FAQ


MSF Frequently Asked Questions

General Submission Requirements

How do I submit a sample?

To submit a sample to the chemistry MSF, fill out a submission form.  Fill out the form by providing as much information as you can.  Attach your sample to the submission form and leave the sample with the submission form in the inbox in room 41 Chemistry.  If you are sending samples from outside the university please contact us regarding proper procedures.

Where can I submit my sample?

If you are on campus, samples can be dropped off in room 41 Chemistry. If you are submitting a sample outside Texas A&M University, please contact us and use the express shipping address provided to send your samples.

How can I get an account with MSF?

If you are located on campus, you can use your department account number. However, if you are sending a sample from outside Texas A&M University and it is your first time, we need you to fill out the customer information form to create an account with us. Return the completed form to us by contact us or fax. Once you open an account with us, you can generate a PO number to subsequently use the facility. For details please contact us.

Can I submit a sample from outside Texas A&M University?

We accept samples from other universities, government or private institutions.  However, we give priority to samples submitted from within TAMU research community. See fee structure for samples submitted from other institutions.

If you are submitting samples for the first time, please fill out customer information form and return it to us by contact us or fax. Once you open an account with us, you can use a PO number to subsequently use the facility.  For details please contact us.

Where is the Chemistry MSF located?

Chemistry MSF is located in room 41 Chemistry.

Sample Submission Guidelines

Sample preparation plays a critical role in obtaining good-quality MS data.  Quality of spectrum decreases as impurities, contaminants or matrices in your sample increase.  Presence of salts and detergents, improper solvent choice, and not knowing the right concentration are some examples of factors that adversely affect results. Your MS spectrum is largely dependent on how your sample is prepared.  We have summarized some of the things that you should consider before you submit your sample for MS analysis.

In what form should I submit my sample?

Samples can be submitted in solid, liquid, and or in solution form.

How much sample do I need to submit?

The amount of sample needed depends on the mass spectrometry technique used.  In general 1 mg/ml of sample in solution or 1 mg in solid form is enough for all applications.  If you have a limited quantity of sample, please contact the MSF service staff.

What solvent can I use?

Solvents such as water, methanol, acetonitrile, chloroform, tetrahydrofuran, and dichloromethane are generally accepted for MS analysis.  If you are submitting a sample in solution, on the submission form you should indicate the solvent that your sample is dissolved in and the solvent in which your sample is soluble.

Samples can also be submitted in buffers for electrospray (ESI) or MALDI analysis if they are in one of the following MS compatible buffers: ammonium acetate, ammonium formate, ammonium hydrogencarbonate at concentration 10 mM or less. Acid additives: acetic, formic acid trifluoracetic (TFA) acids are acceptable.

Will you accept samples submitted in highly viscous solvents like dimethylsulfoxide (DMSO) and dimethylformamide (DMF)?

Avoid using salts, phosphate, HEPES, citrate or sulfate buffers, detergents (Tween, Triton, NP-40, SDS), urea, glycerol, carbohydrates, EDTA, GnHCl, plastics and plasticizers, polyethylene glycols (PEG) and other polymers that interfere with the ionization of your analyte.

If you have salts or detergents in your sample, please contact the MSF staff.  Some samples can be cleaned up using a Zip Tip (C4 or C18) to remove salts and buffers.  There is an additional charge for zip tipping.  Note that not all samples can be cleaned with ZipTip.

What are the specifics for each ionization technique?

GC-MS

Sample concentration
1 mg of sample is enough for pure solid, liquid, or oil samples. Solutions be submitted not exceeding 1 mg/mL in a suitable solvent for GC-MS.

Solvents
GC-MS requires volatile organic solvents such as dicholormethane, hexane, methanol, ethyl ether etc. GC-MS can’t be performed directly on samples dissolved in water.
Avoid
Some class of compounds are not amenable for GC-MS and should not be submitted for GC-MS analysis, if the sample contains a strong acid or base, salt, water, metal, or polymeric material. Avoid using plastic or polymeric vials or parafilm.

