SMASH Poster Abstract Review

Polymeric NMR Sample Tubes Evaluated in a 1 mm Microprobe

Michael J. Cavaluzzi1, David J. Kiemle2, Deborah J. Kerwood3, and Philip N. Borer1,3
1. Advanced Resonance Technologies, Inc., 111 College Pl, 2-212 CST, Syracuse, NY 13244-4100 2. Chemistry Department, SUNY College of Environmental Science & Forestry, 121 Jahn Lab, 1 Forestry Dr, Syracuse, NY 13210-2726 3. Chemistry Department, Syracuse University, Syracuse, NY 13244

Polymeric NMR Tubes have advantages over glass in most applications: • Polymeric tubes are shatterproof • Ultra-thin walls afford sensitivity increases of 20-40% • Polymer tubes are easy to fill and to recover sample • Standard probeheads and sample changers can be used. Here we describe the performance of polymer tubes compared to glass capillaries, both having 1 mm outside diameter. The mass sensitivity of 1 mm probes about four times that of 5 mm probes, yet the former have not found wide acceptance due to the difficulty of using glass capillaries. Samples were tested on a Brüker DRX-600 with a 1 mm TXI room temperature probehead. Primary comparisons are between polymeric tubes with inside diameters of 0.826 (ART-1A), 0.851 (ART-1B), and 0.889 mm (ART-1C), and a glass capillary with ID estimated at 0.814 mm. The resolution for 1% CHCl3 in d6-acetone was comparable at half-height (1 Hz) while the lineshape for polymer tubes was typically 20% broader at the base. The signal-to-noise ratio in the polymer tubes scales almost exactly with volume increase in the active region of the receiver coil (tested with 0.1%, 1% and 10% ethylbenzene in CDCl3). 30-40% less time will be required to achieve the same S/N in the larger ID polymer tubes compared to glass capillaries. Spectra acquired in ART-1C tubes will be shown, including: (1) a 1D 1H-spectrum of 1 microgram of stigmasterol where the chemical shifts are easily resolved in 512 scans, (2) a 2D 1H-15N-HSQC of 70 micrograms of 15Nu-ubiquitin shows that a 21 min acquisition distinguishes the expected peaks and has an increase in S/N ~ 30% over a glass capillary, and (3) a 2D 1H-15N-HSQC of 15Nu-labeled NCp7 protein from HIV-1. The mass of the protein is about 2% of that often used in a 5 mm room temperature probe (1 mM, 500 microliters). MJC and PNB hereby disclose their financial interest in ARTech, represented at the SMASH conference by Norell, Inc. NMR tubes with other dimensions will be available soon. Supported in part by NIH grant RR18442 to MJC and PNB.