Analyzing Phenyl Ureas and Carbamates with HPLC/API-MS. Presented by Chen-Kai Meng, Ph.D. Applications Chemist

Transcription

1 Analyzing Phenyl Ureas and Carbamates with HPLC/API-MS Presented by Chen-Kai Meng, Ph.D. Applications Chemist

2 Outline Overview of ESI, APPI, and APCI sources Comparing ESI, APPI, and APCI results Identifying compounds with the same MW Quad CID (Collision Induced Dissociation) Trap MS/MS (AutoMS^2 and MS^3) Dial , Chairperson John Vis for e-seminar Audio Slide 2

3 Outline Overview of ESI, APPI, and APCI sources Comparing ESI, APPI, and APCI results Identifying compounds with the same MW Quad CID (Collision Induced Dissociation) Trap MS/MS (AutoMS^2 and MS^3) Dial , Chairperson John Vis for e-seminar Audio Slide 3

4 Relative Applicability of Atmospheric Pressure Ionization Techniques Dial , Chairperson John Vis for e-seminar Audio Slide 4

5 ESI Source HPLC inlet Nebulizer gas inlet Nebulizer Capillary Nebulizer tip aimed at 90 to inlet of MS Waste heated N 2 Countercurrent gas for efficient evaporation and desolvation Dial , Chairperson John Vis for e-seminar Audio Slide 5

6 ESI Process Charged Droplets Analyte Ion Evaporation - - de/dr = 10 9 V/cm Rayleigh Limit Reached Coulombic Explosions - - Solvent Ion Cluster Analyte Ion Dial , Chairperson John Vis for e-seminar Audio Slide 6

7 Dr. John Fenn Nobel Lecture Dial , Chairperson John Vis for e-seminar Audio Slide 7

8 Nebulizing the Sample Nebulizing nitrogen Polymeric Damping Mechanism Rigid stainless steel eluent delivery capillary Micromachined tip Dial , Chairperson John Vis for e-seminar Audio Slide 8

9 ESI Droplets Distribution Agilent LC/MSD Our sprayer design leads to smaller and more uniform droplets Amount Some competitive designs Spray Droplet Size Dial , Chairperson John Vis for e-seminar Audio Slide 9

10 ESI Source Design Ion capture zone Heated N 2 Cone design has small sweet spot for ion capture Flat field presented to ions in Agilent source gives a large sweet spot for ion capture plus heated N 2 repels uncharged species Slide 10 Dial , Chairperson John Vis for e-seminar Audio

11 Agilent 1100 LC/MSD, ESI Source Enhanced Sensitivity, Optimized Geometry Unique nebulizer and electrical field design require no X,Y, Z position adjustments - even when flow rate changes!! Dial , Chairperson John Vis for e-seminar Audio Slide 11

12 APCI Source HPLC inlet Nebulizer gas inlet Heater Capillary Corona needle heated N 2 Waste Dial , Chairperson John Vis for e-seminar Audio Slide 12

13 APCI Process Analyte containing aerosol Evaporation DISCHARGE Charge transferred to analyte Vapor Charged reagent gas formed Analyte ions Dial , Chairperson John Vis for e-seminar Audio Slide 13

14 Agilent 1100 LC/MSD APCI Source Corona Needle Ionize the gas with a discharge Dial , Chairperson John Vis for e-seminar Audio Slide 14

15 APPI Source Nebulizer Heater Capillary Ionizes gas phase analytes with light instead of a corona discharge Similar to PIDs for GC hν UV Lamp heated N 2 Waste Dial , Chairperson John Vis for e-seminar Audio Slide 15

16 APPI Process Direct ionization of analyte to radical cation Analyte containing aerosol Evaporation Vaporization of LC eluent hυ hυ Dopant is photoionized and acts as reagent gas Ionization of solvent or dopant with charge exchange to analyte Dial , Chairperson John Vis for e-seminar Audio Slide 16

17 Energetics for Photoionization lamp Krypton 10.0 and 10.6 ev Ionization Potentials Solvent Ionization Potentials Anthracene 7.4 ev Toluene 8.82 ev Fluoranthene 7.8 ev Acetone 9.70 ev Caffeine 8.0 ev 4-Nitrotoluene 9.5 ev 2,4,6-Trinitrotoluene ev Methanol Acetonitrile Water ev ev ev Dial , Chairperson John Vis for e-seminar Audio Slide 17

