Qualitative and quantitative determination of poloxamer surfactants by mass spectrometry.
Poloxamers are polyethylene-polypropylene glycol linear co-polymers. A simple matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) method has been developed for the determination of the average molecular weight of poloxamers. The molecular mass of five standard poloxamers determined by MALDI closely corresponds to that specified by the manufacturers, and no mass distribution effects were observed. Quantitation of distributions based on the molecular mass envelope using electrospray (ES) ionization was unsuccessful. To overcome this problem, quantitation was based on fragment ions (m/z 45 and 59) which gave reproducible signals using a very high orifice voltage ( approximately 200 eV). Poloxamer concentrations were determined accurately with a good linear response using the standard addition method. We believe that the use of very small fragment ions for quantitation of polymers may become a widely applicable general technique.
Takáts
Z
Z
Institute of Chemistry, Chemical Research Center of the Hungarian Academy of Sciences, H-1025 Budapest, Pusztaszeri út 59-67, Hungary. ztakacs@cric.chemres.hu
Vékey
K
K
Hegedüs
L
L
D002138:Calibration; D008970:Molecular Weight; D009883:Ophthalmic Solutions / Q000032:analysis; D020442:Poloxamer / Q000032:analysis* / Q000737:chemistry; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D013501:Surface-Active Agents / Q000032:analysis* / Q000737:chemistry
D009883:Ophthalmic Solutions; D013501:Surface-Active Agents; D020442:Poloxamer