Monitoring of biogenic amines in food is important for quality control, in terms of freshness evaluation and even more for food safety. A novel and cost-effective method was developed and validated for the determination of the main biogenic amines: histamine, putrescine, cadaverine, spermidine and spermine in fish tissues. The method includes extraction of amines with perchloric acid, pre-column derivatization with Pyrene Sulfonyl Chloride (PSCl), extraction of derivatives with toluene, back-dissolution in ACN after evaporation and determination by reversed phase high performance liquid chromatography with UV and intramolecular excimer fluorescence detection. The structure of the pyrene-derivatives was confirmed by liquid chromatography–mass spectrometry with electrospray ionization. The standard addition technique was applied for the quantitation due to significant matrix effect, while the use of 1,7-diaminoheptane as internal standard offered an additional confirmation tool for the identification of the analytes. Method repeatability expressed as %RSD ranged between 7.4–14% for the different amines and recovery ranged from 67% for histamine up to 114% for spermine. The limits of detection ranged between 0.1–1.4 mg kg⁻¹ and the limits of quantification between 0.3–4.2 mg kg⁻¹. The method was applied to canned fish samples and the concentrations of the individual biogenic amines were below the detection limit up to 40.1 mg kg⁻¹, while their sum was within the range 4.1–49.6 mg kg⁻¹.

Pesticides have been used in large amounts around the world for decades and are responsible for environmental pollution and various adverse effects on human health. Analysis of untreated wastewater can deliver useful information on pesticides’ use in a particular area and allow the assessment of human exposure to certain substances. A wide-scope screening method, based on liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry, was applied, using both target and suspect screening methodologies. Daily composite influent wastewater samples were collected for seven or eight consecutive days in Athens between 2014 and 2020 and analyzed for 756 pesticides, their environmental transformation products and their human metabolites. Forty pesticides were quantified at mean concentrations up to 4.9 µg/L (tralkoxydim). The most abundant class was fungicides followed by herbicides, insect repellents, insecticides and plant growth regulators. In addition, pesticide transformation products and/or metabolites were detected with high frequency, indicating that research should be focused on them. Human exposure was evaluated using the wastewater-based epidemiology (WBE) approach and 3-ethyl-carbamoyl benzoic acid and cis-1,2,3,6-tetrahydrophthalimide were proposed as potential WBE biomarkers. Wastewater analysis revealed the presence of unapproved pesticides and indicated that there is an urgent need to include more transformation products in target databases.

Ethephon is approved in the European Union as a plant growth regulator and used in plant protection products. The available methods for the assay of ethephon in pesticide formulations demand decomposition of ethephon to ethene under alkaline conditions, and subsequently either titration by acidimetry or gas chromatography with flame ionization detection. The present work proposes two novel anion exchange high-performance liquid chromatographic methods with indirect spectrophotometric detection for the assay of ethephon in plant protection formulations, with a quick and simple sample preparation, involving only weighing and diluting the sample with water before injection. The study involved optimization of the pH, the concentration of a chromophore compound as the mobile phase modifier and the optimization of the mobile phase flow rate. The first method used a strong anion exchange column (250 mm × 4 mm, 10 µm, 300 Å) with isocratic elution with an aqueous mobile phase consisted of 1 mM potassium hydrogen phthalate at pH 7 by the addition of 0.6 M aqueous KOH using a 1.4 mL/min flow rate. The second approach also used a strong anion exchange column (250 mm × 4.6 mm, 5 µm, 80 Å) with isocratic elution with an aqueous mobile phase composed of 1.2 mM phthalic acid, 6 mM monopotassium phosphate and 4% (v/v) methanol at pH 2 by the addition of H₃PO₄ and 2 mL/min flow rate. The two methods were validated, applied in commercial samples and were shown to be equivalent after statistical comparison. They are considered applicable for the quality control of ethephon content in soluble concentrate formulations and surpass the existing laborious and time-consuming methods which demand decomposition of ethephon to ethene.

The determination of volatile compounds is essential for the chemical characterisation of honey's aroma and its correlation to its sensory profile and botanical origin. The present study describes the development, optimization and validation of a new, simple and reliable method for the determination of volatile compounds in honey using headspace solid-phase microextraction combined with gas chromatography/mass spectrometry (HS-SPME-GC-MS). The optimization of the SPME conditions showed that the ratio of honey: water (2:1) and the incubation temperature (60 °C) are the most critical parameters. Gas chromatography was performed with medium polar Varian CP-Select 624 column and the experimental Retention Index for a number of compounds was determined as an additional identification feature for suspect analysis. The simultaneous use of four internal standards chlorobenzene, benzophenone, 2-pentanol and 4-methyl-2-pentanone and matrix matched calibration enhanced method accuracy achieving recoveries 73–114 % and repeatability ranging between 3.9 and 19 % relative standard deviations. Furthermore, the superiority of the HS-SPME to static head space technique was verified exhibiting four-to nine-fold higher sensitivity. Target and suspect screening were applied to 30 Greek honey samples and 53 volatile compounds belonging to different chemical classes, such as alkanes, aldehydes, ketones, alcohols, and esters were identified with quantified concentrations ranging between 3.1 μg kg⁻¹ (Limonene) up to 20 mg kg⁻¹ (Benzeneacetaldehyde). Among the new findings is the detection of Myrtenol in Greek pine honey and 2,3-butanediol in Greek oak honey. The developed analytical protocol can be a valuable tool in order to chemically characterize honey based on the volatile content.