> Boosting the performance of LC/MS/MS analysis of mycotoxins and their transformation products by use of innovative separation techniques

Transcription

1 > Boosting the performance of LC/MS/MS analysis of mycotoxins and their transformation products by use of innovative separation techniques Florian übner

2 > overview analytes of interest separation techniques first example T-2 and T-2 in human cells second example multi mycotoxin analysis third example determination of TA and TA metabolites summary 2

3 > analytes of interest mycotoxins deoxynivalenol (DN) 3-acetyldeoxynivalenol (3-Ac-DN) zearalenone (ZN) N 2 N 2 fumonisin B 1 (FB 1 ) fumonisin B 2 (FB 2 ) T-2 toxin (T-2) T-2 toxin (T-2) ochratoxin A (TA) N Cl 3

4 > analytes of interest discussed metabolites of TA N (S) N (S) Cl 9 1 (R) 3 10 C R/4S - hydroxy - ochratoxin A 9 1 (R) 3 10 C 3 11 ochratoxin A - hydrochinone N (S) Cl 9 1 (R) 3 10 C 3 11 ochratoxin A N (S) N (S) Cl (R) 10 (R) ochratoxin B 9 1 C 3 11 open-lactone-ochratoxin A C Cl 9 1 (R) 3 10 C 3 11 ochratoxin α 12 7 Cl 9 1 (R) 3 10 C 3 11 ochratoxin α glucuronide (S) N 7 Cl (R) 3 C 3 11 ochratoxin A glucuronide N (S) Cl 9 1 (S) C 2 11-hydroxy-ochratoxin A 4

5 > separation techniques ion mobility (AB SCIEX S SelexIN device) analyte and matrix ESI towards MS separation voltage (SV) compensation voltage (CV) 5

6 > separation techniques MRM³ Q1 collision cell Q3 ion-trap linear ion-trap product ion spectrum of m m 1 m 2 m 3 m 2a + m 2b + m 2c + 6

7 > separation techniques ekspert microlc 200 system micro-lc: flow-rate: µl/min injection volume: µl pressure: up to 600 bar column i.d.: mm improved performance: - better ionization during ESI - more focused peaks - faster separation 7

8 > 1 st example T-2 and T-2 on LC-MS 4000 QTRAP (AB SCIEX) ng/ml area: 152 T ng/ml area: T ng/ml area: ng/ml area: 4707 quantitation of T-2 and T-2 in cell culture studies column: Synergi Fusion RP18, 150 mm x 2 mm i.d.; 4 µm mobile phase: A: mm N 4 Ac B: ACN + 5 mm N 4 Ac fragments of [M+N 4 ] Time, 8.0 min

9 > 1 st example T-2 and T-2 on LC-MS QTRAP 5500 (AB SCIEX) ng/ml area: ng/ml area: ng/ml area: ng/ml area: quantitation of T-2 and T-2 in cell culture studies column: Synergi Fusion RP18, 150 mm x 2 mm i.d.; 4 µm mobile phase: A: mm N 4 Ac B: ACN + 5 mm N 4 Ac fragments of [M+N 4 ] + 9

10 > 1 st example T-2 and T-2 on microlc-ms QTRAP 5500 (AB SCIEX) T ng/ml area: ng/ml area: T ng/ml area: ng/ml area: quantitation of T-2 and T-2 in cell culture studies column: AL RP18, 100 mm x 0.5 mm i.d.; 2.7 µm mobile phase: A: % FA B: ACN % FA fragments of [M+Na]

11 > 1 st example summary 5500 QTRAP about 10 times more sensitive than QTRAP 4000 LC-MS system T-2 1 ng/ml T-2 10 ng/ml T ng/ml T-2 5 ng/ml 4000 QTRAP QTRAP 5500 QTRAP micro LC micro-lc system allows for 3 times faster runs while maintaining similar signal to noise levels 11

12 > 2 nd example basic goal for many mycotoxins maximum levels are decreed by European Law, e.g.: deoxynivalenol: µg/kg fumonisins (sum of FB 1 and FB 2 ): µg/kg ochratoxin A: (80) µg/kg zearalenone: µg/kg T-2 & T-2 toxin:? dilute and shoot -method preferred e.g. 10 g of sample + 20 ml of solvent (70% organic) supernatant diluted 1:5 (15% organic), PLC starting conditions filtrated if necessary and directly injected therefore the method should be suited for minimum levels of: 10 ng/ml for DN, 3-Ac-DN, FB 1 and FB 2 1 ng/ml for ZN 0.01 ng/ml for TA 12