18 Agilent 1100 LC/MSD PPI Source Lamp Source (Krypton), instead of Discharge Needle Dial , Chairperson John Vis for e-seminar Audio Slide 18

19 Flow Rate Performance for APPI and APCI APCI versus APPI Response for Cortisol by Area Area /47 2.1/ / /1000 Column I.D./Flow Rate (µl/min) APCI APPI Zorbax SB-C mm columns in 1.0, 2.1, 3.0 or 4.6 mm i.d. Isocratic elution with 80% methanol in water at 47, 208, 425 or 1000 µl/min depending on column i.d. Data were collected on the LC/MSD in SIM mode. Dial , Chairperson John Vis for e-seminar Audio Slide 19

20 Positive Ion FIA in THF:H2O or IPA:H2O Compounds: MW ESI APCI APPI Analgesics Aspirin Ibuprofen Acetaminophen Naproxen Caffeine PAH s anthracene benzo(a)anthracene benzo(ghi)perylene benzo(a)pyrene naphthalene Vitamins A D E K C Conditions: 0.4 ml/min, 100 picomoles injected Key: not seen weak good signal Dial , Chairperson John Vis for e-seminar Audio Slide 20

21 Break Number 1 Please type your question into the Chat Box at any time during the presentation. Dial , Chairperson John Vis for e-seminar Audio Slide 21

22 Outline Overview of ESI, APPI, and APCI sources Comparing ESI, APPI, and APCI results Identifying compounds with the same MW Quad CID (Collision Induced Dissociation) Trap MS/MS (AutoMS^2 and MS^3) Dial , Chairperson John Vis for e-seminar Audio Slide 22

23 Carbamates and Phenyl Ureas Methomyl 162 Fenuron 164 Propham 179 Monuron 198 Carbaryl 201 Diuron 232 Aminocarb 208 Fluometuron 232 Propoxur 209 Siduron 232 Chlopropham 213 Linuron 248 Oxamyl 219 Neburon 274 Swep Carbofuran Mexacarbate 222 Methiocarb 225 Barban 257 Dial , Chairperson John Vis for e-seminar Audio Slide 23

24 LC/MSD Method Parameters ESI APCI APPI Solvent A H 2 O, 0.1% acetic acid H 2 O H 2 O Solvent B ACN, 0.1% acetic acid ACN MeOH Post column n/a n/a 40 µl/min Acetone Solvent gradient B: B: (hold 6min) Inj. Volume 2 µl 2 µl 2 µl Column (30 o C) Zobrax Eclipse XDB-C8 4.6 x 50 mm, 3.5 µm (p/n ) Col. Flow 1 ml/min 1 ml/min 1 ml/min Frag 60 V 110 V 110 V Vcap 3500 V 4500 V 4500 V Dry gas 12 L/min 11 L/min 11 L/min nebulizer 60 psi 35 psi 35 psi Vaporizer n/a 225 C 225 C dry gas temp 350 C 275 C 275 C Dial , Chairperson John Vis for e-seminar Audio Slide 24

25 Don t use ACN as Mobile Phase for APPI H 2 O/ACN (noisy baseline) min H 2 O/MeOH min Dial , Chairperson John Vis for e-seminar Audio Slide 25

26 Acetone (dopant) needed in APPI Without post-column Acetone (poor signal) min With 40 µl/min post-column Acetone min Dial , Chairperson John Vis for e-seminar Audio Slide 26

27 API Results (20 ng on column) MSD1 TIC, MS File (CAS\020304A\UREA0042.D) APPI, Pos, Scan, Frag: 110 APPI MSD1 TIC, MS File (CAS\020304A\UREA0050.D) APCI, Pos, Scan, Frag: 110 APCI MSD1 TIC, MS File (F:\UREA0225\M D) API-ES, Pos, Scan, Frag: 60, "pos scn" ESI min min min Dial , Chairperson John Vis for e-seminar Audio Slide 27

