Utilizing Ne SSI for Analytical Applications Dave Veltkamp

Utilizing Ne. SSI™ for Analytical Applications Dave Veltkamp* Brian Marquardt* Charlie Branham† *Center for Process Analytical Chemistry (CPAC) University of Washington, Seattle WA † Grad Student from Bart Kahr’s group in Chemistry, UW

CPAC Project Overview Goal is to support Ne. SSI related development within CPAC n n Developing platforms and demo applications Support PI and student use in research programs Promote and support wider Ne. SSI adoption and use n n n Web based support Interaction with Ne. SSI community Legal umbrella for cooperative development

Old Ne. SSI Gas/Vapor System 1 MFC Controls N 2 dilution flow -Ne. SSI substrate with 3 MFC’s -2 bubblers for vapor generation Single inlet line (N 2) 2 MFCs Control N 2 flow to bubblers Outlet line to flow cell Standard Ace Glass impingers

Optical Flow Cell Flow cell is a simple cross fitting n n 6 -around-1 fiber optic for source and collection Delrin rod with sensing compound coated on end Multiple crosses can be chained together for screening several compounds at once Optical detection using simple reflectance optical measurement n n n Ocean Optics USB 2000 VIS spectrometer (350 -1000 nm) 405 nm blue LED excitation Compound fluorescence signal in region 600 -900 nm

Vapochromatic Response Full spectrum response of the 0%, 10%, and 50% bubbler flow samples used to make the PLS model showing both the change in intensity and shift in peak maximum with changing benzene concentration.

Vapochromic #1 Response * MFC #3 run at 5% FF rather than 50% FF

Vapochromic #3 Response

Bubbler Results (Benzene Conc. ) Benzene concentration (ppm) calculated from the weight loss experiment data as a function of bubbler flow rate (%FF N 2)

New Gas Sensor Testing System More capability to generate analytical vapors, gas blending, and on-line dilution of vapor streams for method development work This system delivered by CORCOR Tech to UM last week and will facilitate collaboration with Kent Mann

The New CIRCOR Ne. SSI System Has Arrived in Minnesota

Reconfiguration of CPAC Ne. SSI™ System Our Swagelok Ne. SSI™ system proven to be very easy to change to suit needs n n Replaced bubblers with permeation tubes and oven Changed to look at CO 2 in N 2 blending Changed to look at O 2 and moisture in air Investigation of flow, mixing, and dead volumes Used to evaluated new analytical instruments in CPAC lab n n ASI micro. Fast GC – 2 column GC with trap injection Aspectrics EP-IR mid infrared spectrometer with gas cell Lab. VIEW software developed to automate experiments

Reconfigured Ne. SSI™ System

Schematic of System Needed to design system with multiple (3) dilution stages n Somewhat complex flow paths to minimize dead volumes Had to compromise automated vs. manual control of N 2 flows in first two stages n Lack of additional MFCs required manual metering valves

System Flows By closing valves and using the MFCs as flow meters, all flows can be measured Closing off the N 2 flows (SV 2 and MFC 2) and waste valves (PV 3 and PV 4) allows flow thru bubbler to be measured n MFC 3 and MFC 1 set to “valve open” setpoint All flow streams and legs of system can be flushed by N 2

System Flows (cont. )

Dilution Flows 1 st dilution of bubbler flow at input to MFC 3 n n Most of flow goes to waste, MFC setpoint typically 1 -5% N 2 flow regulated by waste needle valve 2 nd dilution at outlet port of MFC 3 n n Again most of flow going to waste, MFC 1 set to 1 -5% N 2 and 2 nd diluted sample flows set by needle valves PV 2 and PV 4 3 rd dilution at output port of MFC 1 n N 2 flow controlled by MFC 2 Important to balance pressures and flows to avoid unexpected flow conditions – some tweaking required!!

Aspectrics EP-IR Instrument 128 channels from 2. 50 to 5. 00 microns (4000 -2000 cm-1) n n Each channel approx 19. 7 nm wide “band pass” Also a 256 channel model available Runs at an acquisition frequency of 100 scans (rotation) per second n n Real-time data collection of fast events High averaging for low LOD applications Small size and rugged construction n Only moving part is the encoder disk Suitable for high vibration process environments No hygroscopic parts Several optical configuration of sampling cell/accessories possible Powerful on-line embedded chemometrics software

Aspectrics EP-IR Technology

Aspectrics EP-IR with Gas Cell 15” 7” Spectrometer 5. 2” Gas cell Glow source

ASI micro. FAST GC™ System on loan from ASI as part of WTC project with Infometrix Programmed temperature gas chromatograph using n n n Syringe or valve inlets to a flash evaporator. Sample delivery to an adsorbent trap for concentration Desorbtion and delivery to twin capillary columns Temperature programmed column elution Detection by simultaneous flame ionization detectors (FID). Trace levels down to low parts per billion can be measured. Compact and easy to setup chromatography n n n Weight on the order of 12 pounds Size on the order of a shoe box Speed of analysis on the order of 10 times faster than competitors Very easy to use n n Trap injection makes it simple to use and automate Really more like a spectrometer or sensor in operation Even non-chromatographers can use it!!

