Jn. Alexander et Cj. Quinn, ORGANIC-ACID ANALYSIS BY ION CHROMATOGRAPHY PARTICLE-BEAM MASS-SPECTROMETRY, Journal of chromatography, 647(1), 1993, pp. 95-100
Ion chromatography-mass spectrometry (IC-MS) has been investigated, us
ing the particle beam interface, as an analytical technique for the an
alysis of weak organic acids. Ion-exclusion chromatography is a techni
que for separating weak acids. Using dilute HCI as the mobile phase, w
eak acids are separated on a cation-exchange resin. IC-MS was used to
detect and identify weak acids in commercial grape juices and red wine
. Analyses were performed using both electron (EI) and chemical ioniza
tion (CI). Isobutane CI readily produced protonated molecular ions, an
d combined with structural information obtained from EI analyses, iden
tification of weak acids was possible. A main advantage of this techni
que is that co-eluting acids can be identified, whereas with conductiv
ity and UV detection this is difficult. To simplify these analyses, so
lid-phase extraction was used to remove sugars from the juice and wine
samples.