2. Elemental, My Dear Watson Paul Middlestead University of Ottawa, G.G. Hatch Laboratory For 19th Continuous Flow Conference, Calgary, 2013

3.  This talk is for new users  We will touch the basics on Elemental analysers  A mix bag of tricks and advices  Refer to manufacturer’s instruction manuals  Only endorsed products are: Rickards Red and Rickards White Who/what is this talk for?

4. Meet my family Combustion EA NCHS TC/EA Pyrolysis HO Large capacity S onlyTOCStable isotopes 1500 0 C1200 0 C

5.  Leco is the most popular manufacturer of elemental analysers. Every department has one or two of those accumulating dust.  Static combustion using oxygen: not suitable for IRMS Meet Grand Pa

6. Elemental Analyser as an…instrument Schematics Autosamplers Flash combustion Chemicals & Configurations Gas Chromatography Thermal Conductivity Detector Typical run Common problems EA-IRMS Let’s touch on

7.  Simultaneous determination of Nitrogen, Carbon, Hydrogen, Sulfur, Oxygen  Measuring range: 100 ppm to 100%  Sample size: 0.1 to 1000 mg / 0.1 to 25 ul  Detection limit: 10 ppm  Accuracy: 0.3% - 0.02% absolute EA as an …. instrument

8.  CE instruments (Carlo Erba) models 1108, 1110, NA 1500, NA 2100, Flash 1112  Costech Model ECS4010  Elementar cube family  Eurovector models EuroEa3028-HT, Ea3024- IRMS, pyrolysis model  Sercon-Integra  TC\EA Thermo  … Manufacturers, models blablabla

9. EA : Bulk analysis of NCHS/O  Organic compounds  Pharmaceuticals  Organometallics  Petrochemicals  Gasoline & fuels  Graphite  Carbides & nitrides  Metals & alloys  Polymers  Explosives  Hydrocarbons  Soils  Coal & coke  Liquids In short, you can combust your grandmother!

10. Ref gas 1 Elemental Analyser (CNS) (OH) Interface Isotope Ratio Mass Spectrometer He Ref gas 2 2 m Typical EA setup with IRMS

11. EA picture

12. Elemental Analyser Schematic TCD Combustion Chemicals 1020C Reduction Chemicals 650C Gas chromatography Column in oven Thermal Conduc- tivity Detector Autosampler N2 H2O CO2 SO2 He O 2 Water Trap EA line out

13. Found the problem with the previous slide? A beer if you do… (5 seconds)

14. Elemental Analyser Schematic TCD Combustion Chemicals 1020C Reduction Chemicals 700C Gas chromatography Column in oven Thermocouple Detector Autosampler N2 H2O CO2 SO2 He O 2 Water Trap EA line out

15. A cold Rickard’s Red for me please.

16. 1. Sample/Std is weighed and wrapped in tin foil, placed in culture tray/autosampler 2. Sample drops is flash-combusted in O 2 in He stream, causing rapid cracking and oxidation of gases stoichiometrically equivalent to their elemental components, some gas oxides need to be reduced before obtaining final products (N 2, CO 2, H 2 O, SO 2 ) i.e. oxidation and reducing reactions involved Typical Analysis Procedure for EA

17. 3.Separation of gases by gas chromatography or chemical column traps 4.Detection by thermal conductivity detector (TCD) or IRMS. 5.Curve made from weighing certified stds (for isotope and/or quantitative measurements)

18. Some torture tools…

19. Well well, got culture?

20. Super size meSuper size meSuper size meSuper size me

21. MAIS C’EST IMPOSSIBLE!

22. C’EST FANTASTIQUE! Filters? Careful!

23. Not flat please

25. Autosamplers (AS128)

26. Autosamplers (AS200)

27. Zero Blank

28. Zero Blank modified

29. Special tools required ECS 4010

30. Take 20 minutes to study the gas schematics of your instrument Be good to yourself

32. Loop concept (a) OXYGEN OUT He 99.996 SAMPLE LOOP 10, 5, 3 ML O 2 99.998 TO AUTOSAMPLER He only

33. Loop concept (b) He SAMPLE LOOP 10, 5, 3 ML O2O2 TO AUTOSAMPLER He + O 2 + He OXYGENOUT

34. Sample dropping 0 103040 START Sample drops Combustion starts Injected O 2 Flash should occur within 2-3 seconds of being dropped 20 seconds

