Food Analysis Applications with Triple Quadrupole LC/MS and TOF LC/MS

Transcription

1 Food Analysis Applications with Triple Quadrupole LC/MS and TOF LC/MS Linda Côté Application Specialist Page 1 1) Banned Antibiotics substances in food 2) Pesticides Residues screening in Food Page 2 1

2 MRM (Multiple Reaction Monitoring) Quad Mass Filter (Q1) Quad Mass Filter (Q3) Collision Cell Single MS with background ions (from ESI) Q1 lets only target ion 21 pass through 21 Collision cell breaks ion 21 apart Q3 monitors only characteristic fragments 158 and 191 from ion 21 for quant and qual Page 3 Banned Substance Analysis by LC/MS Triple Quadrupole and Time-of-flight Background Chloramphenicol by LC/MS/MS Nitrofurans by LC/MS/MS Malachite green by LC/MS/MS Trenbolone by LC/TOF MS Page 4 2

3 RASFF Notifications 24 (Veterinary drugs/member States and Third Countries) RASFF: Rapid Alert System for Food and Feed (European Union) Page 5 RASFF Notifications 25 (Veterinary drugs/member States and Third Countries) Page 6 3

4 Decision 22/657/EC Substance Chloramphenicol Medroxyprogesterone acetate Nitrofuran metabolites: furazolidone furaltadone nitrofurantoin nitrofuranzone Σ malachite/leuco malachite green Matrix Meat Eggs Milk Urine Aquaculture products Honey Pig kidney fat Poultry meat Aquaculture products Aquaculture products MRPL.3 µg/kg 1 µg/kg 1 µg/kg for all 2 µg/kg MRPL = minimum required performance limit Page 7 Decision 23/181/EC Substance Chloramphenicol Medroxyprogesterone acetate Nitrofuran metabolites: furazolidone furaltadone nitrofurantoin nitrofuranzone Σ malachite/leuco malachite green Matrix Meat Eggs Milk Urine Aquaculture products Honey Pig kidney fat Poultry meat Aquaculture products Aquaculture products MRPL.3 µg/kg 1 µg/kg 1 µg/kg for all 2 µg/kg MRPL = minimum required performance limit Page 8 4

5 The Identification Point (IP) System MS Technique IP / ion Low resolution mass spectrometry (LR-MS) LR-MS n precursor ion LR-MS n transition products High resolution mass spectrometry (HR-MS) HR-MS n precursor ion HR-MS n transition products Ions are needed when using GC/MS or LC/MS but only 2 transitions when applying LC-MS/MS Page 9 Chloramphenicol Page 1 5

6 Background Chloramphenicol (CAP) is a broad spectrum antibiotic CAP can cause aplastic anaemia Chloramphenicol big issue facing international seafood trade Banned from foods European community, Japan and the United States European MRPL accepted Worldwide as action level Page 11 Chloramphenicol structure * * OH * H N Cl Cl O 2 N O * OH * m/z CAP 257 Qualifier ion 152 Quantitiation ion CAP-d * Indicates positions of Deuterium for Internal Standard CAP-d5 MW of CAP = 322 MW of CAP-d5 = 327 Page 12 6

7 Sample Prep Agilent AccuBond SPE ENV PS DVB Carts (Part No ) Water Sample* Water Ethyl acetate Page 13 Page 14 7

8 Table1. LC/MS conditions HPLC Column Zorbax SB- C18, 2.1 5mm, 1.8um (p/n ) Flow rate.4 ml/min Mobile phase A: water B: methanol Gradient -5min, 3-7% B 5-6min, 7-1% B 8min 1% B Post time 4 min Temp 45 deg. C injection 5 µl MS Source settings Source ESI Ion polarity Negative Drying Gas temp. 35 deg. C Drying gas flow 1 L/min rate Nebulizer 45 psi Vcap 35 V Fragmentor 1 V Collision energy 1 V for m/z 321>257(qualifier ion) 15 V for m/z 321>152 (quantitation ion) Page 15 MS/MS of CAP at CE 1 and 15 V x x Product Ion (1.826 min) (321. -> **) Product ion _1V.d Abundance vs. Mass-to-Charge (m/z) - Product Ion (1.818 min) (321. -> **) Product ion _15V.d Abundance vs. Mass-to-Charge (m/z) V 15 V Page 16 8