28 Baseline noise MSD1 SPC, time=14.991: of CAS\020304A\UREA0042.D Max: MSD1 SPC, time=14.975: of CAS\020304A\UREA0050.D Max: 3155 m/z MSD1 SPC, time=14.940: of F:\UREA0225\M D Max: m/z m/z APPI APCI ESI Slide Dial , Chairperson John Vis for e-seminar Audio

29 Signal-to-Noise Ratio (Scan mode) ESI is better for Carbamate analysis APPI is better for Phenyl urea analysis ESI APPI APCI Carbofuran Mexacarbate Diuron Monuron (Carbamate) (Phenyl urea) Dial , Chairperson John Vis for e-seminar Audio Slide 29

30 Break Number 2 Please type your question into the Chat Box at any time during the presentation. Dial , Chairperson John Vis for e-seminar Audio Slide 30

31 Outline Overview of ESI, APPI, and APCI sources Comparing ESI, APPI, and APCI results Identifying compounds with the same MW Quad CID (Collision Induced Dissociation) Trap MS/MS (AutoMS^2 and MS^3) Dial , Chairperson John Vis for e-seminar Audio Slide 31

32 AP Electrospray LC/MSD HPLC inlet Nebulizer gas inlet Nebulizer Skimmers Lenses HED detector Capillary Octopole Quadrupole Waste heated N 2 Fragmentation zone (CID) Molecular fragmentation by ion collisions with nitrogen molecules Controlled via a single ion optics parameter -- "fragmentor voltage" Dial , Chairperson John Vis for e-seminar Audio Slide 32

33 Example of CID Fluometuron, MW=232 F F F 213 NH 188 O N CH 3 CH Frag = 75 V Max: e Frag = 225 V Max: m/z m/z Dial , Chairperson John Vis for e-seminar Audio Slide 33

34 Example of CID Frag V. 175 V Fluometuron, MW= V 225 V 250 V 275 V Dial , Chairperson John Vis for e-seminar Audio Slide 34

35 Example of CID H 3 C CH 3 N Cl Cl Diuron, MW= O NH Frag = 75 V Max: e m/z Frag = 200 V Max: m/z Dial , Chairperson John Vis for e-seminar Audio Slide 35

36 Example of CID Diuron, MW=232 Frag V. 175 V 200 V 225 V 250 V 275 V Dial , Chairperson John Vis for e-seminar Audio Slide 36

37 Outline Overview of ESI, APPI, and APCI sources Comparing ESI, APPI, and APCI results Identifying compounds with the same MW Quad CID (Collision Induced Dissociation) Trap MS/MS (AutoMS^2 and MS^3) Dial , Chairperson John Vis for e-seminar Audio Slide 37

38 AutoMS^2, the first 233 peak O Cl F F F NH N CH 3 CH H 3 C CH 3 N O NH Cl This mass 72 fragment is common to both Fluometuron and Diuron Dial , Chairperson John Vis for e-seminar Audio Slide 38

39 AutoMS^2, the second 233 peak Cl 72 H 3 C CH 3 N O NH Cl All three precursors (233, 235, and 237) gave the same mass 72 fragment. Dial , Chairperson John Vis for e-seminar Audio Slide 39

40 AutoMS^2, the third 233 peak 114 O Siduron, MW=232 NH NH CH Can we confirm the mass 94 and 137 fragments? Dial , Chairperson John Vis for e-seminar Audio Slide 40

41 AutoMS^3, the third 233 peak is part of peak 137. Dial , Chairperson John Vis for e-seminar Audio Slide 41

42 Fragments from Siduron 114 O Siduron, MW=232 MS2 NH NH CH MS3 Dial , Chairperson John Vis for e-seminar Audio Slide 42

43 Summary In APPI, don t use Acetonitrile (use Methanol) and add Acetone (or Toluene) post-column as dopant Phenyl Ureas respond better in APPI, Carbamates respond better in ESI AutoMS^n (Trap) and CID (Quad) help to identify compounds with the same masses Reference: C. Kai Meng, Analyzing Phenyl Ureas and Carbamate Pesticides Using ESI-, APPI-, and APCI-LC/MSD, Agilent Application Note, Publication number EN. Slide 43 Dial , Chairperson John Vis for e-seminar Audio