Occurrence, partition and removal of pharmaceuticals in sewage water and sludge during wastewater treatment.

Honey: Chemical composition, stability and authenticity.

Comparison of QuEChERS sample preparation methods for the analysis of pesticide residues in fruits and vegetables.

Matrix-dependent signal suppression or enhancement represents a major drawback in quantitative analysis with liquid chromatography coupled to atmospheric pressure ionization mass spectrometry (LC-API-MS). Because matrix effects (ME) might exert a detrimental impact on important method parameters (limit of detection, limit of quantification, linearity, accuracy, and precision), they have to be tested and evaluated during validation procedure. This review gives a detailed description on when these phenomena might be expected, and how they can be evaluated. The major sources of ME are discussed and illustrated with examples from bioanalytical, pharmaceutical, environmental, and food analysis. Because there is no universal solution for ME, the main strategies to overcome these phenomena are described in detail. Special emphasis is devoted to the sample-preparation procedures as well as to the recent improvements on chromatographic and mass spectrometric conditions. An overview of the main calibration techniques to compensate for ME is also presented. All these solutions can be used alone or in combination to retrieve the performance of the LC-MS for a particular matrix-analyte combination.

An overview of matrix effects in liquid chromatography-mass spectrometry.

Fluoroquinolone antibiotics: an emerging class of environmental micropollutants

Matrix effects in pesticide multi-residue analysis by liquid chromatography-mass spectrometry.

Tutorial review on validation of liquid chromatography-mass spectrometry methods: part II.

Ionization efficiency (IE) of different compounds in electrospray ionization (ESI) source differs widely, leading to widely differing sensitivities of ESI-MS to different analytes. An approach for quantifying ESI efficiencies (as logIE values) and setting up a self-consistent quantitative experimental ESI efficiency scale of organic compounds under predefined ionization conditions (ionization by monoprotonation) has been developed recently. Using this approach a logIE scale containing 62 compounds of different chemical nature and ranging for 6 orders of magnitude has been established. The scale is based on over 400 relative IE (ΔlogIE) measurements between more than 250 different pairs of compounds. To evaluate which molecular parameters contribute the most to the IE of a compound linear regression analysis logIE values and different molecular parameters were carried out. The two most influential parameters in predicting the IE in ESI source are the pKa and the molecular volume of the compound. This scale...

Electrospray Ionization Efficiency Scale of Organic Compounds

A review of analytical techniques for determination of Sudan I-IV dyes in food matrixes.

Simultaneous determination of fluoroquinolones, sulfonamides and tetracyclines in sewage sludge by pressurized liquid extraction and liquid chromatography electrospray ionization-mass spectrometry.

Koit Herodes

Papers

Matrix effects in pesticide multi-residue analysis by liquid chromatography-mass spectrometry.

Tutorial review on validation of liquid chromatography-mass spectrometry methods: part II.

Electrospray Ionization Efficiency Scale of Organic Compounds

A review of analytical techniques for determination of Sudan I-IV dyes in food matrixes.

Simultaneous determination of fluoroquinolones, sulfonamides and tetracyclines in sewage sludge by pressurized liquid extraction and liquid chromatography electrospray ionization-mass spectrometry.