2400 Series 2 CHNS/O Analyser

1. 2400 Series 2CHNS/O Analyser Paul Gabbott PETA

2. Page 2

3. Page 3 Organic Elemental Analysis • The PE 2400 CHNS/O Elemental Analyzer is a combustion technique that determines weight percent carbon, hydrogen, nitrogen, sulfur or oxygen in a variety of sample types • Capable of operating in 3 modes; CHN, CHNS and Oxygen

4. Page 4 Organic Elemental Analysis • The 2400 is an organic elemental analyser • It is designed to analyser organic materials such as those produced in a chemical laboratory • It is not designed for inorganicseg carbon in steel • Nor is it a TOC analyser (total organic carbon). In some instances the 2400 could act as a TOC but it is not designed to continuously handle applications such as TOC in seawater

5. Page 5 How does it work ? • Combustion technique – • Typically a sample is weighed into a tin capsule and placed in the autosampler carousel. • Information is entered into the instrument (ID & wt) and the run started. • The sample is combusted into simple gases, CO2, H2O and N2, collected in the mixing chamber, separated by frontal chromatography and measured by TC

6. 2400 Design Schematic Combustion Zone Gas Control Zone Separation Detection Page 6

7. Combustion Process • Completely combusting a weighed sample is critical to obtaining accurate results • Static and Dynamic • 4 steps to combustion • Sample introduced into oxygen environment • Additional oxygen introduced • Allowed to sit and burn • Additional oxygen introduced • Operator programmable Page 7

8. CHN Combustion Tube

9. Page 9 Combustion Tube • Ultra high gases and pure quality reagents are required Oxidizing & Removes interferences i.e.,halogens and sulfur Aids in the combustion of the sample Prevents unwanted elements from interfering with the analysis and keeps the system cleaner

10. CHN Reduction Tube

11. Combustion and Reduction Packing • Combustion Tube • Silver Vanadate • Silver Tungstate • EA-1000 • Reduction Tube • Copper 60-80 mesh • Pack the Copper as tight as you can • Cuprox • Copper Plug • Leave about ¼ inch space from top of copper plug and the top of the tube

12. Reduction Tube • Removes excess oxygen • Reduces NOX to Nitrogen • Copper oxide at the end converts any CO to CO2 • Operates at about 640°C (the best temp is often debated)

13. Consumables Consumables are supplied individually or in kits • N241-0680 CHN • Combustion Kit • 2 Combustion tubes & Chemicals 2000 runs • N241-0681 CHN • Reduction tube Kit • 2 tubes 500 runs total

14. Gas Control Zone • Homogenous mixture of product gases will achieve the highest precision Constant temperature, volume and pressure maintained in the mixing chamber Environmental conditions such as changes in barometric pressure do not affect results Achieve highest precision Separates the combustion area from the separation area , so we can change the amount of O2 without change in retention times Mechanical mixing Ensures a homogenous mixture of product gases Page 14

15. Page 15 Separation Frontal Chromatography Steady State Signal Simple difference calculation determines signal Easier to calculate a small step change than a small peak

16. Page 16 Frontal Chromatography

17. Page 17 Modes of Operation • CHN mode is the most universal of the analysis • CHN mode has the best reagent design and allows use of the Optimize Combustion control parameters. • Interfering elements (halogens and sulphur) are removed. • CHNS mode designed to include sulphur, which reduces universality. This includes limiting the range of sample types and sample size (1 to 2 mgs recommended). Metal cations are excluded. • Special care must be used in calibration and blanks for lower levels of sulphur. • The Oxygen mode where oxygen in a sample is converted to carbon monoxide over platinised carbon. • This mode excludes compounds containing phosphorous, fluorine, silicon and metal cations. Samples containing mineral matter must be demineralised prior to analysis. • Upgradeability The user may choose any or all modes. The 2400 Series II may be freely upgraded at any time to add additional mode capability to suit the needs of the laboratory.

18. Sulphur • CHNS is determined in a similar manner to CHN • Sulphur separates after water so gives a step after water • This gives a longer analysis time • However the combustion tube is completely different

19. Sulphur Tube Operating temperature around 975°C

20. Sulphur tube • Sulphur burns to SO3 and SO2 • The SO3 must be removed (reduced) immediately because of its reactivity • This is achieved by adding copper to the combustion tube • Normal catalysts are replaced with EA 6000 because they scrub for sulphur • Dynamic combustion conditions are required, and this restricts the use of the ability to extend combustion time or add extra oxygen • CHNS does not use a separate reduction tube

21. Oxygen Analysis • Oxygen is converted to carbon monoxide over platinised carbon in a helium gas stream using silver capsules. • Helium / hydrogen (approx 5%) gas stream enhances conversion to CO and allows the use of tin capsules. • Copper is used to convert any CO2 formed back to CO • Acid gases are scrubbed in a trap installed on the side of the analyser

22. Oxygen Tubes

23. Trap used with oxygen

24. Oxygen detection

25. Oxygen applications • Often involve coals or fuels • Note that coals must be demineralised for which procedures exist, but it is not as simple.

