Determination of okadaic acid and its derivatives in mussels and decontamination

An approach involving both chemical and biological methods was undertaken for the detection and quantification of the marine toxins okadaic acid (OA), dinophysistoxin-1 (DTX-1) and their respective esters in mussels from different sampling sites in Greece during the period 2006–2007. Samples were analyzed by means of a) high performance liquid chromatography with fluorometric detection (HPLC-FLD), using 9-athryldiazomethane (ADAM), as a pre-column derivatization reagent, b) liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) and c) the mouse bioassay. Free OA and DTX-1 were determined by both HPLC-FLD and LC-MS/MS, while their respective esters were determined only by LC-MS/MS after alkaline hydrolysis of the samples. The detection limit (L.O.D.) and quantification limit (L.O.Q.) of the HPLC-FLD method were 0.015 μg/g HP and 0.050 μg/g HP, respectively, for OA. The detection limit (L.O.D.) and quantification limit (L.O.Q.) of the LC-MS/MS method were 0.045 μg/g HP and 0.135 μg/g HP, respectively, for OA. Comparison of results between the two analytical methods showed excellent agreement (100%), while both HPLC-FLD and LC-MS/MS methods showed an agreement of 97.1% compared to the mouse bioassay. In the present study, both ozonation (15 mg kg-1 for 6 h) and -irradiation (6 kGy) have been utilized in order to reduce toxin content of contaminated shucked mussels, collected during the DSP episodes of 2007 and 2009 in Greece. DSP toxicity was detected using the mouse bioassay (MBA) while determination of toxin content of the okadaic acid (OA) group (both free and esterified forms) was conducted by LC/MS/MS analysis. Toxin reduction using -irradiation was in the range of 12-36%, 8-53% and 10-41% for free OA, OA esters and total OA respectively. Appearance and texture of irradiated mussels deteriorated, pointing to a low potential for commercial use of this method. Ozonation of mussels resulted in toxin reduction in the range of 6-100%, 25-83% and 21-66% for free OA, OA esters and total OA, respectively. Reduction of OA content was substantially higher in homogenized mussel tissue, compared to that of whole shucked mussels. In addition, differences detected with regard to quality parameters (TBA, sensory attributes) between ozonated and control mussels were not considerable. Present results indicate that upon optimization, ozonation may have the potential for post-harvest commercial DSP detoxification purposes in shucked mussels.Στη παρούσα μελέτη πραγματοποιήθηκε α) ο προσδιορισμός των τοξινών της ομάδας του οκαδαϊκού οξέος (ΟΑ) σε μύδια από τον Ελλαδικό χώρο, τα οποία επιλέχθηκαν με κριτήριο το θετικό αποτέλεσμα στη βιολογική δοκιμή στα τοξικά επεισόδια της περιόδου 2006-2007, με υγρή χρωματογραφία υψηλής απόδοσης με φθορισμομετρικό ανιχνευτή (HPLC-FLD), με υγρή χρωματογραφία-φασματογραφία μαζών (LC-MS/MS) και πραγματοποιήθηκε η σύγκριση αυτών με την μέθοδο αναφοράς, τη βιολογική δοκιμή (ΜΒΑ) και β) προσπάθεια εξυγίανσης των επιβαρυμένων οστρακοειδών με τις τεχνικές της ακτινοβόλησης και του οζονισμού. Το ελεύθερο ΟΑ και DTX-1 προσδιορίστηκαν με HPLC-FLD και LC-MS/MS, ενώ οι εστέρες τους προσδιορίστηκαν με LC-MS/MS μετά την αλκαλική υδρόλυση των δειγμάτων. Το όριο ανίχνευσης και ποσοτικοποίησης ήταν 0.015 μg/g ηπατοπαγκέατος (ΗP) και 0.050 μg/g HP αντίστοιχα για την HPLC-FLD και 0.045 μg/g HP και 0.135 μg/g ΗP αντίστοιχα για την LC-MS/MS. Η σύγκριση μεταξύ των δύο αναλυτικών τεχνικών έδειξε άριστη αυμφωνία (100%), ενώ η σύγκριση και των δύο με τη βιολογική δοκιμή έδειξε συμφωνία 97.1%. Με την ακτινοβόληση παρατηρήθηκε μείωση 12-36% για το ελεύθερο ΟΑ, 8-53% για τους εστέρες του ΟΑ και 10-41% για το συνολικό ΟΑ. Με τον οζονισμό παρατηρήθηκε μείωση 6-100% για το ελεύθερο ΟΑ, 25-83% για τους εστέρες του ΟΑ και 21-66% για το συνολικό ΟΑ. Μεγαλύτερη μείωση του ΟΑ παρατηρήθηκε στον ομογενοποιημένο ιστό μυδιού σε σχέση με τα ολόκληρα αποκελυφωμένα μύδια. Σημαντικές διαφορές δεν παρατηρήθηκαν μεταξύ οζονισμένων και μη οζονισμένων μυδιών τόσο οργανοληπτικά όσο και στο ΤΒΑ