35. PLATINUM: Absorbs much of the heat of the reactor before passing it on to the sample, slowing down reaction PLATINUM: Absorbs much of the heat of the reactor before passing it on to the sample, slowing down reaction ALUMINIUM: Supplies good oxidation flash and prime sample ignition but does not melt or mix with the sample thus does not promote inner oxidation ALUMINIUM: Supplies good oxidation flash and prime sample ignition but does not melt or mix with the sample thus does not promote inner oxidation SILVER: Melts at 960 0 C, does not take part in the combustion, retains trace of carbon when in molten state SILVER: Melts at 960 0 C, does not take part in the combustion, retains trace of carbon when in molten state TIN: Inexpensive & takes active part in process. Melts at 235 0 C with very low enthalpy, intermixes with organic and inorganic substances, expedites the final oxidation reaction TIN: Inexpensive & takes active part in process. Melts at 235 0 C with very low enthalpy, intermixes with organic and inorganic substances, expedites the final oxidation reaction Why you Tin man?

36.  Increases local temperature from 1020 0 C to 1700- 1800 0 C, accelerating combustion  Cancels the endothermic effects of tin melting (0.14 calories required for melting vs 11.96 calories given off during flash)  Equalizes the thermal degradation of any substance  Uses available oxygen immediately and requires less Dynamic Flash Combustion Oxidation of TIN gives a tremendous enthalpy reaction Sn + O 2 SnO 2 + 142 000 cal 235 0 C 1700-1800C

37.  Ensures that sample oxidation is performed in gaseous phase (95%) rather than in the catalytic reactions  Breaks down any matrix without combustion aid  Converts the sample into a homogenous, quantitative combustion gas mixture (unfractionated)  Provides a gaseous plug for the entry into the GC column  Forms tin oxide, an oxidation catalyst  Provides visual indication of the reaction Dynamic Flash Combustion Oxidation of TIN gives a tremendous enthalpy reaction

38. C CO 2 CO 2 C CO 2 CO 2 Let’s get cracking H H 2 OH 2 O S SO 2 + SO 3 SO 2 Combustion tube Reduction tube N N 2 + NxOx N 2

39. Chemicals and Configurations System should be optimized for element(s) to be analyzed One-tube system: both oxidant catalyst and reducing chemicals in one tube; usually used if S is to be analyzed Two-tube system: one tube for oxidant, one tube for reducing chemicals; usually used for N, NC or NCH Chemical traps: Mg Perchlorate or Anhydrone will trap H 2 O, and Carbosorb will trap CO 2 (and SO 2 )

40. Configuration CN

41. Configuration S

43. Small is beautiful

44. Using grinding tools and diluted Nitric acid, one can re-use combustion and reduction tubes More torture tools

45.  Gas chromatographic columns will separate different components according to their polarity and molecular size.  Factors influencing the quality of the chromatography: column length, size of packing, tube diameter, stationary phase type, flow rate, temperature.  Packed column: packed polymer beads, different sizes available. High capacity, low resolution.  Capillary column: small capillary with polymeric film on inner wall. High resolution, low capacity.  Deactivated fused silica is free of adsorption problems encountered with most packings or capillaries columns. Gas Chromatography

46. Gas Separation/ GC He + N 2, CO 2, H 2 O, SO 2 + He He + SO 2 + H 2 O + CO 2 + N 2 + He INCREASING POLARITY OF GASES

47. What after we separate? He + SO 2 + H 2 O + CO 2 + N 2 + He DETECTOR TIME DETECTOR N2N2 CO 2 SO 2 H20H20

48. Gas Separation / Purge & Trap TCD SO 2 H2OH2O CO 2

49. Thermal conductivity detector (TCD) Heated filament from which heat is removed at a constant rate by He gas stream. Change in heat transfer is caused by presence of analyte molecules with different thermal conductivities than He. Relatively low sensitivity, excellent range and linearity. Non-destructive. Electron capture detector (ECD) Electrons are captured by organic species in ionized carrier; used for trace sulfur determination. Isotope Ratio Mass Spectrometer (IRMS) Detectors

