Noora Perkola Finnish Environment Institute. Nordic MS Symposium November 9, 2011, Båstad, Sweden

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1 Noora Perkola Finnish Environment Institute Nordic MS Symposium November 9, 2011, Båstad, Sweden

2 Artificial Sweeteners Used as additives in various food products to replace sugar 4 non-caloric sweeteners Acesulfame Potassium (ACS-K) Saccharin (SAC) Cyclamate (cyclamic acid) (CYC) Sucralose (SCL)

3 1 TRC = Toronto Research Chemicals Inc. (North York, Ontario, Canada) 2 Ehrenstorfer = Dr. Ehrenstorfer-Schäfers (Augsburg, Germany) 3 ADI = Acceptable Daily Intake Table 1. Analytes; Properties and origin of the standards

4 Artificial Sweeteners in Environment ACS-K, SAC, CYC and SCL detected in environmental water samples Levels up to over 2 µg/l of ACS-K SAC and CYC ng/l SCL ng/l Loos et al, Journal of Chromatography A (2009) 1216: Scheurer et al, Anal Bioanal Chem (2009) 394:

5 Artificial Sweeteners in Environment Pass through human body and WWTPs SAC and CYC eliminated over 90 % ACS-K up to 41 %, SCL 20 % ACS-K and SCL tracers of domestic waste water Effects to aquatic ecosystems unknown Scheurer et al, Anal Bioanal Chem (2009) 394:

6 Artificial Sweeteners in Environment Pass through human body and WWTPs SAC and CYC eliminated over 90 % ACS-K up to 41 %, SCL 20 % ACS-K and SCL tracers of domestic waste water Effects to aquatic ecosystems unknown Scheurer et al, Anal Bioanal Chem (2009) 394:

7 Sample pretreatment Reversed phase SPE (Waters Oasis HLB and J.T. Baker Bakerbond SDB 1) and ion exchange SPE (Waters Oasis WAX and Oasis MAX) were tested Oasis WAX chosen possibility to have SCL in different extract (different concentration factor)

8 Sample pretreatment SPE procedure (Oasis WAX cartridges): Conditioning 10 ml MeOH + 5 ml H 2 O Load sample (ph 3.0) Wash with 2 ml 2 % HCOOH (aq) 1st elution 6 ml MeOH 2nd elution 6 ml 1 % NH 3 in MeOH Recoveries between 70 and 120 % with extraction volumes ml

9 Sample SPE (WAX) Evaporation ml ph 3.0 Add ISTD (d-acs-k, d- SCL, d-cyc, 13 C-SAC) Condition: 10 ml MeOH + 5 ml H 2 O Load Sample: 1 drop sec -1 Elute: 6 ml MeOH + 6 ml 1 % NH 3 (MeOH) To dryness Redissolve to H 2 O LC-MS/MS analysis Figure 1. Sample pretreatment procedure

10 LC separation Acquity UPLC Flow rate ml/min, Column T 40 C LC eluents A: 2 mm NH 4 OAc (aq); B: 2 mm NH 4 OAc (MeOH) Gradient: Initial: 99.9 % A 0.10 min: 99.9 % A min: 0.1 % A min: 99.9 % A

11 LC separation Comparison of HSS T3 1.8 µm 2.1 x 50 mm and BEH C µm 2.1 x 50 mm columns HSS: better retention for polar analytes longer retention times but less matrix interactions?

12 Figure 2. Chromatogram of standard solution of ACS-K (1), SAC (2), CYC (3) and SCL (4) with BEH C18 column (1a-4a) and HSS column (1b-4b).

13 % % 14-Oct-2011 chromtest_111014_21 Sm (Mn, 2x1) WAX, HSS : MRM of 6 Channels ES- 162 > 82 (acesulfame) 2.47e5 ACS-K 0 Time Oct WAX, HSS chromtest_111014_21 Sm (Mn, 2x1) 2: MRM of 3 Channels ES > 80 (cyclamate) e3 CYC Time Figure 3. Example: Chromatogram of river water sample

14 MS/MS analysis Xevo TQ MS ESI - MRM Table 2. Optimization of MS parameters

15 ESI- MS/MS LOQs for ACS-K, SAC, CYC and SCL 25 ng/l, 25 ng/l, 6.5 ng/l and 210 ng/l, respectively Sample volume 100 ml Extract volume 1.0 ml Matrix suppression % for ACS-K and SAC % for SCL Less than 20 % for CYC

16 Enhancing ionization MS optimization with matrix? Lower matrix effects in MeOH than in 1 % NH 3 (MeOH) More efficient wash step in SPE or clean-up for extract? Modificator to enhance ionization in ES?

17 IDMS Isotope Dilution Mass Spectrometry Mass labelled standards for all analytes d 4 -ACS-K d 11 -CYC d 6 -SCL 13 C 6 -SAC Quantification using labelled standards Reliable results despite low recoveries

18 Acknowledgements I wish to thank Waters Association of Maa- ja Vesitekniikan Tuki ry for financial support

19 Thank You!