9 Chloramphenicol - 5 Levels, 5 Levels Used, 5 Points, 5 Points Used, QCs Relative Concentration Chloramphenicol - 6 Levels, 6 Levels Used, 6 Points, 6 Points Used, QCs Relative Concentration Chloramphenicol - 5 Levels, 5 Levels Used, 5 Points, 5 Points Used, QCs Relative Concentration Chloramphenicol - 5 Levels, 5 Levels Used, 5 Points, 5 Points Used, QCs Relative Concentration Linearity of Method in Matrices Relative Responses y = * x R^2 = Relative Responses y = * x R^2 = Solvent Honey Relative Responses y = * x R^2 = Relative Responses y = * x +.15 R^2 = Shrimp Chicken Page 17 Ion ratios for CAP and Internal Standard - MRM (321. -> 152.) 321 -> 152., 257. Abundance x MRM (326. -> 157.) Abundance x A B Abundance Abundance x Ratio=46.8 C Acquisition Time (min) 326 -> 157., x1 1 Ratio= D Acquisition Time (min) Acquisition Time (min) Acquisition Time (min) Page 18 9

10 Repeatability.1 ppb CAP in Honey chloramphenicol d5-chloramphenicol Quantitative ion ( ) Qualifier ion ( ) Ratio Quantitative ion ( ) Qualifier ion ( ) Ratio RSD 8.11% 8.3% 5.91% 7.67% 9.99% 4.83% Page 19 Performance SENSITIVITY LINEARITY REPRODUCIBILITY RUGGEDNESS Page 2 1

11 Ease-of-Use Autotune that really works Only two or three parameters to optimize Fragmentor Collision Energy Maybe Vcap No adjustments on spray because of large production of small uniform droplets Mass Hunter Acquisition, Quantitation and Qualitative Data Processing Software Page 21 Nitrofurans Page 22 11

12 Nitrofurans - Background The four drugs furazoidone, furaltadone, nitrofurazone and introfurantoin are veterinary drugs that belong to family of nitrofuran antibiotics Widely used for the treatment of gastrointestinal infections in cattle, pigs and poultry The European Union (EU) banned the use of nitrofuran antibiotics in food-producing animals by listing them in Annex of Council Regulation 2377/9 The EU set a Minimum Required Performance Limit (MRPL) of 1 ug/kg (1 ppb) that laboratories should at least detect and confirm Page 23 Tolerances of Relative Intensities Rel. intensity (% of base peak) GC-MS/EI GC-MS/CI, GC-MS/MS n LC-MS, LC-MS-MS n > 5 % ± 1 % ± 2 % > 2 % - 5 % ± 15 % ± 25 % > 1 % - 2 % ± 2 % ± 3 % 1 % ± 5 % ± 5 % Page 24 12

13 MRM EIC of Nitrofuran Metabolites (1 ppt) AOZ AMOZ SEM AHD Page 25 Spike Nitrofuran Metabolites in Tilapia (1 ppt) AMOZ AOZ Spike SEM AHD Blank Page 26 13

14 Calibration Curves of Nitrofuran Metabolites AMOZ SEM R 2 >.999 R 2 >.998 AHD Linear range: 1 ppt 1 ppb or.5 to 5 pg on-column AOZ R 2 >.998 R 2 >.995 Page 27 The Reproducibility of Nitrofuran Metabolites Compounds AMOZ (m/z > 291.4) SEM (m/z 29.1 > 166.3) AHD (m/z > 134.3) AOZ (m/z 236. > 134.3) Concentration (ng/ml) RSD 1 (%) From 8 replicate injections. Page 28 14

