University of California, Riverside

High Resolution Mass Spectrometry Facility



Capabilities and Limitations


Equipment Available for routine use

1. Waters GCT (2008) high resolution mass spectrometer, with EI/CI and LIFDI capabilities. This instrument can be operated remotely, allowing users to control data acquisition and data processing from their own location. It has been used in this manner for teaching purposes in addition to normal analyses. Contact us for more information about this.

If you publish data acquired on this instrument, please acknowledge NSF grant CHE-0742001

2. SCIEX 5800 TOFTOF System WinXP Data System

3. ThermoScientific TSQ - triple quadrupole LCMS instrument with Windows XP OS

If you publish data acquired on this instrument , please acknowledge a grant from the National Center for Research Resources S10RR022331

4. Agilent LCTOF (2006) A high resolution TOF analyzer with Windows XP based OS and APCI/ESI ionization. This instrument is available for hands on student access four hours each day as a means to obtain MS data quickly and inexpensively. Anyone wishing to use the instrument in this open access mode should contact facility personnel to learn more about the capabilities and limitations.

If you publish data acquired on this instrument, please acknowledge NSF grant CHE-0541848

Services Available

A. APCI/ESI (Multimode)

Available in both positive and negative ion modes on the Agilent LCTOF only .

Restrictions
  1. Upper mass limit about 3000 for "small" molecules.
  2. Both flow injection and LC modes of operation are available
  3. All samples must be soluble. (Avoid  DMSO if possible.  The presence of DMSO in a sample requires LCMS sample introduction and increases the cost of analysis.
  4. Accurate mass measurements are provided routinely to about 1200.  This can also be done for molecules up to 2500  if needed.
  5. Sample requirements are 1- 10 micrograms

B. EI and CI

Performed on the  Waters GCT GC/MS for mixtures or pure samples in either positive or negative ion mode. Gases used are methane, isobutane and ammonia. Accurate mass measurements for these ionization modes can also be performed

Sample introduction on the GCT is via GC injection. We use a standard 30 meter, 0.25 micron DB-5 column for all analyses. If you need a different column, contact us to schedule this work. The user would need to provide the special column.

Note: Although the usable mass range of the GCT is about 4000 dalton, in practice we restrict its use to about mass 900 for EI analyses.

C. Isotopic incorporation analyses

This allows the user to determine the percent incorporation of heavy isotopes of elements in a molecule. In order to acheive good accuracy, we require the nonlabelled analog of each material be submitted at the same time as the labelled material.

D. MALDI - Matrix Assisted Laser Desorption Ionization

Useful for MW determination via both nominal and accurate mass measurements. MS/MS capability is not possible on our equipment at this time. 

No ability to perform on-line separations, samples should be fairly pure.

Sample amount required is compound dependent, for peptides with MW less than 5kd, provide 200 pmoles, 1 nmole required for MW greater than 5kd. For oligonucleotides: 750 pmole - 1 nmole samples size is required.

Please ensure salts have been removed from sample, we recommend ion exchange chromatography ( salt free mobile phases) for oligonucleotides.

E. TSQ Triple Quadrupole LC/MS Instrument

  • Small molecule and peptide structural analysis (fragmentation, LC/MS, LC/MS/MS analysis).

F. Liquid Introduction Field Desorption Ionization (LIFDI)

ESI and MALDI are primarily used for polar molecule analysis. LIFDI can be used for non-polar molecules. It can be used for very volatile molecules as well in conjunction with GC sample introduction. Large molecules that don't ionize well by ESI or MALDI can be examined by LIFDI with direct sampling from a solvent. The current mass limit for LIFDI is about 3000 dalton.

As of summer 2012, we can also offer the ability to provide accurate mass data to four decimal places in LIFDI. This allows determination/confirmation of molecular formula. UCR is one of the few facilities that offers this analysis.

For more details click here. 

 

 

How to request service

1. Contact us via one of the following: call 951-827-5287  or send e-mail to jie.zhou@ucr.edu. Facility personnel will guide you through the process.

2. Samples are analyzed on a first come, first served basis. Requests for rush service should be made only for those samples which are unstable. Such requests can only be made by the research professor or his designee. The designee must be known to facility personnel prior to the request. The request can be made either verbally or in writing.

3. Turnaround times vary depending on our backlog. When you call, facility personnel can provide an update.

4. Submit samples using the sample submission guide. Failure to follow the guide will result in analysis delays.

More Information

General Campus Information

University of California, Riverside
900 University Ave.
Riverside, CA 92521
Tel: (951) 827-1012

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Facility Information

High Resolution Mass Spectrometry Facility
Chemical Sciences Bldg.

Tel: (951) 827-5287
Fax: (951) 827-4713
E-mail: Jie.Zhou@ucr.edu

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