Migration from coffee filter papers

Presentation of Diploma Thesis

Matthias Fellner

18.06.2010

Who drank coffee today?Who drank coffee today?

• Should you worry?

GoalsGoals• Characterize commercial available

Austrian coffee filter papers• Determine the migration of

certain substances into coffee by simulating with water or organic solvents

• Compare the results with safety limits and get a conclusion if the results call for further inquiry

SamplesSamples• 1 Melitta 2 Spar

Original Kaffeefilterbleached! (Spar)

• 3 Hofer 4 Clever Kaffee Kaffee-Filter

(Hofer) (Billa)

• 5 Brigitta 6 Schlecker AS Kaffeefilter Kaffeefilter(Zielpunkt) (Schlecker)

• 7 Aromata Structured Coffee Filter Papers (Lidl)

StandardsStandards• ISO: International Organization for

Standardization• CEN: Comité Européen de Normalisation• DIN: Deutsches Institut für Normung• ÖNORM: Austrian Standards Institute (formerly

Österreichisches Normungsinstitut) • TAPPI: Technical Association of the Pulp and

Paper Industry• SCAN: Scandinavian Pulp, Paper & Board Testing

Committee

Used Standard Methods Used Standard Methods (compendium)(compendium)

• DIN EN 645 Preparation of a cold water extract• DIN EN 647 Preparation of a hot water extract• DIN EN 920 Determination of dry matter content• DIN EN 20287 Determination of moisture content• DIN 53124 Determination of pH aqueous extracts• DIN EN 1541 Determination of formaldehyde• DIN 54603 Determination of glyoxal content

Cold and Hot Water Cold and Hot Water ExtractionExtraction

• Simulating coffee with water• Cold water extraction (cwe): 10g paper with

200ml water for 24h at room temperature (23°C)• Hot water extraction (hwe): 10g paper with 200ml

water for 2h at 80°C

A coffee filter paper (Size 4)A coffee filter paper (Size 4)• cost: ~1-2 cents per filter• weight: ~1,60 - 1,85g• contact area: 2,875 dm²• moisture content: 0,2 - 1,2%• dry matter cwe: 1 bleached: ~5000 mg/kg

2-7 unbleached: ~1500-2300 mg/kg

• dry matter hwe: 1 bleached: ~2700 mg/kg 2-7 unbleached: ~800-2400 mg/kg

• pH cwe: ~7,2-7,5 (blank 6,9)• pH hwe: ~7,0-7,4 (blank 6,7)

Potassium permanganatePotassium permanganatemethodmethod

Titrimetric determination of volatile and none volatile organic substances in an extract

1 Melitta, 2 Spar, 3 Hofer, 4 Billa, 5 Zielpunkt, 6 Schlecker, 7 Lidl

GlyoxalGlyoxal• Used for paper coatings or cellulose derivatives• Photometric measurement (405nm) of the

product of HMBT + Glyoxal

• Safety limit: 1,5 mg/dm²-> all samples

lower than that by a factor of

~1500-2500

GlyoxalGlyoxal• Test close to detection limit• Comparison extraction with 100ml to 200ml with

sample Nr. 6 - good result: – Absorbance nearly doubled– which means concentration is nearly the same

FormaldehydeFormaldehyde• Main source paper coatings (problem in 1960s),

monomer from Urea-Formaldehyde resins• Photometric measurement (410nm) of the

product of Formaldehyde + Acetylacetone• Safety limit: 1,0 mg/dm²

-> all samples lower than that by a factor of ~200-300

Pentachlorphenol (PCP)Pentachlorphenol (PCP)PCP has been used as a herbicide,

insecticide, fungicide, algaecide, disinfectant -> preserving wood

Very toxic: forbidden since 1989Safety limit: 2mg/kgOld method: Photometric test with 4-

amino-antipyrin showed no reproducible results -> gas chromatography necessary to confirm

Fraunhofer Institute for Fraunhofer Institute for Process Engineering and Process Engineering and

Packaging IVV Packaging IVV Freising - GermanyFreising - Germany

Scanning Electron MicroscopeScanning Electron Microscope

Bleached Filter (Nr. 1) 1mm Unbleached Filter (Nr. 4) 1mm

Bleached Filter (Nr. 1) 80μm Unbleached Filter (Nr. 4) 80μm

Headspace Gas Headspace Gas Chromatography Mass Chromatography Mass

SpectrometrySpectrometry• Sample in 15ml Vial + 150°C + 1bar• Gasphase analyzed with GC-MS• Identification with library and standards• Quantification tricky• Results: All filters seam to be clean,

except some smallpeaks which couldnot be identified

Headspace GC-MS ExamplesHeadspace GC-MS Examples

Filter 1 gas chromatogram: except airpeak (3,98) no big peaks

Same chromatogram: the small peaks couldn’t be identified with the library

Filter Package 1: more bigger peaks, some could be identified with the library and with measurement of standards

17,37 = benzaldehyde; 21,44 acetophenone -> printer’s ink?

X-ray fluorescence X-ray fluorescence spectroscopyspectroscopy

Results:• Filter Papers: Sometimes detectable

concentrations of Na, S, Cl and Ca but always under 0,3% -> questionable (contaminations from hands possible and too light elements)

• Filter Packages: Same but:– Fe, Cu, Sr 0,01-0,1%– Al 1-4% printer’s ink?– Si 1-5%– Ca 8-24% - CaCO3 filler material

MultimethodMultimethodExtraction with Accelerated Solvent

Extraction (ASE)GC-MS (Shimadzu QP-5000) Determination of:• Benzophenone• Diisopropylnaphthalene (DIPN)• Michler's ketone• Phthalates• Pentachlorphenol (PCP)

ASE + Sample PreparationASE + Sample Preparation• Preextraction with empty cartridge• Dichloromethane extraction

-> 3 times for 15 minutes at 100 bar and 80°C

• Direct GC-MS analysis with standards• Only PCP needs derivatization

Results PhthalatesResults PhthalatesNothing found at:Dimethylphthalat, Diethylphthalat, Diallylphthalat, Dipropylphthalat ,

Benzylbutylphthalat, Dicyclohexylphthalat, Diphenylphthalat, Didecylphthalat, Diisooctylphthalate, Diisodecylphthalat, Dioctylphthalate

Echelle Plasma Emissions Echelle Plasma Emissions GC Detector EPEDGC Detector EPED

• P/T (Purge-and-Trap) sampling system• EPED: GC Detector for sulfur and halogens

chlorine, bromine, fluor, iodine– Atomization of molecules at 8000K and

atmospheric pressure in a Helium plasma– Detection of emission lines with a

polychromator

Other results Multimethod Other results Multimethod and EPEDand EPED

• The lab work at both methods is done and the measuring is finished

• But the reprocessing of the data is not finalized to be presented

• So far nothing indicates any high concentrations of any concerning substances

ConclusionConclusion• No safety limits are exceeded at Formaldehyde,

Glyoxal (PCP pending)• Concentrations of Phthalates low, but concerning• No indication of toxic metals (Hg, Cd, Pb, Chrom

VI)• No indication of migration from

the packages• No indication that recycled paper

was used• Some results still open but so

far nothing to really worry

Thanks toThanks to

Research Division Food Chemistry• Ingrid Steiner• Kathrin Scharnhorst• Herbert Hafner

Product Safety and Analytics • Ludwig Gruber• Gerd Wolz

•Nicole Weise

•Dominik Fiedler

•Michael Barwitz

Thank you for your Thank you for your AttentionAttention