Albuterol (or albuterol sulfate) is used for the treatment of asthma.  It's generally taken as either tablets or from an inhaler.  WCAS provides testing for albuterol according to USP monographs as well as in inhalers.

There are at least two methods for determining the dose of Albuterol from an inhaler, an HPLC method based upon the USP monograph for the API or LC-MS.  USP sets standards for albuterol tablets but not inhalers.  The method for assaying tablets is based on reverse phase HPLC with an ion pair reagent with detection using UV absorbance at 276 nm.  For legal cases, we prefer the following method using LC-MS because it provides definitive identification of the albuterol active ingredient as well as the dose assay.

Albuterol by LC-MS
(update 12-2006)

We have developed a method for confirmation of Albuterol in Inhalation Solutions. This method uses LC-MS with electrospray ionization. With a relatively high capillary voltage, some fragmentation is induced to give a representative spectrum. The chromatographic conditions use a mixed mode LC column.  This gives good peak shape for the albuterol and 

A representative LC-MS chromatogram and mass spectrum are shown below.

For a quotation...

Albuterol by GCMS

First, the samples are prepared by removing the canisters from the mouthpiece and dispensing five actuations from each sample into water containing salicyl alcohol as an internal standard. An aliquot of the water is then evaporated to dryness and the TMS derivatizing agent is added to the residue. The solutions are then analyzed by GCMS. Quantitation is performed using the internal standard method against a five-point initial calibration. Additionally, one sample is prepared in duplicate. Results are given as free albuterol and albuterol sulfate per actuation from the valve.

Example Report:

Formerly West Coast Analytical Service (WCAS) and Bodycote Testing Group