment factor is increased from 10 to 20 (data not shown) • Significance of matrix effects for the mmSPE method • Significance of matrix effects for the evaporation method < < < <