15 Malachite Green Page 29 Malachite Green (MG) Among other veterinary drugs, the triphenyl-methane dye malachite green (MG) is a popular substance, and prevents fungal and parasitic infections in aquaculture, including saprolegniasis,, white spot disease, and ciliates. MG is prevalently reduced into leuco-malachite green (LMG) and deposited in fatty tissue of the fish. H C N C N reduction N Cl N Malachite Green (Green) Leucomalachite Green (Colorless) Page 3 15

16 Analytical approaches for determination of residues of MG HPLC equipped with a post-column unit for oxidation of LMG and with either an absorbance or MS detector for detection in Trout (eggs,, fry and muscle), catfish (muscle and plasma) and in Trout muscle. The reactors r (5 cm 4 4 mm) used in these studies were filled with 25% PbO 2 Other method LC-APCI APCI-MS in Catfish and Trout without the use of a reactor for the conversion of LMG. This study aimed at the development and validation of a procedure for sample processing and of an HPLC analysis a method for determination of residues of MG The use of LC ESI ESI-MS MS analysis was explored for confirmation of detected residues of this drug in such matrices. Sample preparation is fundamentally similar to nitrofurans except no derivatization required. Again, control spikes added post-extraction. Page 31 Calibration Curves Malachite Green Leucomalachite Green R 2 >.999 R 2 >.999 Linear range: 1 ppt 1 ppb or.1 to 1 pg on-column Page 32 16

17 MRM EIC of MG and LMG (1 ppt) MG 1 ppt LMG 1 ppt Blank Page 33 The Reproducibility of MG and LMG Compounds Malachite Green (m/z > 313.3) Leucomalachite Green (m/z > 239.2) Concentration (ng/ml).1.1 RSD 1 (%) From 8 replicate injections. Page 34 17

18 Marco Blokland, Paul Zoontjes, Saskia Sterk, Leen Van Ginkel THE USE OF LC-TOF IN RESIDUE ANALYSIS Page 35 Proposal Measurement of an exact mass within 5 ppm of a reference standard equals 2 points In practice The exact mass of two ions has to be measured within 5 ppm of a reference standard. The ratio of these ions should be within the criteria as laid down in the 22/657 Page 36 18

19 Use of these criteria to confirm the identity of trenbolone in spiked urine samples As model compound trenbolone was used to examine the use of exact mass for confirmation analysis trenbolone OH Structure formula: C 18 H 22 O 2 Exact mass: Protonated molecule: O Page 37 Chromatography with Rapid Resolution and Mass Spectrum of α & β- Trenbolone Page 38 19

20 Standards in Solvent 1. ng (n=1).5 ng (n=1).1 ng (n=1) Number < 3 ppm Avarage ratio 17α-Trenbolone % 19.2% 1.3% % Uncertainty (SD) Number < 3 ppm Avarage ratio Uncertainty (SD) Number < 3 ppm Avarage ratio Uncertainty (SD) 18.2% 7.8% 17ß-Trenbolone %.5% 14.6% 1.% % 3.3% Note: at 5 ng all were below 3 ppm Page 39 Results of 2 Bovine Urine Samples 17α-Trenbolone Ratio 271/253=18. <3 ppm <3 ppm Lower limit* 12.6 Upper limit* ß-Trenbolone Ratio 271/253=12.9 <3 <3 ppm ppm Lower limit* 9.1 Upper Limit* 16.8 Ratio IP Ratio IP Page 4 2

21 Conclusions of confirmation analysis With LC-TOF 2 samples of the 2 could be confirmed for α-trenbolone and 17 of 2 for ß-trenbolone Explicit exact mass criteria can be a useful tool for confirmatory analysis LC/TOF MS would be very useful in screening and confirmation where highest sensitivity is not needed and the ability to detect non-target compounds is important Page 41 1) Banned Antibiotics substances in food 2) Pesticides Residues screening in Food Page 42 21