50. TCD schematic

51. Typical output of EA, text book N2 CO2 H2O SO2

52. Balance: Get the best A 0.01mg readability translates in an error of 0.25% on a 2 mg sample (say on 100% carbon) A 0.01mg readability translates in an error of 0.25% on a 2 mg sample (say on 100% carbon) Balance

53. IAEA (and NIST) standards Links available on Isogeochem

54.  Best : %N, 15 N, %C, 13 C  Test different materials and pray  Make your own:  Caffeine  L-glutamic acid  Mixtures such as sucrose + potassium nitrate  Mix in solution of natural + enriched/depleted material then dried, powdered, sieved STD: Making it on your own…

55. STD: Not making it on your own…

56. Can also contact other university labs to buy or obtain their internal standards. STD: Not making it on your own…

57. Calculation Methods 1. K-Factor ( Single point calibration with blank substraction) Calculated % = K * (Area unk – Area blk) Weight unk Where K = Weight std * Theor std % Area std - Area blk

58. Calculation Methods 2. Linear Fit (Least square linear regression) Calculated % = m * Area unk + b Weight unk Peak Area Wt * Th std %

59. Calculation Methods 3. Quadratic Fit (Least square quadratic regression) Calculated % = a * Area unk 2 + b * Area unk + c Weight unk Peak Area Wt * Th std %

60. An update… Most elemental analysers manufacturers have considerably refined their calculation methods, with more complex algorithms, low-high ranges and statistical tools.

61. Common Problems (I) CO2 Blank Unreproducible blank Contaminated capsules Wash or change batch Memory effect due to ashes Remove ashes N2 Blank Increasing blank values Copper exhausted Repack reduction tube High mass 30 Repack reduction tube

62. Common Problems (II) Very high blank values Autosampler purge off Very high mass 28 Switch on!! High & constant blank Impure oxygen High mass 28 Replace O2

63. Common Problems (III) No signal Detector off Switch on! Broken filament Call engineer Low carrier flow Check flow rate & blockage MS valve closed, open split problem Ghost/double peaks Leak Find and fix CO2 or H2O trap exhausted Replace packing of trap N2 ? CO2?

64. Common Problems (IV) Peak broadening Presence of dead volume Check trap(s) or packing Incomplete combustion Remove ashes, check drop time (flash), exhausted chemicals Baseline drift Leak Find and fix Carrier flow fluctuating Check GC oven temperature Outgassing of chemicals

65. Leak check or check leaks (1) EA Pressure check Cap exit port Increase P of He to 1.3 bar, wait 3 minutes Close regulator Pressure gauge should not move for 5 minutes EA Flow check (requires electronic mass flow controller) Cap exit port Monitor flow for 3 minutes Flow should drop to 0 ml/min

66. Leak check or check leaks (2) EA Inter- face Leak check with IRMS EA has been leak checked EA chemicals have outgassed (12 hours) Tune to Ar (mass 40) Should meet manufacturer’s requirements Use Ar cylinder to hunt MS Ar

67. Elemental Analyser Schematic for IRMS TCD Combustion tubeReduction tube Water trap Gas chromatography Column Thermocouple Detector Autosampler To MS N2 CO2 Interface Diluter & ref gas

68. Did you find the small error in the last slide? WAKE UP!

69. Elemental Analyser Schematic for IRMS TCD Combustion tubeReduction tube Water trap Gas chromatography Column Thermocouple Detector Autosampler To MS N2 CO2 Interface Diluter & ref gas

70.  Water is removed via Mg Perchlorate/sicapent trap ---water and mass spectrometer do not mix----  Configuration should be optimized for gas of interest  Leak free (mass 28 & 40, use Argon as leak probe)  Low and stable background (mass 28, 18, 40, 44)  Dynamic range must be respected, do use target beam  Best sequence is carefully planned ie known concentration of samples  Garbage in……Garbage out Considerations for EA-IRMS

