Presentation on theme: "EVALUATION OF PYRO CUBE FOR DEUTERIUM OF HAIR By Paul Middlestead and Michelle Chartrand Ottawa University, G.G. Hatch Lab At the request of Paul Brooks,"— Presentation transcript:
EVALUATION OF PYRO CUBE FOR DEUTERIUM OF HAIR By Paul Middlestead and Michelle Chartrand Ottawa University, G.G. Hatch Lab At the request of Paul Brooks, thanks big guy Calgary, Asita 2013, 19 th edition and still going…
WHAT IS A PYROCUBE ?
From elementar: vario PYRO cube
Note: No endorsement from this guy. All manufacturers make products that (usually) deliver. In this case, the PYRO is an alternative to the TC/EA in our lab. Both systems are fine and well supported. The PYRO is newer on the market and this is a preliminary evaluation
Ceramic and Glassy carbon tubes : 30mm and 18mm Glassy carbon chips packing + soot Bottom feeder Purge and trap separation Crucible: 2,0 cm 3 + (400 samples) TCD + software + computer 120/80 samples heated caroussel (open, large holes) 125ml/min flow Furnace on steroids + brain Can be upgraded to CNS Sleep mode Ceramic and Glassy carbon tubes : 18mm and 12mm Glassy carbon chips packing Bottom feeder GC column separation 5A Crucible: 0,75 cm 3 (200 samples) No TCD, no software, no computer 30/50/100 samples caroussel (close, small holes) 80ml/min flow Furnace on steroids
Bottom feeder independant flush, 130ml/min More space between glassy carbon and ceramic Fresh He for CO desorption on chemical trap Bypass for Hydrogen mode TCD for % of H2 and Oxygen Carrier flow of 125ml/min He 2-3 mm TCD 25 ml/min 100 ml/min IRMS
Different modes, different packings O mode: CO column in line, H is ignored H-O mode: CO column in line H mode: No CO column in line
H mode reactor No CO column Glassy carbon chips Crucible Bottom connector Qtz wool Ag wool We found H- mode packing to work well in all modes
H-O mode reactor CO column Glassy carbon chips Crucible Bottom connector Qtz wool Carbon black Graphite felt Spacer
O mode reactor CO column Glassy carbon chips Crucible Bottom connector Qtz wool Carbon black Graphite felt Spacer
Bigger is better ? Larger tubes = more surface = less repacking Larger crucible = more area = less cruciblication Larger tubes = more surface = smaller peaks Larger tubes = more $$$$ but last longer…
Wake up! Have you noticed the major difference with the PYRO in H mode? Something unthinkable Something not usually seen or used Something unnatural for analytical reason Hint: no divorce
IRMS Bypass of CO column… No separation between CO and H2
Typical Pyro run H mode Flow: 125ml/min Peak width: 88s (80) Peak height: 7,0V (10,6) Peak area: 76 (93.5) No CO column! No soot
Typical Pyro run H mode, TCD OMG, this is so cool ! USELESS
For fun, O-mode only, TCD IGNORED !
Pyro linearity Hair, 0,051 to 1,000 mg
First: It is imperative to normalise using a decent spread of values for Deuterium analysis, best to bracket the samples with standards of similar matrix. For Deuterium, what standards?
Polyethylene foil IAEA-CH YES Oil NBS (?) Biotite NBS-30-66(?) Some hair now available from USGS: USGS 42: -78,5 USGS 43: -50,3 Water stds in Silver capillaries (thanks Ty) Sweet nothing KAOLINITE Kga-1: -58
Methodology for hair (or exchangeable material) AUTOSAMPLER
Light water (vsmow)Heavy water (vsmow)Difference HairWaterMeasured (vsmow) %= diff value*100 diff water JohnLight-86,6= (-86,6+58,6)*100/228 = 12,3% or 0,123 JohnHeavy-58,6 Hair – water exchanged True = measured-(percent * water) 1 - percent Final John LightTrue light = -86,6 - (0,123 * -212) 1 – 0,123 69,0 John HeavyTrue heavy = -58,6 – (0,123 * 16) 1 - 0,123 69,0
StandardDeuterium values (raw) PEF Light (-212)336,0 PEF Heavy (-16)335,6 PEF Off Bench336,4 Kga-1 Light (-212)398.1 Kga-1 Heavy (-16)400,5 Kga-1 Off Bench399,0 First, check the standards! NO EXCHANGE !!!!!
This PYRO curve is exactly as all others curves done on TC/EA
NBS-30 Biotite test: -61,4 -63 (-66) Just for fun Not bad, this is a tough cookie! Lets not split hairs!
Real hair test HairPercent exchanged TC/EA Percent exchanged Pyro John12,3%6,1% Paul12,9%7,4% Ringo11,2%7,3% George12,9%5,9% Diff with real value TC/EA Diff with real value Pyro 2,6-9,7 2,4-7,1 0,6-7,3 2,3-8,4 Samples back-exchanged with air in auto sampler
Pyro peak, in H mode, is about 80% of TC/EA Run time of Pyro is about 50% shorter (H-mode) Same calibration equations Pyro appears to be less linear, but better in low range Very comparable instruments Conclusion Higher output: faster running, less down time No zero blank auto sampler: back exchange of H
We would like to thank: Paul Brooks, Wendy Abdy, Patricia Wickham, Gilles St-Jean, Scott Hughes, Robin Sutka and the Gods of Pyrolisis.