ASI micro. FAST GC™ dual columns and heater assembly column Fan compartment sheath end of heated head of columns finger tight columns connections zone Injector Heater FID Manifold splitter septa Back Panel flow restrictor Heated FID Air Sample Inlet carrier FID Vents flow removable glass liner V 4(n open) Injection Trap & V 8 V 1 fuel purge fan V 2 FID external Heater cooling V 5 hydrogen V 3 @ 40 psi P P P Ballast electronic pressure regulators Pneumatic Manifold Injector vent Restrictor vent Vacumn Pump vacuum pump vent

micro. FAST GC™ Column Details 3 meter column length Columns oven sheath ~1 mm ID column #1 100 micron ID DB-5 column #2 100 micron ID DB-1701 column heater sheath Column temperature sensor Column heater

micro. FAST GC™ Analytical Cycle Typically 2 -3 minutes Sample Time Trap pre-purge time Column cool-down time Injection time Trap cool-down time Trap preheat time Trap cleanout time Column separation time Equilibrate time Adjustable parameters that affect analysis – lots of tuning potential

Interfacing to ASI micro. Fast GC™

Example Benzene Chromatograms Not very demanding chromatography – but convenient reference method

Experiment: Blending CO 2 with N 2 Goal was to characterize the Ne. SSI™ system, software control, and the EP-IR gas cell data collection n Series of step changes in MFC setpoints for CO 2 dilution Different hold times (delay) between setpoint changes Series repeated 5½ times Bubbler replaced with CO 2 from tank Results show very good reproducibility and control of the gas blending system n n Dynamic response consistent with expectations No dead volume issues

CO 2 Blending Experimental Design Note: MFC #2 offset by 90%FF, numbers on plot represent step hold time

EP-IR Spectra from CO 2 Experiment

1 st PC of EP-IR Spectra PCA Model

Step times and Spectral Response CO 2 setpoints inverted & offset for clarity Note: Total flow = 250 sccm, volume of cell ~ 210 ml – so about 1 -2 min exchange time (lag) seems about right

CO 2 Exp. Cycle Reproducibility

2 nd PC of EP-IR Spectra PCA Model

PCA results showing nonlinear behavior at high CO 2 conc.

On-line Chemometric Model Results

Used a stainless steel condenser as “oven” for permeation tubes n n Removed condenser core and replaced with permeation tubes Mounted in single-port ½” adapter to direct N 2 up thru oven Second ¼” adapter block returns flow into Ne. SSI™ Temperature maintained by flowing water thru jacket from heater/chiller Permeation tubes made inhouse n n Teflon tubing sealed at both ends Made different tubes for water, benzene, and toluene vapors dilution flow Ne. SSI™ Permeation Tubes

Permeation Tube Results Water permeation tube study n n Vapochrome compound (Kafty) Oven temp. set at 50°C MFC flow rate set at 10%, 20%, 30%, 40%, and 50% for 30 min Spectra taken at each flow rate Benzene permeation tube n n Vapochrome compound (#4) Oven temp. set at 30°C MFC flow rate set at 0%, 10%, 20%, 30%, 40%, and 50% for 30 min Spectra taken at each flow rate

Conclusions and Future Work Setup of Ne. SSI™ Vapor Platform complete (for now) n n n Lab. VIEW software developed and tested Flow dynamics tested and characterized New vapor generation ideas to be tested New instrumentation interfaced and tested n n Both Aspectrics EP-IR and ASI micro. FAST GC™ valuable additional tools for monitoring gas mixing and delivery Additional applications from Sponsors welcome Vapochromic compound testing continuing n n Moisture, CO 2, O 2 and BTEX sensors testing underway Additional screening and analytical performance testing planned Plan to get back to some microreactor work n n Parker Ne. SSI™ system for reactant and product streams Microreactor components from Microglass & IMM on hand Fuel cell studies with Eric Stuve and Chem. E. students planned WTC Project with Infometrix on Process GC interfaced to Ne. SSI™