Geavanceerde bepaling van water in poeders en vaste stoffen via geautomatiseerde Karl Fischer titratie. Peter van de Spreng 8 November 2011

Transcription

1 Geavanceerde bepaling van water in poeders en vaste stoffen via geautomatiseerde Karl Fischer titratie Peter van de Spreng 8 November 2011

2 Mettler Toledo Theory Agenda Types of water Which samples - Karl Fischer: Volumetry/Coulomtery - Stromboli (sample changer) Methods for water determination Givaudan Samples, Givaudan Why water determination? Method Results (LabX) Conclusion 1

3 Our Group METTLER TOLEDO is a global manufacturer and marketer of precision instruments for use in the laboratories, manufacturing, and food retailing. Worldwide presence employees Sales approx. USD 1.5 billion

4 Tiel Laboratory Pipettes Weighing ph Titration Thermal Analysis AutoChemistry Industry Weighing Packaging Retail Weighing Den Bosch Product inspection Manufacturer 3

5 Mettler Toledo Theory Agenda Types of water Which samples - Karl Fischer: Volumetry/Coulomtery - Stromboli (sample changer) Methods for water determination Givaudan Samples, Givaudan Why water determination? Method Results (LabX) Conclusion 4

6 Types of water A Karl Fischer Titration is only possible if water is freely available Solids contain water as : Water Example: Food Entrapped water Crystal water Surface water Capillary bound water Example: Salt Ca 2 SO 4 * 2 H 2 O (gypsum) Water Example: Sugar, pharmaceuticals Water Example: Biological samples 5

7 Types of sample preparation Ways of releasing water : Dissolve the sample in a solvent Crush the sample Extract water with a solvent Evaporate water by heating 6

8 Volumetric / Coulometric Titration Volumetric Karl Fischer Iodine is added by a burette during titration. Water as a major component: 100 ppm % - + Coulometric Karl Fischer Iodine is electrochemically generated during titration. Water in trace amounts: 1 ppm - 5 % 7

9 Repeatability 100 % 10 % 1 % 1000 ppm 100 ppm 10 ppm 1 ppm Coulometry Not suitable for coulometry srel < 0.5 % srel % srel > 5 % Volumetry srel < 0.5 % srel % srel > 5 % Not suitable for volumetry 8

10 Coulometric Karl Fischer Titration Principle Generator electrode Sensor electrode Cathode Anode + double platinum pin electrode Catholyte Ceramic diaphragm Anolyte 9

11 Coulometric Karl Fischer Titration With or without diaphragm + I - - I Iodine is only present in the anode compartment and reacts with water. I - - I - I I - + It is possible that iodine molecules diffuse to the cathode and convert to iodide ions. 10

12 Stromboli Oven with automatic sample changer for Karl Fischer Titration Temperature range from C Automated titration of up to 14 solid or liquid samples Easy sample handling Unique sample processing Automatic control with V30 / C30 / T70 / T90 Automated drift and blank determination Useful optional accessories 11

13 Easy sample handling Unique sample processing To titration cell Gas & water dry carrier gas oven Sample vial The vial is introduced into the oven by a lift. The aluminum foil is penetrated by the glass capillary. Sample Heating from the bottom Moisture is transferred with dry carrier gas via the outlet into the titration cell. 12

14 Mettler Toledo Theory Agenda Types of water Which samples - Karl Fischer: Volumetry/Coulomtery - Stromboli (sample changer) Methods for water determination Givaudan Samples, Givaudan Why water determination? Method Results (LabX) Conclusion 13

15 Methods for Water Determination Drying oven Dry sample in a drying oven at higher temperature until the weight is constant. Advantages: Large number of samples. Large sample size possible. Disadvantages: Long measurement time (some hours) Large amount of manual effort. Other volatile substances vaporize. 14

16 Methods for Water Determination Drying oven Dry sample by IR or halogen heater on a balance until the weight is constant. HB43 Halogen Moisture Analyzer Advantages: Simple operation. Short measurement time (5 15 minutes) Disadvantages: Single sample at a time. Other volatile substances vaporize. Decomposition of the sample. 15

17 Methods for Water Determination Karl Fischer Titration Fast ( minutes) Selective for water Accurate and precise Wide measuring range (ppm %) 16

18 Solvent Manager Compact KF titrators External device for KF liquid handling Includes strong air pump (diaphragm pump) and electromagnetic valve Fully controlled by the titrator On top of waste bottle Drain and fill titration cell without getting in contact with solvents! 17

19 Mettler Toledo Theory Agenda Types of water Which samples - Karl Fischer: Volumetry/Coulomtery - Stromboli (sample changer) Methods for water determination Givaudan Samples, Givaudan Why water determination? Method Results (LabX) Conclusion 18

20 Givaudan Head office in Venier, Switzerland 82 Locations worldwide 2 Locations in the Netherlands, Naarden and Barneveld Since 2007 global leader in flavours and fine fragrances 19

21 Samples Givaudan Flavours Savoury Fine fragrances Fine fragrance Beverages Consumer products Sweet goods Ingredients Dairy 20

22 Why measuring water? Micro biological effect Customers want to buy a product and not water! 21

23 Mettler Toledo Theory Agenda Types of water Which samples - Karl Fischer: Volumetry/Coulomtery - Stromboli (sample changer) Methods for water determination Givaudan Samples, Givaudan Why water determination? Method Results (LabX) Conclusion 22

24 Method Givaudan Reagens: Hydranal Coulomat AD Electrode: Generator electrode and platinum pin electrode Blanc Sample: 0,1 0,2 gram Concentration sample: 100ppm-8% Oven temperature 120 o C Calculation 23

25 Method Givaudan Easy operation Pretitration Weighing sample in vial Place sample vial in Stromboli Next sample Result (after +/- 5 min) Wait for result One click 24

26 Mettler Toledo Theory Agenda Types of water Which samples - Karl Fischer: Volumetry/Coulomtery - Stromboli (sample changer) Methods for water determination Givaudan Samples, Givaudan Why water determination? Method Results (LabX) Conclusion 25

27 Results Blanc Stromboli E t curve Drift t curve 26

28 Results Sample E t curve Drift t curve 27

29 Stromboli: Sample determination Cacao sample Average (%) Karl Fischer Volumetrisch (% water) Karl Fischer Stromboli (% water) S

30 Sample Determination: Examples Stromboli: Sample determination Sample KF Vol mean srel n Stromboli mean srel Lemon 4,7% 0,2% 6 6,2% 0,1% 5 Cacao 2,1% 0,3% 5 3,3% 0,1% 5 Lime 1,9% 0,1% 5 4,2% 0% 5 Aardbei 2,1% 0,1% 5 3,2% 0,1% 5 n Analyse time of KF volumetry is minutes. It takes some time (minutes) before beaker is waterfree (standby or low drift). Analyse time with Stromboli is 6-10 minutes. And immediately ready for next sample. 29

31 Mettler Toledo Theory Agenda Types of water Which samples - Karl Fischer: Volumetry/Coulomtery - Stromboli (sample changer) Methods for water determination Givaudan Samples, Givaudan Why water determination? Method Results (LabX) Conclusion 30

32 Conclusion Water determination in food samples using karl Fischer titrator and Stromboli Selective method for water analysis Less sample preparation Fast result Automatisation is possible Suitable for production area Data processing by ethernet connection 31

33 Thank you for you attention 32