26. CHNS and O2 • CHNS Tubes • Copper • EA-6000 Oxygen Tubes Copper

27. Page 27 Analysis Times • Analysis times CHN: 6 min, CHNS: 8 min, Oxygen: 4 min • Sample size 0 to 3 mgs typically depending on sample type. Small samples will generally be limited by weighing errors, but may be used. Large samples may be used if the combustible content is low • Analytical Element Range (mgs) • detector range • C 0.001 - 3.6 S 0.001 - 2.0 • H 0.001 - 1.0 O 0.001 - 2.0 • N 0.001 - 6.0

28. Page 28 Capabilities of EA 2400 Data Manager • Collect and store complete run information • Search stored runs • Create reports • 21 CFR part 11 compliant option • audit trail • signature points • permissions • Complete analyzer history stored • Instrument messages • Leak test output • Timing events • Monitored components • Advanced calculations • Statistics • Recalculation capabilities • Archive data

29. Page 29 EA 2400 Data Manager Main Run Window

30. Page 30 Queries • Specify your search using • AND/OR statements on • sample ID • date • operator • project • run type • mode • Set limits like • is • contains • does not contain • starts with • between • before • after • on

31. Page 31 Advanced calculations and Statistics • Advanced calculations provide additional information on results • Statistics can be preformed on a set of runs

32. Page 32 Printing reports and exporting data • Print • Table • Report template • Save to a file • RTF • TXT • PDF • Export formats • Excel • CSV

33. Page 33 Diagnostics • For confidence in instrument performance and for easy evaluation of instrument history the operator can send vital information to the database, including • Instrument status • temperatures • pressures • detector signals • voltages • Leak test results • Parameter settings • Purge times

34. Page 34 21 CFR part 11 compliance

35. Page 35 EA 2400 CHNS/O Analyzer • Unique technology features and newest most modern Data Manager Software

36. Page 36 EA 2400 CHNS/O Analyzer • Operating the system • Purging the analyser • Blanks • Conditioners • K-Factors • Samples

37. CHNS and CHN Purge Gases • Gases : Helium and O2 @ 99.995 % • N2 or Air for the Pneumatics @ 99.95 to 99.99%

38. Page 38 Purging prior to analysis • The analyser uses helium as a purge gas and oxygen as a combustion gas • Purge gases contain amounts of carbon, hydrogen and nitrogen which need to be determined. • In addition contaminants from the atmosphere get into the instrument and gas lines, particularly overnight and when the system is left unused. • Purging is required to make sure the analyser and gas lines are free of contamination before starting. • The longer the gas lines the longer the purge times • Oxygen is used only as required so the oxygen lines are more prone to contamination when the system is unused

39. Page 39 System Purging • Helium purge • Use as long as found necessary to purge the analyser • Afterwards a series of helium blanks can be performed to ensure the analyser is free of contaminants • Oxygen Purge • Oxygen purging will pass through the copper tube and can cause a significant loss in lifetime of the copper • Oxygen purging should be kept to a minimum • The end of the combustion tube may be loosened to allow oxygen escape before the reduction tube. • Gas Lines • These must be copper or steel and completely free of leaks. Any leaks will seriously compromise performance. As a result gas lines must be connected straight to a cylinder and not used by any other equipment whatsoever.

40. Leak tests • Leak Tests • #1 Mixing Volume • #2 Combustion /Auto-Injector • #3 Column/Detector • Must pass Leak test 1 • Pressure should get to 760 mm, you will here a click around 730mm. Pressure will hold for 5 min’s @ 760 mm. • Test 2 will pressure around 780 to 800 mm, you may get a small drop in pressure +/- 2 mm • If this fails Check for Cracked tubes, Auto-injector o-rings

41. Leak Tests • Leak test 3 adds the detector and column • Cap sensing vent • Sensing vent is the peek tubing a yellow heat shirk tubing on it

42. Page 42 Blanks • Blanks consist of running the system without any sample to determine background levels of contamination. These are then subtracted from the sample values. • Tin (and all other) capsules contain levels of impurities which must be measured so need to be included. • Full oxygen blanks contain everything except a sample • They use up copper at a high rate so should be kept to a minimum • Helium blanks are run without oxygen or a capsule and are used to make sure the system is purged, stable and ready to be used. They do not use up chemicals so can be used freely.

43. Page 43 Conditioners • Blanks decondition the system by removing adsorbed water from internal surfaces • A series of blanks will therefore continuously reduce the hydrogen background value • Any sample run afterwards will show lower levels of hydrogen than it should because some of the water will be used to re-establish the adsorbed water equilibrium. • As a result a conditioner must be run after a blank. • Normally this is a sample of the reference standard • It does not have to be weighed because no use will be made of the result, but normally this is good practice to make sure a sensible amount is used, (eg – 2mg similar to a sample)

44. Blank Values Blank values are determined from a running average of three blanks interspersed with conditioners. The system automatically averages the results unless blanks are run sequentially The manual makes the following comments

45. Page 45 K Factors • K Factors are the calibration factors determined for each element by running known standards. • The step height of the signal for each element is measured in microvolts per microgram (or whatever units the software uses) of element present. • Sample response divided by the K Factor allows the amount of each element to be determined. This is converted to a weight percent when the weight is known.

46. K Factors K factors are determined from the running average of three or more values. Typical values as given by the manual are shown below.

47. Page 47 K-factors • K-Factors • should be run periodically to account for any drift or instability in the system. • Standards used • Should be appropriate to the samples being run • Eg if a 5% nitrogen standard is run with a 50% sample any error will be magnified 10 times • Different standards can be used for different elements if required.

48. Page 48 Typical Sart-up Sequence • Check Leak tests • 5 Helium blanks • Conditioner • Blank • Conditioner • Blank • Conditioner • Blank • Conditioner • 3 K-Factors • Samples

49. Page 49 Samples • Solid samples are encapsulated in tin foil capsules which are folded manually using a pair of tweezers • Care must be taken not to tare the foil or lose sample in this process • This is one of the most important and time consuming aspects of analysis

50. Weighing Samples • Samples need to be weighed to at least six figures (microgram) level • weighing accuracy of a 1mg sample weighed to 6 figures is +/- 0.1% • weighing accuracy of a 1mg sample weighed to 5 figures is +/- 1%