e MS. Dilts,Waters Chromatography€¦ · · 2007-11-21Dilts,Waters Chromatography,MilfordMA,...
Transcript of e MS. Dilts,Waters Chromatography€¦ · · 2007-11-21Dilts,Waters Chromatography,MilfordMA,...
<=?6-o3 # =?Characterization of Degradation Products from Antioxidants in Polyolefins
utilizinga Photo Diode Array Detector coupled with a Particle Beam LC/MS.
Matthew J. Dilts,Waters Chromatography,MilfordMA, 01757
INTRODUCTION
The additivepackage for polyolefinscan be quite complex,including
componentssuchas antioxidants,antistats,slips,and pigments. It is important
forthe polymermanufacturerto be able to determinethe exactamountof each
additivecomponentpresent inthe polymerfor processingand longevityof the
processedmaterial. 1 The pharmaceuticaland food industriesare also under
mandate fromthe Food and Drug Administrationto analyze any packaging
materialwhichcomes intocontactwithany productssoldfor human
consumption.Specificallytheyare lookingfor materialswhich may have
undergone UV or thermaldegradationand leachedout of the polymeric
material.
,U_S_SLOUIn the past, analysisof additivepackageshas been performed usingsingle
wavelengthanalysisandwide bore chromatography.The additive packages
used in polyolefinmanufacturingare typicallynot complexthussingle
wavelengthchromatographicsystemsare sufficientfor the analysisof a clean
additivesample. However, ifdegradationof the additives has occurred,the
sampleextract may be quitecomplex,containingseveral degradationproducts
for each additivepresent inthe polyolefin. Thus itmay be very difficultto
separate the additivesfrom the degradationproductsin a sample usingwide
bore chromatography.
A betterway to analyze thesesampleswouldbe to use narrow bore
chromatographyin combinationwith a photodiodearray detectorand a
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ThermaBeam mass detector. Narrow bore columns provide the
chromatographer with a better means of separating coelluting peaks. Photo
diode array detection can provide minimal structural information about a
compound but is also suited for determining if a peak is homogenous or not.
The ThermaBeam particle beam interface coupled with a mass detector is suited
for structural determination since it is able to generate electron impact spectra.
Electron impact spectra are interpretable spectra which can be compared to
large commercially available spectral data bases. The combination of these two
detector technologies provides the analyst with the ability to identify the source
of polymer degradation products.
EXPERIMENTAL
This study will look at the resulting degradation products of various antioxidants
exposed to high temperatures and UV light. Specifically, we will look at the
degradation products of Isonox 129, Irganox 1010, Irganox 1076, and Irgafos
168. The samples will be separated by reverse phase chromatography on a
Waters TM Nova-Pak C18 column (2mm X 150mm) using the following liquid
chromatographic conditions:
Gradient conditions.
Solvent A: Water
Solvent B: Acetonitrile
Gradient: 60% to 100% B in 6 minutes hold for 20 minutes
Flow rate: 0.35 ml/min
Column temperature: 50C
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The mass detectionsystemused is a WatersTM Integritysystemwhich consists
of the followingequipment:
WatersTM Integrity.
ThermaBeamTM massdetector
:ed WatersTM 996 PhotoDiodeArrayDetector
616 SolventDeliverySystem
717 plusAutosampler
_o MillenniumTM 2010 data system
1. Nielson, Richard C., Journalof LiquidChromatography,Vol. 14, #3, 3-91
J
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let ,__, .... , ..... _ ........... ,,.._.._ .... • .,
,Polyolefincontainersare used for the•packaging of many food and drugproducts sold for human consumption.
Pharmaceutical and Food industries
Any compounds which may have leachedout
Complex: Antioxidants(hinderedphenols), antistats, slips, and pigments
_O
Single wavelength analysis
Coelution
•" : A:Better Way!
,-Narrow bore chromatography
_-PDA detection
,- Mass Detection
b_ective-q............_._j ,.. _
,_Chromatographically separate apolyolefin additivespackage by reversephase HPLC.
_-Showthe utilityof couplinga massdetector with a photodiode arraydetector.
,-Generate Electron Impact mass spectrafor polyolefin additives using particle
s
beam LC/MS.
What is Particle Beam? '
LC/MS interfacetechnique_,Two .maincomponents
• Aerosol generation: Nebulization
• Enrichment: Momentum SeparationPatented technique - ThermaBeam• Electron Impact (El) spectra• Structural information
• Molecular weight information
_'L. -library searchablespectra
_.MomentumSeparator
",4
P-Nebulizer
,. Integrity ---AutomatedInjection SystemControl MassDetection
and Data
2010
GradientHPLC
n===== PDA UV Detection
AutomatedMassDetectorTuning
Separation '
,-Waters NovaPak C18 column2mm x 150mm
Chromatography_ • Solvent .A:Water
• Solvent B: Acetonitrile
• 60%-100% B in 6 minutes hold for 20 minutes ata flow rate of 0.35ml/min
• Column heated to 50°C
File __Edit View Plot Options _indows_Applications Help
PDAMaxPIot of
sixAntioxidants
PDA Processin_ Method Additives MaxPIot PDA
SpectrumIndex Plot
sixAntioxidants
_.File __Edit._o
PDAMatch Results PurityResults for
BHTstandard
MaxImpurity
plot for BHT
3D CubeofAntioxidantstandard
SpectrumIndex Plot
for BHT andIrganox
1076
S Jeclrum Index - ADDITIVE S _
_Edit _Plot Help , _ ...
SpectrumIndex Plot of
Additivesample
SpectrumReview of BHT
degradationproduct
File Edit Plot _Derived Help ...New Library...Open Library...Delete Library...
Close LibraryAdd to Library ...._emovc from Library
I_atch against IL_ihra,_y Rnectral_Br uv IB II
_ Match Parameters... SearchLibraries
Triple PlotSearch result
for BHTdegradation
product
File Edit Options Help ',.. ....°_,
_ Purity ResultsM_.s.o=,a,M=_._.n_ _.... for Library
.', Search of BHTdegradation
product
_.File Edit Options Help
- Purity, ResultsRetention Time: 13.882 Minutes Peak: 5 of 6
Peak Limits: 13.61 5 to 14.448 Baseline-to-Baseline
PurityAngle: 0.47 Purity Threshold: 1.34
PDAMatch Results
Match ThresholdMatchSpectrUmNameLibrarYNameIdeal VVvlnRMs Peak Purity0.000 1.438 ano×1076 Additives PDA Yes 0.0000 Graphical
display
File Edit Plot '_Help
SpectrumIndex plot for
unknowndegradation
product
., Conclusions
_-Ableto chromatographicaly separateadditives standards ,and samples by reversephase HPLC
oo
_-Demonstrated the utility of coupling a PDAdetector with an mass detector
Able to genera!e library searchable I .spectra for add_t_ves_and their degradationproducts