By Bojidarka Ivanova * , Michael Spiteller

1. UV–MALDI mass spectrometric quantitation of pesticides of uracil substance group in fruit based direct huddled soft drinks – evaluation of the matrix effects By Bojidarka Ivanova*, Michael Spiteller Lehrstuhl für Analytische Chemie, Institut für Umweltforschung, Fakultät für Chemie und Chemische Biologie, Universität Dortmund, Otto-Hahn-Straße 6, 44227 Dortmund, Nordrhein-Westfalen, Deutschland • Analytical contributions for elaborations and developments of selective and precise protocols for determination of contaminations in foods are of primary interest and goal on the frontier of modern analytical chemistry. They impact significantly the quality control and monitoring programs, ensuring an accurate assessment of the risk for human health. An expected, but very important introduction for the “analytical chemistry of foods” • Due to high complexity and diversity of foodstuffs matrixes as well as variety of chemical, physical and physicochemical properties of contaminating analytes, the choice of instrumental method is of crucial importance.

2. Uracil–substance group pesticides as analytes of primary interest • Neurotoxic and potential carcinogenic agents • A large usage in agricultural practice for treatment of citrus fruit. Challenge in the analysis of fruit based direct huddled soft drinks with pulp • Complex foodstuffs matrix–effect, which difficult the estimation of sampling bias. • Lack of exact standard (or certified) reference materials, representative to variety of heterogeneous foodstuff drink matrixes. Instrumental methods for analysis of soft drinks The analytical practice mainly employs the LC–MS/MS, HPLC–ESI (or APCI)–MS/MS and/or UPLC–ESI (or APCI)–MS/MS for accurate quantitation of the agricultural contaminations in waters, soils, and/or foodstuffs matrixes, involving a routine quantitative methodology. Then, where is the novelty of the study and which method/instrumental characteristics of UV–MALDI–Orbitrap–MS contributed to improvement of the method performance parameters and the reliability of the analytical information?

3. Advantages of UV–MALDI–Orbitrap–MS towards the routinely implemented hybrid methods • Ultra-high accuracy and precision, enable analysis of individual analytes in complex multicomponent mixtures • Method detection limits up to attomol concentrations • Fast measurement and operation time • Flexibility of the sample preparation techniques for measurements • Sample – pretreatment limited stages, which reduce significantly the systematic and random errors • Instrumental flexibility • Direct assay and imaging of homogeneous or heterogeneous liquid, • semi–liquid and solid–state samples. Outlook • Methodological instrumental developments for improvement of: • Quantitation procedure • Portable instrumental design, which allows effective time and scene control of market food products

4. MS – spectrum of uracil-type pesticides; Fragmentation scheme [2Glu+H]+, [2Fru+H]+, and [2Suc+K]+ II MS – spectrum of soft drink

5. Method performance parameters UV–MALDI–Orbitrap–MS method Concentration LODs of 0.011 ng.g-1 Achieved through: Under direct assay of the dropped and evaporated drinks from the bottle* containing drink and pulpon the MALDI – sample holder and laser ablation at lex = 337.2 nm Y1I0(1-5,DHA)-2 Relative abundance (RA) of the MS intensity of the analyte peak versus the concentration (C) HPLC–ESI–MS/MS Concentration LODs  0.017–0.043 ng.g-1 Achieved through: Routinely implemented sample pre-treatment procedures, for heterogeneous fruit based direct huddled soft drinks with pulp* *Since the market drinks are pesticide free, the analysis involved an additional step of contamination with variety of pesticides and their mixture, same for both methods.