SLIDE 1 Optimising Micropollutants Extraction for Analysis of Water Samples: Comparison of Different Solid Phase Materials and Liquid-Liquid Extraction
Frederic Leusch1, Erik Prochazka1, Benjamin Tan2, Stewart Carswell2, Peta Neale3 and Beate Escher3
1 Griffith University, Smart Water Research Centre 2 Queensland Health Forensic and Scientific Services 3 The University of Queensland – Entox
Bioassays and Risk Communication
20 June 2012
Urban Water Security Research Alliance
SLIDE 2
SLIDE 3 CHEMICALS IN THE ENVIRONMENT
- 63+ million chemicals with >100,000 in
commercial use + their transformation products
- There are simply too many chemicals out
there to quantify them one by one …
Class Agric. Indust. Urban Natural Pesticides X Pharmaceuticals and personal care products (PPCPs) X X Hormones X X Industrial compounds X X Metals and inorganics X X X
SLIDE 4 A ROLE FOR BIOANALYTICAL TOOLS
- Toxicity testing, and bioanalytical tools in
particular, can overcome some of the challenges of environmental monitoring
- Detect chemicals by their
effect, not their structure
– Non-target compounds – Transformation products – Mixture effects
- “Is there a needle in the
haystack?”
SLIDE 5 THE PROBLEM …
- Similar to chemical analysis, bioanalytical
tools require a water sample to be processed prior to analysis
– Filtration followed by solid phase extraction (SPE) to concentrate organic compounds
- Are there unintended consequences of
sample preparation?
– Are we losing important (toxic?) compounds?
SLIDE 6 EXTRACTION: A NECESSARY EVIL
Vwater Vextract enrichment
Solid phase extraction
volume of extract added to assay total volume of assay
dilution
relative enrichment factor REF = enrichment factorSPE X dilution factorassay
enrichment dilution
REF = 1 “original sample” REF = 1 “original sample”
Macova, Toze, Hodgers, Mueller, Bartkow, Escher (2011). Bioanalytical tools for the evaluation of organic micropollutants during sewage treatment, water recycling and drinking water generation. Water Research 45: 4238-4247.
SLIDE 7 EXTRACTION: A NECESSARY EVIL
Vwater Vextract enrichment
Solid phase extraction
volume of extract added to assay total volume of assay
dilution
relative enrichment factor REF = enrichment factorSPE X dilution factorassay
enrichment dilution
REF = 1 “original sample” REF = 1 “original sample”
Macova, Toze, Hodgers, Mueller, Bartkow, Escher (2011). Bioanalytical tools for the evaluation of organic micropollutants during sewage treatment, water recycling and drinking water generation. Water Research 45: 4238-4247.
SLIDE 8 PROJECT AIM
- Can we develop an extraction method that
minimizes chemical loss?
SLIDE 9
EXPERIMENTAL DESIGN: STAGE 1
1L 1L Mix of 263 compounds Mix of 263 compounds
Oasis HLB Bond Elut PPL Supel HLB Strata X Bond Elut GC Supel CC
179 pesticides @ 1 ug/L 84 pharmaceuticals @ 20 ng/L
pH 2 pH 2 pH 7 pH 7
ultrapure water
LLE EthA LLE MTBE
Chemical analysis (LC-MS/MS, GC-MS/MS)
Elute (MeOH, acetone/hexane), Evaporate Elute (MeOH, acetone/hexane), Evaporate Rotovap Rotovap
SLIDE 10
SPIKED COMPOUNDS
log Kow pKa
SLIDE 11 RESULTS – STAGE 1
NA NA NA NA
Oasis HLB Bond Elut PPL Supel HLB Strata X Bond Elut GC Supel CC LLE EthA LLE MTBE Oasis HLB Bond Elut PPL Supel HLB Strata X Bond Elut GC Supel CC LLE EthA LLE MTBE
SLIDE 12 CONCLUSIONS – STAGE 1
- LLE performed well on average, but …
– High variability – Lots of solvent (60% of sample, vs 1% with SPE) – Contaminants even from high-grade solvent
- SPE (HLB) was very effective
– Oasis HLB and Strata X performed best, but
- ther options performed well too
- SPE (carbon) poor overall, but …
– Fair recovery of a few compounds not well recovered by HLB
SLIDE 13 ULTRAPURE VS RIVER WATER
- Does organic matter (present in
environmental samples) interfere with extraction efficiency?
ultrapure water TOC = 0.15 mg/L tap water TOC = 2.05 mg/L river water TOC = 8.31 mg/L
SLIDE 14
EXPERIMENTAL DESIGN – STAGE 2
1L 1L Mix of 315 compounds Mix of 315 compounds
215 pesticides @ 0.8 ug/L 88 pharmaceuticals @ 30 ng/L
pH 2 pH 2 pH 7 pH 7
tap water
Chemical analysis (LC-MS/MS, GC-MS/MS)
12 EDCs @ 50 ng/L river water (filtered)
1L 1L
Oasis HLB Supel CC
1L 1L 1L 1L Elute (MeOH, acetone/hexane), Evaporate Elute (MeOH, acetone/hexane), Evaporate
SLIDE 15 RESULTS – STAGE 2
NA NA
SLIDE 16 CONCLUSIONS – STAGE 2
- With combined Oasis HLB and Supelco CC
– Excellent recovery of wide range of compounds in environmentally relevant matrices – Better recovery than with ultrapure water (keeper effect?)
– 2x more solvent in stacked mode – More complex process
SLIDE 17
RECOMMENDED PROTOCOL
pH 2 pH 2 SPE
HLB/CC
SPE
HLB/CC
Elute
(MeOH, acetone/hexane)
Elute
(MeOH, acetone/hexane)
Add keeper
(2 uL DMSO)
Add keeper
(2 uL DMSO)
Evaporate Evaporate 1L 1mL
SLIDE 18 FUTURE WORK
- Develop an empirical-based model to predict
the recovery of compounds on various SPE sorbents to predict recovery of untested compounds
- Important variables include
– Sorbent – Kow – Ionised / unionised
SLIDE 19 ACKNOWLEDGMENT
- This project was supported by the Urban
Water Security Research Alliance
- We thank Dr Nicole Knight, Steve Carter and
Vince Alberts for laboratory support
SLIDE 20
Urban Water Security Research Alliance THANK YOU www.urbanwateralliance.org.au
