Matrix suppression effect

McCombie, G. Knochenmuss, R. Small-molecule MALDl using the matrix suppression effect to reduce or eliminate matrix background interferences. Anal. Chem. 2004, 76, 4990-4997. 

Knochenmuss, R., Dubois, F., Dale, M.J. and Zenobi, R. (1996) The matrix suppression effect and ionization mechanisms in matrix-assisted laser desorption/ionization. Rapid Conunun. Mass Spectram. 10, 871-877. 

Figure 1 shows a standard curve for aqueous molybdate standards (circles). The line through the points that are indicated by triangles is a standard additions experiment on a serum sample containing about 5 /xg/L Mo. The serum matrix interference reduces the sensitivity markedly. The difference in slopes between the aqueous standards and the sample illustrates the matrix suppression effect. Figures 2 and 3 show... 

The same scheme has been adopted for the determination of several antibacterials (quinolones and erythromycin A), fungicides, and parasiticides in salmon tissue. In this case, samples were extracted with acidic ACN, and then dSPE was carried out with a Bondesil NH2 sorbent, followed by LC-TOE-MS determination. Excellent recoveries were obtained with the exception of enrofloxacin (40%), although matrix suppression effects were observed for most of target compounds. ... 

Despite the successful application of MALDl and DIOS in the analysis of LMM compounds, the analysis remains a challenge. This stems primarily from low ionization efficiencies due to a lack of functional groups with high proton affinity, matrix suppression effects, isobaric overlay of the matrix with the analyte, and the high volatility of many analytes. One approach to improve the analysis of LMM compounds is by derivatization. The derivatization of samples prior to MS analysis has been widely employed in gas chromatography-mass spectrometry (GC-MS)... 

Sample preparation can be tailored to suppress excess matrix background peaks by controlling the matrix analyte ratio. Although numerous groups observed this phenomenon soon after the introduction of MALDl, it has only recently been exploited to achieve its fuU potential for smaU-molecule analysis. The matrix analyte molar ratio within the matrix crystals has been found to be critical for MALDl quantification [10]. Critical parameters for a successful execution of the matrix suppression effect (MSE) include sufficient analyte and optimized laser intensity. 

Becanse of the differences in the matrix components of samples such as urine, blood, or serum, simple external calibration can often produce erroneous results. For that reason, it is common to use other calibration methods such as standard additions or addition calibration to achieve accurate data. These methods have been described in detail in Chapter 13, but they are required because of the matrix suppression effects caused by large variations in patients biological fluid samples. The sample preparation method used will often dictate the type of calibration curve to use, but all three... 

The various matrix ions, which seem at first glance to be independent classes, may interconvert by ion-molecule reactions. In fact, this seems to be necessary for the widely observed matrix suppression effect discussed below. While not extensively investigated, for DHB it has been shown that interconversion of m mH, and mNa... 

Knochenmuss, R. Dubois, E Dale, M. J. Zenobi, R. The Matrix Suppression Effect and Ionization Mechanisms in Matrix-Assisted Laser Desorption/ lonizatioiL Rapid Commun. Mass Spectrom. 1996,10, 871 77. 

To eliminate isobaric interferences derived from the sample matrix and matrix suppression effects, specific sample preparation approaches, such as evaporation followed by dissolution of... 

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