ESI: Direct Infusion

Sample concentration and amount
For direct infusion ESI, at least 0.1 mg of sample may be needed for pure solid, liquid, or oil samples.  Solutions should be 50 to 100 micromolar in a suitable solvent for ESI.  We need at least 100 microliters of solution at a concentration of 50 to 100 micromolar in a suitable ESI solvent to run the sample.
Solvent
Suitable solvents for ESI include methanol, acetonitrile, and mixtures of water and acteonirtile or methanol. Samples are accepted in pure water, tetrahydrofuran and dichloromethane, but cannot be run directly from these solvents.

MALDI:

Sample concentration and amount
For MALDI, amount of sample will depend on mass.  For masses between 500 and 2000, 0.1 mg may be sufficient for pure solid, liquid, or oil samples.  For higher masses, higher amounts of sample may be needed, depending on the mass, purity, and type of sample.  Solutions should be at least 100 µM concentration, and we need at least 5 microliters of solution in most cases.  
Solvent
Suitable solvents include water, methanol, dichloromethane, acetonitrile, and others.

What do I do with samples that need special storage or treatment?

Light sensitive
Samples that are sensitive to light can be placed in a vial covered by aluminum foil.
Low temperature storage
If a sample needs to be kept at low temperatures (refrigeration or freezing), please find a MSF staff member or, place it in one of the trays on the refrigerator or freezer and write down your sample ID on the sample vial and write down the location of your sample tray number (1, 2, or 3) and row (A, B, C, etc.) on the sample submission form.
Air sensitive
Samples that are air sensitive or decompose quickly need special attention.  Please contact us in advance to make arrangements before submitting the sample.
Acid/base sensitive
Some samples can degrade if an acid or base is added to the sample.  If you are submitting a sample that is sensitive to acid or base, please indicate so.

Do I need to provide a Chemical Structure?

Please provide us with a chemical structure and formula of your analyte.  The structure helps us to determine the ionization method and interpret data.

What is unit mass or accurate mass? Which one should I request?

Unit Mass
In unit mass or nominal, the mass is generally accurate to within few tenth of a Da.  Mass spectrometers that are labeled as low resolution normally provide unit mass.  All our EI, CI and APCI ionization techniques are low resolution and provide only unit mass.  We provide unit mass for all samples submitted unless exact mass is requested.
Accurate Mass
In exact or accurate mass measurement, mass is accurately determined to four decimal places using a high resolution mass spectrometer that is calibrated internally or externally.  Typically, mass accuracy below 5 ppm is provided.  In order to request for this service, unit mass should be determined first.  Accurate mass is only provided for samples submitted for ESI analysis.

Data

When should I expect MS data?

Typically we provide data within 24 hours of sample submission. ESI samples are run frequently throughout the day and results may be available within the same day. Unless otherwise noticed, we run MALDI samples every day at 3:30 PM. and results may be available after 5:00 PM of the same day.

Where can I pick my analysis result?

You can pick your analysis result from room 41 Chemistry. We normally print results and attach to the sample submission form, unless an electronic copy is requested.

Can I get an electronic copy?

We provide a text file of the MS data for all researchers upon request. We can only provide power point presentation of the MS analysis results for researchers who are located outside chemistry building if requested. We don't provide power point presentation for researchers located in chemistry building.

How long can my data be stored with the MSF lab?

Data will be stored within MSF for only two years. It is your responsibility to obtain a copy of your data within the time frame.

Publication

What are the rules or policy for publication or presentation of data obtained from MSF?

Research carried out in part or in full using Chemistry MSF services and/or contributions requires acknowledgements of facility, facility and staff, or co-authorship and acknowledgment of facility. Details are given in the acknowledgment policy.

What should we include in our experimental or results section?

If you are writing a manuscript and you are going to include data obtained from MSF, please contact us and we will provide details.

Should we send our publication once it is accepted?

If you publish a paper that includes data obtained by MSF, it is mandatory that you send us citation of the publication or a PDF file once your work is published on the web.