Blank Optimization Using Ultrapure Water Suitable for Trace Ion Analysis.

Transcription

1 Blank Optimization Using Ultrapure Suitable for Trace Ion Analysis. Daniel Darbouret and Ichiro Kano Millipore Corporation Laboratory Division Research and Development BP St Quentin-en-Yvelines Cedex - France IICS - 11th -14th September Nice France

2 Table of Contents Preliminary studies (raw material selection). Materials and methods. Performance of the initial water purification system combining reverse osmosis and electrodeionization. Ionic behavior at each step as well as resulting typical ion chromatograms. Ion chromatography ultratrace analysis on ultrapure water.

3 Preliminary Studies- Material Extractables 15 C oncentration,µg/l HDPE1 HDPE2 HDPE3 PP Material chloride nitrite nitra te sulfa te

4 Preliminary Studies- Material Extractables 1000 C oncentration, µg/l fluoride chloride nitrite nitra te sulfa te FEP PFA1 PFA2 PFA3 PFA4 PTFE PE PA PU Material

5 Materials and Methods

6 Purification Chain Initial purification system Polishing system Reverse osmosis Electrodeionization Storage reservoir polishing unit Municipal RO reject RO permeate EDI concentrate EDI product Ultrapure

7 Anion Analysis Instrument : Sample volume : Column : Dionex DX GP50 Pump Autosampler AS40 - CD 20 Conductivity meter - Peaknet software. 25 µl ( ppb) 200 µl ( ppb) AS12A/AG12A Eluent : 2.7 mm Na 2 CO 3 / 0.3 mm NaHCO 3 Flow rate : 1.5 ml/min. Suppressor : ASRS Ultra ma recycle mode.

8 Cation Analysis Instrument : Sample volume : Column : Eluent : Flow rate : Suppressor : Dionex DX GP50 Pump Autosampler AS40 - CD 20 Conductivity meter - Peaknet software. 25 µl ( ppb) 200 µl ( ppb) CS12A/CG12A Methanesulfonic acid 20mM. 1.0 ml/min. CSRS Ultra - 50 ma recycle mode.

9 Instrument : Sample volume : Trace Anion Analysis IC-7000 (Yokogawa Analytical Systems). 0.5 ml (direct injection) or 10 ml (via concentration column) Separation column : ICS-A44/A44G Precolumn : J9199AR Concentration column :ICS-ANC Eluent : 4.0mM Na 2 CO 3 /4.0mM NaHCO 3 Flow rate : 1.0 ml/min. Temperature : 40 ºC

10 Results

11 Initial Purification System Initial purification system Polishing system Reverse osmosis Electrodeionization Storage reservoir polishing unit Municipal RO reject RO permeate EDI product EDI concentrate Ultrapure

12 Initial Purification System Initial purification system Polishing system Reverse osmosis Electrodeionization Storage reservoir polishing unit Municipal RO reject RO permeate EDI product EDI concentrate Ultrapure

13 Reverse Osmosis Performance Ion concentrations in ppb (µg/l) Tap water RO permeate %reject Conductivity (µs/cm) Li Na K Mg Ca F Cl NO SO

14 Reverse Osmosis Performance Cation Study ppb or µs/cm ( ) conductivity Li Na K Mg Ca running time (minutes)

15 Reverse Osmosis Performance Cation Study 5100 ppb Na K Mg Ca running time (minutes)

16 Reverse Osmosis Performance Anion Study ppb or µs/cm (- - - ) conductivity Fluoride Chloride Nitrate Sulfate running time (minutes)

17 Electrodeionization Process Initial purification system Polishing system Reverse osmosis Electrodeionization Storage reservoir polishing unit Municipal RO reject RO permeate EDI product EDI concentrate Ultrapure

18 EDI Principle A C A C Cathode Anode H + Cl - Na + Cl - OH - Na + _ + Cl - Na + H + Cl - Na + Cl - Na + OH - waste product A - Anion selective Membrane C - Cation selective Membrane

19 EDI Performance RO permeate EDI conc. EDI dilute Conductivity (µs/cm) < 1 Li < 1 Na < 1 K < 1 Mg < 1 Ca < 1 F 7 17 < 1 Cl < 1 NO < 1 SO < 1 Ion concentrations in ppb (µg/l)

20 Typical Ion Chromatograms 3 : Tap water ; 2 : RO water ; 1 : RO/EDI water Cations

21 Typical Ion Chromatograms 3 : Tap water ; 2 : RO water ; 1 : RO/EDI water Anions

22 Final Polishing Unit (Milli-Q Element) Polishing unit Reverse osmosis Electrodeionization Storage reservoir polishing unit Municipal RO reject EDI product EDI concentrate RO permeate Ultrapure

23 Ultrapure : Optimized Flow Schematic Elix type Feed UV lamp resistivity cell Automatic footswitch valve pump Purification media PVDF point of use filter UHMWPE point of use filter

24 Impact of Extractables, Final Filter Conventional PVDF membrane filter C oncentration,µg/l chloride nitra te sulfa te volum e,l UHMWPE optimized membrane filter Concentration,µg/L chloride nitrate sulfa te volum e,l

25 Final Polishing Unit Results Trace Anion Analysis chloride 100 ng/l phosphate 500 ng/l nitrate 100 ng/l sulfate 100 ng/l nitrite 100 ng/l bromide 100 ng/l Standards Ultrapure water

26 Final Polishing Unit Results Trace Anion Analysis Ultrapure water Chloride < 10 Nitrite < 10 Phosphate < 50 Bromide < 10 Nitrate < 10 Sulfate < 10 concentration in ng/l (ppt)

27 Final Polishing Unit Results (ICP-MS) Trace Elemental Analysis DL QL 7 Li B Na Mg Al <DL(0.033) 39 K Ca Cr <DL(0.096) 55 Mn Fe Co <DL(0.42) 58 Ni <DL(0.063) 63 Cu <QL(0.13) 64 Zn <DL(1.4) 88 Sr <DL(0.004) 107 Ag Cd <DL(0.67) 138 Ba <DL(0.13) 208 Pb <DL(0.1) All values in ng/l (ppt)

28 Conclusions In order to minimize the risk of ion contamination, it is recommended to select appropriate raw material, perform extractable studies and choose optimized purification technologies. A combination of reverse osmosis and electrodeionization technologies ensures high and consistent quality of purified water. A final polishing unit consisting of UV photooxidation, high grade purification media and optimized final filter, produces high quality ultrapure water. As a result, combination of all these features can provide ultrapure water suitable for ppt ion chromatography analysis.