Utilizing NeSSI™ 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 NeSSI related development within CPAC Developing platforms and demo applications Developing platforms and demo applications Support PI and student use in research programs Support PI and student use in research programs Promote and support wider NeSSI adoption and use Web based support Web based support Interaction with NeSSI community Interaction with NeSSI community Legal umbrella for cooperative development Legal umbrella for cooperative development

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

Optical Flow Cell Flow cell is a simple cross fitting 6-around-1 fiber optic for source and collection 6-around-1 fiber optic for source and collection Delrin rod with sensing compound coated on end 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 Ocean Optics USB2000 VIS spectrometer ( nm) Ocean Optics USB2000 VIS spectrometer ( nm) 405 nm blue LED excitation 405 nm blue LED excitation Compound fluorescence signal in region nm Compound fluorescence signal in region 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 N2)

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 NeSSI System Has Arrived in Minnesota

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

Reconfigured NeSSI™ System

Schematic of System Needed to design system with multiple (3) dilution stages Somewhat complex flow paths to minimize dead volumes Had to compromise automated vs. manual control of N 2 flows in first two stages 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 (SV2 and MFC2) and waste valves (PV3 and PV4) allows flow thru bubbler to be measured MFC3 and MFC1 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 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 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 PV2 and PV4 3 rd dilution at output port of MFC 1 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 ( cm -1 ) Each channel approx 19.7 nm wide “band pass” Each channel approx 19.7 nm wide “band pass” Also a 256 channel model available Also a 256 channel model available Runs at an acquisition frequency of 100 scans (rotation) per second Real-time data collection of fast events High averaging for low LOD applications Small size and rugged construction 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 Glow source Gas cell Spectrometer 15” 7” 5.2”

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

ASI microFAST GC™

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

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

Interfacing to ASI microFast GC™

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

Experiment: Blending CO 2 with N 2 Goal was to characterize the NeSSI™ system, software control, and the EP-IR gas cell data collection Series of step changes in MFC setpoints for CO 2 dilution Series of step changes in MFC setpoints for CO 2 dilution Different hold times (delay) between setpoint changes Different hold times (delay) between setpoint changes Series repeated 5½ times Series repeated 5½ times Bubbler replaced with CO 2 from tank Results show very good reproducibility and control of the gas blending system Dynamic response consistent with expectations Dynamic response consistent with expectations No dead volume issues 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 Note: Total flow = 250 sccm, volume of cell ~ 210 ml – so about 1-2 min exchange time (lag) seems about right CO 2 setpoints inverted & offset for clarity

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

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

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

Conclusions and Future Work Setup of NeSSI™ Vapor Platform complete (for now) LabVIEW software developed and tested LabVIEW software developed and tested Flow dynamics tested and characterized Flow dynamics tested and characterized New vapor generation ideas to be tested New vapor generation ideas to be tested New instrumentation interfaced and tested Both Aspectrics EP-IR and ASI microFAST GC™ valuable additional tools for monitoring gas mixing and delivery Both Aspectrics EP-IR and ASI microFAST GC™ valuable additional tools for monitoring gas mixing and delivery Additional applications from Sponsors welcome Additional applications from Sponsors welcome Vapochromic compound testing continuing Moisture, CO 2, O 2 and BTEX sensors testing underway Moisture, CO 2, O 2 and BTEX sensors testing underway Additional screening and analytical performance testing planned Additional screening and analytical performance testing planned Plan to get back to some microreactor work Parker NeSSI™ system for reactant and product streams Parker NeSSI™ system for reactant and product streams Microreactor components from Microglass & IMM on hand 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 NeSSI™