Application of a Validated Method for the Identification and Quantification of Mycotoxins in Wines Using UPLC-MS/MS

The aim of the present study was to develop a rapid, simple and reliable method for the identification and quantification of six mycotoxins in wine using liquid chromatography with electrospray ionization tandem mass spectrometry. The analytical method was fully validated, and calibration curves were made with correlation coefficients >0.9970. A short analysis time and acceptable extraction efficiency were achieved by a direct extraction method of analytes (ochratoxin A, aflatoxin B1, B2, G1, G2 and Zearalenone) with acetonitrile. LOD values were from 0.03 to 0.27 μg kg−1, and LOQ values were from 0.08 to 0.81 μg kg−1, with recoveries at various values from 77 to 108%. The expanded uncertainty was 5–21% expressed at a coverage level of k = 2, at a confidence level of approximately 95%. The performance criteria of the method were fully met according to European legislation (EC) 401/2006. The method was successfully applied to wine samples from Cyprus. The method was simple, low cost, quick, accurate, and sensitive

Application of a Validated Method for the Identification and Quantification of Mycotoxins in Wines Using UPLC-MS/MS

The aim of the present study was to develop a rapid, simple and reliable method for the identification and quantification of six mycotoxins in wine using liquid chromatography with electrospray ionization tandem mass spectrometry. The analytical method was fully validated, and calibration curves were made with correlation coefficients >0.9970. A short analysis time and acceptable extraction efficiency were achieved by a direct extraction method of analytes (ochratoxin A, aflatoxin B1, B2, G1, G2 and Zearalenone) with acetonitrile. LOD values were from 0.03 to 0.27 μg kg−1, and LOQ values were from 0.08 to 0.81 μg kg−1, with recoveries at various values from 77 to 108%. The expanded uncertainty was 5–21% expressed at a coverage level of k = 2, at a confidence level of approximately 95%. The performance criteria of the method were fully met according to European legislation (EC) 401/2006. The method was successfully applied to wine samples from Cyprus. The method was simple, low cost, quick, accurate, and sensitive

Valorization of Prickly Pear Juice Geographical Origin Based on Mineral and Volatile Compound Contents Using LDA

In the present work the mineral content and volatile profile of prickly pear juice prepared from wild cultivars was investigated. Fruits used in the study originated from three areas of the Peloponnese Peninsula. Twenty-five macro- and micro-minerals (K, Na, P, Ca, Mg, Al, B, Ba, Be, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Sb, Se, Si, Sn, Ti, Tl, V, Zn) were determined using inductively coupled plasma atomic emission spectroscopy (ICP-OES). Furthermore, analysis of the mineral content of soil samples with ICP-OES showed a perfect correlation with those of fruit juices. Volatile compounds (alcohols, aldehydes, hydrocarbons, terpenoids, and others) were identified using an optimized headspace solid phase microextraction coupled to gas chromatography mass spectrometry (HS-SPME/GC-MS) method. Multivariate analysis showed significant differences (p < 0.05) among the investigated parameters with respect to juice geographical origin. Prickly pear juice samples were classified according to geographical origin by 85.7% and 88.9% using 7 minerals and 21 volatile compounds, respectively