13 > 2 nd example separation of eight mycotoxins on QTRAP e4 5.0e4 4.0e4 3.0e4 2.0e DN Ac-DN 4.18 FB 1 basic method mycotoxin standards: DN & 3-Ac-DN: 25 ng/ml FB 1, FB 2,T-2 & T-2: 5 ng/ml ZN: 2 ng/ml TA: 0.1 ng/ml 1.0e FB T T-2 ZN measured in negative ionization mode 5.52 TA 5.59 ZN column: Synergi Fusion RP18, 150 mm x 2 mm i.d.; 4 µm mobile phase: A: % FA B: Me % FA 13

14 > 2 nd example separation of eight mycotoxins on QTRAP e Ac-DN 8.0e4 6.0e4 4.0e FB FB 2 method directly transferred to a micro-lc system mycotoxin standards: DN & 3-Ac-DN: 25 ng/ml FB 1, FB 2,T-2 & T-2: 5 ng/ml ZN: 2 ng/ml TA: 0.1 ng/ml 2.0e e4 1.5e4 1.0e DN 1.64 T T TA 1.99 ZN column: AL RP18, 100 mm x 0.5 mm i.d.; 2.7 µm mobile phase: A: % FA B: ACN % FA

15 > 2 nd example separation of eight mycotoxins on QTRAP e5 1.2e5 8.0e4 4.0e Ac-DN 1.68 FB FB 1 optimized micro-lc method mycotoxin standards: DN & 3-Ac-DN: 10 ng/ml FB 1 & FB 2 : 5 ng/ml T-2, T-2 & ZN: 1 ng/ml TA: 0.01 ng/ml DN 1.77 T T TA 2.09 ZN column: AL RP18, 100 mm x 0.5 mm i.d.; 2.7 µm mobile phase: A: % FA B: ACN % FA

16 > 2 nd example summary very sensitive equipment allows for dilute and shoot methods even at very low concentrations needed for the determination of TA most important mycotoxin contaminants in grains and grain products can be analyzed in a 4 min PLC run 16

17 > 3 rd example TA exposition adults Mean consumption analyzed TA levels (g/person/day) (µg/kg) nonalcoholic beer 21.3 <LD 0.08 beer <LD 0.29 wine and grape juice <LD 7.00 coffee <LD 6.32 bread <LD 5.54 pasta <LD chocolates and sweets <LD 3.60 breakfast cereals <LD sausages <LD 4.56 Source: Directorate-general ealth and Consumer protection, European Commission, SCP, Task Assessment of the dietary intake of ochratoxin A by the population of the EU member states,

18 > 3 rd example analysis of urine samples on QTRAP 5500 intensity, [cps] 9.0e4 7.5e4 5.0e4 2.5e4 TA 1 ng/ml in urine (spiked sample) m/z 404, N Cl C open lactone TA-glucuronide 2 ng/ml in urine (spiked sample) m/z N Cl C

19 > 3 rd example tuning of DMS (SelexIN) 9000 Tα TB parameters: - separation voltage - modifier - gas flow - temperature P-Tαglucuronide P-TAglucuronide TA 4-TA P-TA compensation voltage CV [V] separation voltage: 2700 V; DMS temperature: 300 C (high); modifier: methanol; modifier composition: 132 µl/min (low); offset:

20 > 3 rd example reduction of background signals using DMS Intensity, cps 9.0e4 7.5e4 5.0e4 2.5e4 TA 1 ng/ml in urine (spiked sample) m/z 404, Max. 9.0e4 cps Time, min Intensity, cps 1.8e4 1.5e4 1.0e4 using DMS signal intensity lowered by a factor of 5 background signal lowered by a factor of Max. 1.8e4 cps Time, min 20

21 > 3 rd example fragmentation of open lactone TA glucuronide - cleavage of glucuronic acid in the collision cell N Cl fragmentation in the linear ion-trap (Q3) C 3 21

22 > 3 rd example improving selectivity by using MRM³ open lactone TA glucuronide 2 ng/ml in urine (spiked sample) m/z P-TA-glucuronide MRM e6 2.0e6 1.0e6 open lactone TA glucuronide 2 ng/ml in Urin (dotiert) m/z P-TA-glucuronide MRM

23 > summary while dilute and shoot methods are often convenient, there is a lack of selectivity caused by co-elution of matrix compensation of lacking selectivity can be achieved by innovative separation techniques for example MRM³ and ion mobility can be used for a more selective isolation of analytes use of a micro-lc system is not only faster and due to much less consumption of solvents more friendly to the environment, but can also boost the performance of methods by more focused peaks thus improving signal to noise ratios 23

24 > acknowledgments Prof. Dr. ans-ulrich umpf and Dr. Benedikt Cramer Maria Weidner and Katharina von Bargen (PhD students) Julian Dopstadt and Irina Schimanowski (MSc) and AB SCIEX for support 24