IC–MS Determination of Ionic Compounds in Toothpaste
March 1st 2004A fast and easy-to-use method for the identifcation and determination of active anionic ingredients in toothpaste is presented using ion chromatography in combination with electrospray mass spectrometry. In this application, positive identification of glycerol, sorbitol, chloride, fluoride, sulphate, monofluorophosphate and polyphospates, in addition to citrate and saccharin, is achieved in one chromatographic run with a total analysis time of 22 min.
Source Design and the Utility of Multimode Ionization
January 1st 2004In the first of this new column, Michael Balogh takes a look at source design and the strengths of multimode ionization, such as its ability to switch at high speeds between electrospray and atmospheric-pressure chemical ionization.
This article establishes the estimation of the uncertainty associated with the chromatographic determination of biogenic amines. The authors identify and estimate each source of uncertainty to establish the accuracy of results and to obtain a better understanding of the method. Thus, measurement uncertainty was split into two sections: uncertainty related to the working conditions, which considers the equipment used, and inherent uncertainty, which includes the chemical stages indicated in the procedure as well as calibration sources, taking into account the existence of the matrix effect. Recovery studies also were made to quantify the contribution of bias to the overall uncertainty. This parameter was calculated for the determination of biogenic amines in different types of samples.