71. Some useful info Lab No.Sample typeNitrogenCarbonHydrogenSulphurC/NComments 97-256-010Adult mysids10,2050,97na 5,00Whall JD, Trent U. 97-220-003 Amphipods 6,8133,205,660,004,88Pastershank G., U of O/ Biology 97-256-004Chironomids8,9837,23na 4,15Whall JD, Trent U. 97-256-014Clam12,3048,91na 3,98Whall JD, Trent U. 97-220-004 Clam muscle 11,2643,416,771,103,85Pastershank G., U of O/ Biology 97-220-005 Clam shell 0,0511,910,190,00 231,6 3 Pastershank G., U of O/ Biology 97-220-018 Cragon (shrimp) 10,0337,225,910,003,71Pastershank G., U of O/ Biology 97-220-020 Diatom 0,000,740,090,00N.A.Bad trace 97-220-002 Egg white 11,8545,836,931,143,87Pastershank G., U of O/ Biology 97-220-001 Egg yolk 5,4162,699,730,0011,59Pastershank G., U of O/ Biology 97-220-009 Fish bone 6,4319,533,510,003,04Pastershank G., U of O/ Biology 97-220-008 Fish eye 12,9048,707,052,133,77Pastershank G., U of O/ Biology 97-220-013 Fish fin 10,0134,365,350,003,43Pastershank G., U of O/ Biology 97-220-014 Fish gill 13,2847,107,060,003,55Pastershank G., U of O/ Biology 97-220-015 Fish gut content 9,5644,887,071,134,69Pastershank G., U of O/ Biology

72.  Best are quartz filters; they are stable. However they are more expensive and offer less choice.  Silver filters are great too.  Mostly glass filters, cheap, huge choice.  How much to use? Filters, we can do that!

73. Area =  *R 2 In this case, a punch is about 16mm 2 and our whole filter is about 1490mm 2. Our punch hole is roughly 1% of the filter.

74. Sediment contamination Inorganic Carbon Average  13 C: 0‰ = Total CarbonOrganic Carbon Average  13 C: -25‰ 0%+ 100%=-25 ‰ 1%+ 99%=-24.75 ‰ 5%+ 95%= -23.75 ‰ 10%+ 90%= -22.50 ‰ 50%+ 50%= -12.5 ‰

75. Honey, you think I’m fat? % NitrogenWt required 1000.1mg 101.0mg 55mg 27mg 110mg 0.1100mg 0.001Yeah, right! Optimal amount of Nitrogen: 0.1mg

76. Open split, magical stuff He + CO 2 + N 2 + He EA 100 ml/min Fused silica capillary 100 um, 2m, inserted about 30cm in EA line, 0.4 ml/min going into source of IRMS 2mm or 1/16” SS line from EA

77. In real life…Open split EA IRMS Ref 1 Ref 2 He Ref 3 Ref 4 Ref 5 Ref 6 Ref 7 Ref 8 Ref 9 Ref 10 Ref 11 Ref 12

78. In real life…Open split EA IRMS Ref 1 Ref 2 He Ref 3 Ref 4 Ref 5 Ref 6 Ref 7 Ref 8 Ref 9 Ref 10 Ref 11 Ref 12

79. The joy of sniffing EA only Mass spectrometer output TCD output from EA MagnetPeakjump N2N2 CO 2 Mass 28, 29 Mass 44,45,46

80. The joy of sniffing, total Mass spectrometer output TCD output from EA MagnetPeakjump N2N2 CO 2 Mass 28, 29 Mass 44,45,46 Masses 28 & 29Masses 44, 45 & 46

81. To dilute or Not to dilute?

82. Second last suggestion I strongly recommend that you create a basic document for your users explaining the limits and pitfalls of EA-IRMS analysis, this will save you (and your users) an enormous amount of time.

88.  Removing inorganic carbon is not trivial  Alkalies (Sodium, Potassium, Calcium) are difficult to combust, catalist is definitively required to bind and help with oxydation.  Oxygen contribution to  34 S is still a problem. Some unresolved issues with EA

89. Last suggestion and only Official Endorsement The only product fully and officially endorsed by the author is: Rickard’s Red

90. Thank you for not snoring My thanks to: Wendy Abdi, Nik Binder, Fred Longstaffe, Scott Hughes, Gilles St-Jean, Peter Stow and Patricia Wickham for the use of material, brain power and time …