Remote NMR Data Acquisition and Processing in the Organic

A procedure for enabling remote and hands-on access to a Varian Mercury 300 MHz Nuclear Magnetic Resonance (NMR) spectrometer in a large organic chemi...
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Remote NMR Data Acquisition and Processing in the Organic Chemistry Curriculum

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Caleb Benefiel, Ron Newton, and Gregory J. Crouch* Department of Chemistry, Washington State University, Pullman, WA 99164-4630; *[email protected] Karen Grant Columbia Basin College, 2600 N. 20th Avenue, Pasco, WA 99301-3379

This paper describes a procedure that allows approximately 200 students in a large organic chemistry laboratory course hands-on access to a 300 MHz Varian Mercury nuclear magnetic resonance spectrometer (NMR). Additionally, this paper describes a procedure for providing remote access to this NMR spectrometer by a community college and two Washington state high schools. For either procedure, chemistry students are able to perform any NMR experiment supported by Varian’s VNMR software. The following brief overview is designed to allow the reader to determine if such a procedure would be appropriate at their institution. Detailed installation and configuration instructions (including software screen captures) are provided in the Supplemental MaterialW and on the remote NMR project Web site at http:// www.pnla.wsu.edu/NMR/aboutNMR.htm (accessed Sep 2003).

NMR experiment (e.g., 1H, 13C, DEPT). For 2-D experiments (e.g., COSY, NOESY, HETCOR), NMR data acquisition is queued to run when longer periods of instrument time are available (in the evening). As with 1-D NMR data processing, 2-D data processing (which usually requires a great deal of student time) is done remotely. In a typical semester, organic chemistry students gather between five and ten NMR data sets, depending on the laboratory assignments. Although teaching assistants are always stationed at the NMR, students typically require little direct assistance after two or three NMR training sessions. A detailed instruction sheet covering 1-D NMR data acquisition and processing procedures is provided to each student (see Supplemental Material,W section XVI). These instructions allow most students to work autonomously.

On-Campus NMR Access

Off-Campus NMR Access

Washington State University (WSU) is a land grant institution with an undergraduate enrollment of approximately 18,000 students on the main campus. WSU’s full semester organic chemistry course typically enrolls between 180 and 220 students per year. It is essential that chemistry students in this course have access to the types of instrumentation they will likely encounter in a research environment; however, providing instrument access to such large numbers of students is challenging. For less expensive instrumentation (e.g., gas chromatographs, infrared spectrometers, etc.), multiple instruments permit large classes access with minimal wait time. However, for expensive single instruments, such as an NMR spectrometer, student access can be problematic. To address this issue, NMR experiments are divided into two parts—a quick data acquisition portion and a somewhat longer remote data processing portion. For data acquisition, 10-minute blocks of instrument time are scheduled both during and outside of the normal lab period. Scheduling software (such as the Faces Scheduling System1) is used to coordinate these time blocks. Students arrive 10 minutes before their scheduled time block to prepare their NMR sample. During the scheduled time block, a teaching assistant instructs students in using the NMR. Each student is taught how to lock and shim the instrument, and how to acquire and save their raw data. Using an associated computer laboratory, students are then taught how to remotely process their data using X-Windows terminal emulation software.2 Rather than using a generic spectral data processing system, X-Windows software was chosen for remote processing since it allows students to use Varian’s industry-standard VNMR software.3 This procedure supports acquiring and processing any routine 1-D

After we had successfully integrated NMR into WSU’s undergraduate curriculum, a local community college and two area high schools expressed interest in gaining remote NMR access for their students. Columbia Basin College, a local community college with an annual enrollment of approximately 7,400 students, has approximately 50 organic chemistry students per year. Ferris High School and Mead High School in Spokane, Washington each have approximately 30 and 75 students, respectively, studying organic chemistry each year. At all three institutions, access to NMR was desired in order to better prepare students in organic chemistry. To provide access for these schools, a small grant was obtained from Battelle to help purchase Windows-type computers and printers for each remote location. An information technologist from WSU traveled to each remote site to install and configure the computer system. Additionally, teachers at each school traveled to WSU to train both on NMR use and methods to integrate NMR into their organic curriculum. Once the computers were configured, standard Internet access protocols were used to remotely connect to the NMR at WSU. In order for instructors and students to remotely access the NMR, samples are mailed to WSU in sealed numbered vials. A teaching assistant prepares these samples by dissolving them in the required deuterated solvent and then transferring the resulting solutions to NMR tubes. Based on a provided schedule (e.g., sample 1 at 10:30 a.m.; sample 2 at 11:00 a.m., etc.), the teaching assistant loads each sample into the NMR, followed by a quick lock and shim. For routine 1-D NMR experiments, students are allocated 45 minute blocks of time to remotely shim, acquire, and process their

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Journal of Chemical Education • Vol. 80 No. 12 December 2003 • JChemEd.chem.wisc.edu

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data. For any required 2-D experiments, additional access time is scheduled as required. Figure 1 details a computer and instrumentation connection flowchart for on-campus remote NMR data processing and off-campus NMR data acquisition and processing outlined above.

on-campus NMR lab

off-campus remote NMR site

NMR workstation

off-campus connections

Necessary Hardware and Software This section lists the necessary hardware and software required in order to replicate our procedure at other institutions.