Characterization and botanical differentiation of monofloral and multifloral honeys produced in Cyprus, Greece, and Egypt using physicochemical parameter analysis and mineral content in conjunction with supervised statistical techniques

Thirty-four honey samples donated by beekeepers and purchased from supermarkets were collected during harvesting years 2010-2014 from Cyprus, Greece, and Egypt. The aims of this study were to characterize honey samples and, if possible, to differentiate honeys according to the honey type on the basis of physicochemical parameter values, mineral content, and their combination using supervised statistical techniques (linear discriminant analysis (LDA)). Physicochemical parameters (colour, pH, free acidity, total dissolved solids, salinity, electrical conductivity, and moisture content) were determined according to official methods, while minerals (Al, As, B, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, Hg, Mg, Mn, Mo, Ni, P, Pb, Sb, Si, Ti, Tl, V, and Zn) using inductively coupled plasma optical emission spectrometry. The majority of honey samples analyzed met the quality criteria set by the European directive and national decision related to honey. Implementation of multivariate analysis of variance (MANOVA) and LDA on specific physicochemical parameters, minerals, or their combination provided a satisfactory classification of honeys according to floral type. The overall correct classification rate (based on the cross-validation method) was 79.4% using 7 minerals and 91.2% using 8 physicochemical parameters. When the 15 parameters were combined, the classification rate of Egyptian honeys was improved by 25%

Physicochemical, Spectroscopic and Chromatographic Analyses in Combination with Chemometrics for the Discrimination of Four Sweet Cherry Cultivars Grown in Northern Greece

A total of 56 sweet cherry samples belonging to four cultivars (Ferrovia, Canada Giant, Lapins, and Germersdorfer) grown in northern Greece were characterized and differentiated according to botanical origin. For the above purpose, the following parameters were determined: conventional quality parameters (titratable acidity (TA), pH, total soluble solids (TSS), total phenolic content (TPC), mechanical properties and sensory evaluation, sugars by High Performance Liquid Chromatography (HPLC), volatile compounds by GC/MS, and minerals by ICP-OES. Statistical treatment of the data was carried out using Multivariate Analysis of Variance (MANOVA) and Linear Discriminant Analysis (LDA). The results showed that the combination of volatile compounds and conventional quality parameters provided a correct classification rate of 84.1%, the combination of minerals and conventional quality parameters 86.4%, and the combination of minerals, conventional quality parameters and sugars provided the highest correct classification rate of 88.6%. When the above four cherry cultivars were combined with previously studied Kordia, Regina, Skeena and Mpakirtzeika cultivars, collected from the same regions during the same seasons, the respective values for the differentiation of all eight cultivars were: 85.5% for the combination of conventional quality parameters, volatiles and minerals; and 91.3% for the combination of conventional quality parameters, volatiles, minerals, and sugars

Investigating the impact of botanical origin and harvesting period on carbon stable isotope ratio values (13C/12C) and different parameter analysis of Greek unifloral honeys: A chemometric approach for correct botanical discrimination

The aim of this study was to investigate the impact of botanical origin and harvesting period on carbon stable isotope ratio (13C/12C), colour intensity (CI), radical scavenging activity (%RSA), P and Sn content of Greek unifloral honeys. Thus, twenty-four honey samples were collected during harvesting periods 2011–2012 and 2012–2013, from four different regions in Greece. 13C/12C ratios and minerals were determined using isotope ratio mass spectrometry (IRMS) and inductively coupled plasma optical–emission spectroscopy (ICP-OES), respectively. CI and %RSA were measured using spectrophotometric assays. Results showed that only 13C/12C values and %RSA were affected by both botanical origin and harvesting period (P < 0.05). Applying then chemometric analyses to the collected data set, honeys were correctly classified according to honey type (correct classification rate 87.5% and 79.2% using the original and cross-validation method, respectively). The use of different origin parameters has the potential to aid in honey authentication