FAQs

What can I do to ensure fast turn-around times?

The most common causes of delays are mistakes on the submission form. This includes incorrect mass, lack of a formula or structure, a formula and mass that don't agree, illegible hand writing, and incorrect e-mail addresses.

We will correct trivial mistakes (although this can still cause delay), but major mistakes will require you to correct the form, or submit a new form. You will be notified by e-mail if this is the case.

Only use the current sample submission form for internal or external samples.

Only use the current year's sample labels (those beginning with MSFxx, where xx is the last two digits of the current year).

If a week has passed since your submission and you have not received an e-mail, please let us know. (Note that staff-run LC/MS samples may take longer.) There may have been an issue with communication. For example, your data may have been sent to the wrong e-mail address.

What can mass spectrometry tell me about the purity of my sample?

It is important to understand that mass spectrometry cannot tell you if your sample is pure. It can however tell you if your sample is impure. Your mass spectrum may look clean, but we cannot rule out the possibility of impurities that may not ionize in the mode or method that was selected.

Where can I process my data and find my old data?

Data acquired using the Walk-Up LC/MS can be found on the first workstation in WEL 4.218, the workstation in NHB 5.502, or the workstation in NHB 5.342.

Data acquired by the MSF staff (ESI, LC/MS) can be found on the second workstation in WEL 4.218 (Bond).

Data acquired using the Walk-Up GC/MS can be found on the third workstation in WEL 4.218 (Neo).

How long does the mass spec facility store my data?

Original data will be stored on the acquisition instrument computer for a period of at least six months.

All data is regularly backed up to the department server.

• • • • Data run by the MSF staff will be retained on the server for one year.

      • Data acquired using the Walk-up LC/MS or GC/MS instruments will be retained on the server for 90 days.

PDFs should be available for several years, but this is not a guarantee.

If there is any possibility that you will need your data beyond one year (or 90 days for Walk-Up data) it is your responsibility to save a copy of the original data!

What was the LC method used for my sample?

Each LC sample data file has an associated method report. Use this guide to generate an LC method report for your sample in MassHunter.

Should I request Accurate Mass Report or Full Scan on the submission form?

If you request "Accurate Mass Report" you will only receive data that covers a very narrow mass range. This is optimal for confirming the accurate mass of a compound and is necessary for publication, but will give you no information whatsoever about how pure the compound may or may not be.

If you want a scan that covers a wide mass range, please request "Full Scan". This is optimal to check for impurities or starting materials and to confirm, in general, that your target is present.

If you want both a wide mass range scan (to check for impurities or starting materials) and accurate mass measurement of one or more peaks, then request "Both".

Accurate Mass Report Vs. Full Scan Example

Should I request ESI or CI?

If you are unsure, the easiest thing to do is to select "whatever works" in the drop down box on the submission form and let us figure it out.

ESI (electrospray ionization) works best when the target contains a basic nitrogen atom or multiple oxygen atoms in close proximity. These links provide a brief and detailed explanation of electrospray ionization.

CI (chemical ionization) will work well for most thermally stable compounds that have a mass below 500. (Sometimes up to mass 1000.) These links provide a brief and detailedexplanation of chemical ionization.

Based on your structure we will also determine if APCI or APPI may work better. We currently do not have a MALDI instrument, but there is one available in the Pharmacy department.

More information on resolution in EI/CI mass spectrometry and a visual example can be found here.

What solvents can I use for sample submission?

Most solvents are acceptable, however methanol (MeOH), acetonitrile (ACN), and dichloromethane (DCM) are preferable for our facility. Solvents that are undesirable are dimethyl sulfoxide (DMSO) and dimethylformamide (DMF). The submission of solid and/or neat samples is always an acceptable choice. In that case, it is very important to specify which solvent(s) we should use to dissolve your compound.