22 Triple Quadrupole Screening with Confirmation Monitoring Labs need Robust screening with less than 5 % false negative Fast analysis Confirmation on positives LC/MS/MS requires Short dwell times Many analytes Two transitions for each analyte Reproducible retention times Reproducible ion ratios Page 43 LC Conditions Column: Agilent ZORBAX Eclipse XDB C-8, 4.6x15 mm, 5-µm, (p/n ). Column temp: 25 C Mobile phase: A = Acetonitrile, B=.1% formic acid in water Flow-rate:.6 ml/min Gradient: 1% A at min 1% A at 5 min 1% A at 3 min Injection volumes: 1-5 µl Page 44 22

23 Mass Spectrometer Conditions Mode: Positive ESI using the Agilent G641AA Triple Quadrupole Mass Spectrometer Nebulizer: 4 psig Drying gas flow: 9 L/min V capillary: 4 V Drying gas temp: 35 C Q1 Resolution: unit Q2 Resolution: unit Fragmentor voltage: 7 V Collision energy: 5-25 V MRM: 1 transition for every compound Dwell time: 15 msec. Page 45 1 Pesticide Screen + MRM (282. -> 212.) mix1_1pg_5may.d x Abundance vs. Acquisition Time (min) Page 46 23

24 Linearity of Atrazine 5 4 y = x R 2 =.9988 Area Amount injected (pg) Page 47 MRM chromatogram of a spiked green pepper sample at 1 µg/kg. x x TIC MRM (** - > **) mix1_1pg_green pepper.d MRM (23. - > 199.) mix1_1pg_green pepper.d ( a) + MRM (44. - > 372.) mix1_1pg_green pepper.d x (b) Abundance vs. Acquisition Time (min) Product ion chromatograms for (a) dimethoate and (b) azoxystrobin Page 48 24

25 Conclusions of Triple Quadrupole Screening The Agilent 641 LC/MS Triple can easily perform multiresidue screening for large #s of compounds Sensitivity is excellent but there will be a limit to the number of compounds done This work showed feasibility A project is in progress to screen 3 pesticides with confirmation qualifier ion Page 49 Screening Pesticides with LC/MS TOF Accurate Mass provides added compound selectivity Higher resolution provides added interference selectivity Always full scan data Unlimited number of compounds can be screened Unknowns and non-targeted compounds detected and accurate mass can lead to identification Page 5 25

26 TOF Screening of Pesticides Same 1 pesticides tested Linearity and matrix suppression evaluated Database of 6 compounds created and used Screen using Molecular Feature Database Search Page 51 Comparison matrices for Imidacloprid 1.E+7 9.E+6 8.E+6 Intensity 7.E+6 6.E+6 5.E+6 4.E+6 3.E+6 Buffer Pepper Tomato Lettuce Cucumber 2.E+6 1.E+6.E Concentration (ppm) Overlay of standard curves for LC/MS TOF in 5 matrices. Page 52 26

27 Page 53 Molecular Feature Extractor Page 54 27

28 CSV file for 1 Compound Data Base Fragment Ion Page 55 Imazalil in Babyfood: Pear, Orange, and Banana Spectrum at 25 pg! m/z ppm accuracy Page 56 28

29 Isotope cluster of the m/z 297 ion and imazalil structure in a pear extract Cl O 1 37 Cl A+2 H 2 C N NH Cl 1 35 Cl A+4 Page 57 Blank pepper sample showing complexity of the sample ~3 accurate mass peaks were detected in this sample at signal to noise of 1:1 or greater. Page 58 29

30 Fungicide Example of a report from the molecular feature database search Page 59 Conclusions Agilent 621 LC/MS TOF Screens unlimited number of compounds Each compound must be validated for definitive screening Sensitivity is the same regardless of number of compounds screened * Unknowns can be detected and often identified by the accurate mass measurement Confirmation** can be included but sensitivity will be reduced *Triple quadrupole mass spectrometer will be more sensitive up to a limited number of compounds. That limit has not been definitively determined. **Confirmation by accurate mass still needs to be accepted by the regulatory bodies (see feature article Analytical Chemistry, October 26, and trenbolone confirmation by accurate mass (submitted to Analytical Chemistry) Page 6 3