MUR. Market Specialist

Transcription

1 Cyanide Methods and the 2010 MUR William Lipps Market Specialist

2 Fundamentals of Cyanide Chemistry

3 Free Cyanide is the CN ion and HCN, generate HCN at ph Na C N

4 Metal Complexes that require acid to generate HCN Available CN

5 Strong Metal Complexes are stable in acid solution require UV or distillation

6

7 MUR Table 1b Examples

8 Cyanide methods measure the various cyanide species Strong Metal Complexes Fe, Co, Pt, Au Total CN Available CN Weak to Moderately Strong Metal Complexes Ag, Cd, Cu, Hg, Ni, Zn Free CN HCN CN -

9 Cyanide Preparation Techniques

10 Conway Micro-diffusion Cell Absorber Solution Sample Solution

11 Manual distillation Macro Distillation MIDI Distillations

12 Automated Distillation Distillation and condenser Distillate

13 Gas diffusion CN - Na + OH - Na + H 2 O Membrane HCN H + Cl -

14 Ion Chromatography Eluent Detector Pump Column Sample

15 Determinative ti Step

16 Titration by silver ion

17 Ion Selective Electrode (ISE) S-2

18 Colorimetric methods Turbidity

19 Electrochemistry CN - Ag(CN) 2 -

20 Free Cyanide Analysis

21 Free Cyanide Methods Method Number Description Measurement ASTM D4282 Passive Diffusion Colorimetry ASTM D7237 Flow Injection Gas Diffusion - Amperometry

22 ASTM D Buffer

23 Comparison of Results for Free Cyanide

24 Available Cyanide Analysis

25 Amenable Cyanide CATC methods measure available cyanide Method Number Description Measurement SM 4500-CN G Alkaline Chlorination/ Manual Distillation Colorimetry ASTM D 2036 Alkaline Chlorination/ Manual distillation Colorimetry, Gas Diffusion - Amperometry

26 WAD Cyanide methods measure available cyanide Method Number SM 4500-CN I ASTM D 2036 Description Buffered ph 4.5 manual Distillation Measurement Colorimetry Buffered ph 4.5 Colorimetry, manual distillation Gas Diffusion - Amperometry

27 Ligand Exchange methods measure available cyanide Method Number OIA 1677 ASTM D 6888 Description Measurement Ligand Exchange / Flow Gas Diffusion - Injection Amperometry Analysis Ligand Exchange / Flow Injection Analysis Gas Diffusion - Amperometry GD t th d d t i GD-amperometry methods do not require distillation

28 Ligand Exchange GD-amperometry methods get better recovery WAD CATC OIA 1677

29 Ligand Exchange GD-amperometry methods are more precise OIA 1677

30 OIA 1677 or ASTM D6888 flow diagram Acid Reagent

31 Ligand Exchange GD-amperometry methods have fewer interferences CATC WAD OIA 1677 N-organics Excessive Iron Cyanide None Concentration SCN,NHNH 3,NO 2 Dependent S 2 O 3,H 2 O 2 Concentration Dependent

32 Ligand Exchange GD-amperometry methods give you results in minutes CATC WAD OIA 1677 Sample Preparation Analysis 2 distillations 2 3 hours 1 2 minutes 1 distillation No 2 3 hours distillation 1 2 minutes 1 2 minutes Total Time 3 4 hours 3 4 hours 1 2 minutes

33 Total Cyanide Analysis Manual al Distillation Methods

34 Total cyanide methods using manual distillation Descriptive Name Method Number Description Measurement EPA Midi Distillation MgCl 2 Automated t Colorimetry Total Cyanide ASTM D2036 Midi / Micro/macro Distillation MgCl 2 Colorimetry/ISE/ amperometry/ic ASTM D 7284 Midi / Micro Distillation MgCl 2 Gas Diffusion - Amperometry

35 Most total cyanide analyses are by EPA or similar Prolonged heating strong acid (ph <2) Purging into base Colorimetry

36 Semi-automated colorimetric cyanide analysis flow diagram

37 The OIA1677 configuration is used to determine CN by ASTM D7284 Acid Reagent

38 GD-Amperometry results are equivalent to colorimetry on interference free samples

39 Automated total cyanide methods use UV to liberate HCN from Fe Descriptive Name Method Number Description Measurement Total Cyanide ASTM D4374 (Kelada 01) ASTM D7511 High power UV- Auto distillation Alkaline ph Low power UVpH <2 Automated colorimetry Gas Diffusion - Amperometry [Fe(CN) 6 ] -3 + H + 6 HCN + Fe +3 hv ( ) 6

40 A sample diagram of the Kelada 01 automated cyanide method

41 A sample diagram of ASTM D7511 To waste AMP detector Gas diffusion module Sample Base reagent UV digestor To waste Carrier Air TA 1 TA 2

42 Comparison of Kelada and ASTM D7511 Kelada 01 ASTM D7511 Pump Tubes 15 5 Reagents Pyridine No Pyridine Distillation Yes No SCN Interaction % %

43 Comparison of Total CN methods ASTM D7284 ASTM D7511 Sample Preparation 2 3 hour distillation 1 3 hour distillation No distillation Analysis 1 2 minutes 1 2 minutes 1 2 minutes Total Time 3 4 hours 2 4 hours 1 2 minutes

44 Playing against the odds EPA 335.4

45 ASTM D7511 obtains equivalent recovery to EPA EPA D ppm Fe (III) 0.2 ppm Fe (II)

46 ASTM D7511 evaluated 15 metal-cyanide complexes for recovery EPA ASTM D7511

47 ASTM D7511 evaluated 9 matrices by interlaboratory trial EPA ASTM D7511

48 ASTM D7511 evaluated interferences with and without CN present ASTM D7511 EPA

49 ASTM D7511 evaluated lower concentrations during inter-lab study ppb EPA ASTM D7511

50 ASTM D7511 obtains lower results on the ASTM challenge matrix pp pb EPA ASTM D7511

51 ASTM D has fewer interferences than distillation b pp D Sulfite Thiosulfate Thiocyanate Sulfide 20 ppm interferent

52 ASTM D7511 analyzes samples without distillation, shortening time to results Distillation Analysis

53 A summary of free Cyanide Methods Diffusion/Colorimetry ASTM D4282 Free CN GD-Amperometry ASTM D7237 WAD CN CATC Available CN Distillation/ Colorimetry Chlorination Distillation/ Colorimetry ASTM D2036 or SM4500 ASTM D2036 or SM4500 LE GD-Amperometry OIA 1677 or ASTM D6888

54 Manual distillation total cyanide methods Method Number Description Measurement SM 4500-CN C Manual Macro Distillation Mg Cl 2 Manual colorimetry / ISE ASTM D 2036 Manual Manual colorimetry, Macro/Midi/Micro ISE, GD- Distillation MgCl 2 amperometry, IC EPA Midi Distillation MgCl 2 Automated Colorimetry ASTM D 7284 Gas Diffusion - Midi / Micro Distillation Amperometry MgCl 2

55 Automated total cyanide methods Descriptive Name Method Number Description Measurement Total Cyanide ASTM D4374 (Kelada 01) ASTM D7511 High power UV- Auto distillation Alkaline ph Low power UVpH <2 Automated colorimetry Gas Diffusion - Amperometry

56 GD-amperometry methods provide the best benefits No distillation Or pyridine barbituric acid Low MDL (0.5 ppb) Fewer Interferences High Throughput Ease of Operation

57 Thank You Questions? For more information contact