Windows Terminal The remote acquisition and processing computer terminal configuration was based on a Microsoft Windows system with at least 256 MB RAM. Peripherals included a 17-inch monitor (or larger) that supports a resolution of 1024 ⫻ 768 pixels at a 75 Hz refresh rate, a 32 MB video card, a 24⫻ CD-ROM drive, a 1.44 MB floppy drive, 30 GB hard drive, a 100BaseT network card, and a Hewlett Packard LaserJet printer (5L or 1100). Additionally, an Internet connection capable of at least 128 kbps upstream/downstream speed was required. Terminal Software Windows XP Professional was used as the operating system and Hummingbird Exceed Version 7 was used as the Xwindows emulator.2 In addition, an Internet connection is required along with networking parameters (IP address, subnet mask, etc.). NMR Hardware The NMR configuration included a Varian Mercury 300 MHz NMR3 and Sun Microsystems 300 MHz Ultra 10 workstation with 128 MB RAM, a 4 GB hard drive, a 19inch, high-resolution Ultra 5 monitor, and a PCI Ethernet adapter board.4 Secondary Solaris Server A secondary Solaris server running VNMR is required to allow students to simultaneously process NMR data sets. Each server accommodates 12 students. At WSU, three such servers are used to enable 36 students simultaneous access to the VNMR in order to process their data. Older, inexpensive (ca. $500) servers such as Sun Microsystems 270 MHz Ultra 5 workstations are ideal. Minimum server configurations include: 128 MB RAM, a 4 GB hard drive, a 19-inch, high-resolution Ultra 5 monitor, and a PCI Ethernet adapter board.4 NMR Software VNMR software version 6.1c3 was installed on both the NMR workstation and all secondary Solaris servers. NMR and Terminal Software Installation and Configuration A brief overview of NMR workstation configuration and remote terminal software installation and configuration is

on-campus Solaris server room secondary Solaris serve n

secondary Solaris server 1

Windows terminal with printer

12 Windows terminals

12 Windows terminals

on-campus computer lab Network Connection Printer Connection Internet Figure 1. Hardware connection flowchart for on-campus data processing and off-campus data acquisition and processing.

presented here. Minimal experience with Solaris and VNMR is sufficient to implement this installation and configuration. Detailed installation and configuration instructions are provided in the Supplemental MaterialW and on the remote NMR project Web site at http://www.pnla.wsu.edu/NMR/ aboutNMR.htm (accessed Sep 2003). Two usage scenarios are discussed below: off-campus remote NMR data acquisition and processing (scenario 1) and on-campus remote NMR data processing (scenario 2).

Scenario 1: Remote Data Acquisition and Processing Only a single VNMR session is supported in this scenario. This scenario is appropriate for users requiring a single Windows-type remote terminal. A ‘secondary Solaris 7 server’ is not required since there is never more than one user logged into the NMR workstation at any one time. For this scenario, an NMR scheduler should be used so that a local user will not log on while a remote user is acquiring data and crash the VNMR acquisition process. Scenario 2: Remote Access as a Concurrent Session This scenario is required if users will be remotely processing their data on a Windows-type computer terminal while other users are acquiring data at the NMR workstation. Multiple concurrent VNMR sessions are supported in this scenario.

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Conclusion

Acknowledgments

For the past two years, chemistry students at WSU, Columbia Basin College, Mead High School, and Ferris High School have been using the procedures outlined in this paper with great success. Given the continuity of Varian’s VNMR software, any Varian NMR with an Internet connection could be adapted for either remote data processing or remote data acquisition and processing. Providing remote access to schools who cannot afford to purchase or maintain a NMR will extend the ability of chemistry students to obtain hands-on access to this critically important research tool. The detailed installation and configuration instructions provided in the Supplemental MaterialW and on the remote NMR Web site are sufficient to allow someone with minimal experience in Solaris and VNMR to configure their NMR for remote use.

Partial support for this work was provided by the National Science Foundation’s Division of Undergraduate Education (through grant DUE 9850771), Washington State University, and Battelle.

Supplemental Material Detailed installation and configuration instructions (including software screen captures and a detailed instruction sheet for students covering 1-D NMR data acquisition and processing procedures) are provided in this issue of JCE Online. W

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Notes 1. Faces Scheduling System is a free service developed by William York and Saeed Roushanzamir at the Complex Carbohydrate Research Center at the University of Georgia and is available at http://www.ccrc.uga.edu/faces.html (accessed Sep 2003). 2. Hummingbird Exceed, Hummingbird Limited, 1 Sparks Avenue, Toronto, Ontario, M2H 2W1, Canada. http:// www.hummingbird.com/products/nc/exceed/index.html (accessed Sep 2003). 3. Varian NMR and VNMR, Varian, Inc., Corporate Headquarters, NMR Systems, 3120 Hansen Way, Palo Alto, CA 943041030. http://www.varianinc.com/cgi-bin/nav?varinc/docs/products/nmr/ (accessed Sep 2003). 4. Sun Microsystems, Inc., and Solaris, 4150 Network Circle, Santa Clara, CA 95054. http://www.sunmicrosystems.com (accessed Sep 2003).

Journal of Chemical Education • Vol. 80 No. 12 December 2003 • JChemEd.chem.wisc.edu