Mass Spectrometry Requisition Details
Test Guidelines are as follows:
- Samples should be submitted in a 2mL HPLC vial
- Samples should be prepared to a concentration range 1-50µg/mL
- Samples should be prepared in a water-soluble organic solvent or solvent/water mix and filtered via 0.2u syringe filter. An acid or base to 0.1% v/v may also be added (see below)
- Compounds containing ionisable functional groups (i.e. amines or carboxylic acids) will generally ionize much easier than neutral compounds
- Ionisation can be enhanced by promoting protonation or deprotonation of the analyte. For example, addition of 0.1% Acetic acid to an analyte containing an amino functional group will protonate the amine, hence (M+H +) will be detected in positive ion mode. Addition of 0.1% NH 4 OH to an analyte containing an acidic functional group will deprotonate the acid, hence (M-H +) will be detected in negative ion mode.
- Only volatile buffers should be used if needed to prepare analyte, i.e. ammonia, acetic or formic acid. Avoid the use of non-volatile buffers i.e. phosphates, borate
- The use of Trifluoroacetic acid should be avoided
- Completed requisition forms should be handed to a technician along with the samples and also submitted via email to orbitrap@tcd.ie. The office is situated in Room 3.1 on the 3rd Floor of the School of Pharmacy & Pharmaceutical Sciences
- Results will be returned by email