BRIEF COMPARISON OF LCESIMS AND LCAPCIMS Wenjie Cao

BRIEF COMPARISON OF LC-ESI-MS AND LC-APCI-MS Wenjie Cao SABIC Technology Center Riyadh, Saudi Arabia

Less background in APCI 1 st difference Courtesy of Shimazu. com Heater in APCI 2 nd Proton Exchange and Ion “Evaporation” 3 rd No. 1

A CLOSER LOOK OF APCI IONIZATION Courtesy of LGC. com No. 2

BRIEF COMPARISON OF ESI AND APCI Pros and Cons of ESI and APCI ESI Ionization Pros Cons Multiple charged ions for Could be difficult in high MW chemicals MS interpretation "Evaporate" Metal ion for ions out of confirmation of M? droplets Lower Temperature Metal adducts May mess up with MRM APCI Ionization Pros Cons Less sensitive or Easier to get M+1 for can't handle identification ionic chemicals No multiple-charged Gas Phase ions, easier for Proton identification Exchange No metal ions, easier for identification More background ions Easier for MRM Ion suppression Neater background Good for thermally unstable chemicals More adducts and clusters Less cluster/adduct ions Thermally unstable chemicals? Can't handle higher flow rate Higher Temperature Can ionize less polar chemicals Can handle higher LCflow rate No. 3

LC FLOW RATE FOR ESI AND APCI Courtesy of F. Klink No. 4

ION SUPPRESSON IN ESI AND APCI Courtesy of LGC. com No. 5

BACKGROUND ADDUCT IONS OF ESI OVER APCI AT “THE SAME LC-MS CONDITIONS” ESI APCI No. 6

BACKGROUND ADDUCT IONS OF ESI OVER APCI AT “THE SAME CONDITION” ESI APCI No. 7

CHROMATOGRAMS OF ESI AND APCI AT “THE SAME LC-MS CONDITIONS” ESI APCI No. 8

LC-MS CHROMATOGRAMS AND MS SPECTRA OF ESI AND APCI AT “THE SAME LC-MS CONDITIONS” W. J. Cao, 2014 APCI ESI No. 9

APCI-MS SCAN SPECTRUM OF DNBP W. J. Cao, 2014 No. 10

APCI PRODUCT IONS OF M+H+ W. J. Cao, 2014 READY FOR MRM No. 11

ESI-MS SCAN SPECTRUM OF DNBP AT THE “SAME CONDITION” W. J. Cao, 2014 MAY NOT BE ABLE TO DO FAST FIA OR INFUSION OPTIMIZATION No. 12

ESI PRODUCT ION SPECTRUM OF M+Na+ W. J. Cao, 2014 No. 13

AGILENT JET-STREAM ESI Courtesy of Agilent. com No. 14

AJS-ESI SPECTRUM OF DNBP W. J. Cao, 2014 Figure I. ESI produce many metal adduct ions which can’t be used for MRM analysis. No. 15

AJS-ESI PRODUCT IONs OF 2 M+Na+ At LOW CE W. J. Cao, 2014 No. 16

AJS-ESI PRODUCT IONS OF 2 M+Na+ At HIGHER CE W. J. Cao, 2014 No. 17

Characterization of Polymer Additives by LC-APCI-MSD Chromatogram of LC-UV @ 270 nm Strong UV adsorption indicates aromatic groups Chromatogram of LC-MSD (APCI +) No UV peaks, nice series No. 18

Characterization of Polymer Additives by LC-APCI-MS Dm=44 Nonylphenol Ethoxylates (NPE) Alkylphenol Ethoxylates (APE) No. 19

Characterization of Polymer Additives by LC-APCI-MSD Sorbitan Mono-Laurate Dm=28 Dm=42 Sorbitan Di-Laurate Wenjie Cao, 2007 No. 20

QUANTITATION BY UHPLC-APCI-MS/MS Wenjie Cao, November 2011 No. 21

QUANTITATION BY UHPLC-APCI-MS/MS Wenjie Cao, November 2011 No. 22

EI, ESI, CI, APCI, A TROUBLE SHOOTING STORY “PERFECT” REASONING WITH PUBLICATION BACKUP What is that 106 ion? No. 23

PERFECT REASONING, BUT FUNDAMENTALLY WRONG A TROUBLE SHOOTING STORY MISLEAD BY PUBLICATIONS No. 24

PERFECT REASONING, BUT FUNDAMENTALLY WRONG A TROUBLE SHOOTING STORY MISLEAD BY PUBLICATIONS No. 25

EI, ESI, CI, APCI, ONE MORE PUBLICATION ON APCI Use air in APCI? APCI needs “greater C of additives in mobile phase? No. 26

SUMMARY OF ESI AND APCI FOR LC-MS Summary of Pros and Cons of ESI and APCI ESI Pros Cons * Can't handle chemicals Multiple charged ions for Could be difficult in MS Proton exchange, easier to which can’t do protonhigh MW chemicals interpretation get M+1, M-1 exchange. Metal ions for confirmation of M? Ionic chemicals Popular, more publications and references Low T, good for thermally unstable chemicals No multiple-charged ions, Metal adducts easier for identification No metal ions, easier for May mess up with MRM identification Ion suppression could be more serious Less ion suppression More background ions, No metal ions to mess up noisy baseline MRM MW range is usually less than 1500 More matrix dependent Neater background Less good publications and references. More adducts and clusters Can't handle high flow rate Ion suppression could be more serious High T, Less cluster/adduct ions Can ionize less polar chemicals High T, can handle higher LC-flow rate * may not be APCI issues Thermally unstable chemicals No. 27

THANK YOU! QUESTIONS? No. 28