Christophoros E Christophoridis

• Chemistry
• PostDoc Position at National Centre of Scientific Research "Demokritos"

This study investigates the sustainable management and utilization of water resources in the fruit processing industry, focusing on a case study from the EU-funded ULTIMATE project. Conducted in a juice factory in Nafplio, Greece, the primary objective is to explore the recovery of polyphenols from water by-product streams generated during orange j...

In the past, the application of TiO2 slurry reactors has faced difficulties concerning the recovery and reusability of the catalyst. In response to these challenges, immobilized photocatalyst systems have been investigated, wherein the catalyst is fixed onto a solid support, frequently with reduced photocatalytic performance. In the present study,...

This study aimed on the development of a SPE-UHPLC-MS/MS method for the simultaneous determination of pesticide residues in drinking water samples. A chemometric approach was applied to optimize the efficiency of the SPE pretreatment procedure. This study involved (i) the application of a Full Factorial Design for the screening of the significant f...

In recent decades, tattooing has become a form of social and artistic expression. To apply a tattoo, the skin is marked by the internal injection of ink in the skin. Hence, it includes human health exposure to metals since the tattoo ink composition includes such elements. The present paper reports the determination and quantification of 8 elements...

Aesthetic aspects of drinking water, such as Taste and Odor (T&O), have significant effects on consumer perceptions and acceptability. Solving unpleasant water T&O episodes in water supplies is challenging, since it requires expertise and know-how in diagnosis, evaluation of impacts and implementation of control measures. We present gaps, challenge...

Low back pain is a major chronic musculoskeletal disorder, caused mainly due the degeneration of the intervertebral discs (IVDs). Bisphosphonates (BPs), like zoledronic acid (ZOL), are used in osteoporosis management; however, their accumulation in the IVDs and their physiological role has not been addressed so far. To this end, an SPE-liquid chrom...

Contemporary wastewater reclamation units entail several diverse treatment and extraction processes, with a multitude of monitored quality characteristics, controlled by a variety of key operational parameters directly affecting the efficiency of treatment. The conventional optimization of this highly complex system is time- and energy- consuming,...

This study presents the photolytic and photocatalytic degradation of antineoplastic drug etoposide (ETO) in aqueous solutions under UV irradiation. Photolytic degradation of ETO was slow with insufficient mineralization. The quantum yield of ETO’s photolytic degradation was calculated and ranged from 0.00029 to 0.00275 mol Einstein⁻¹. Photocatalyti...

Lake Karaoun is the largest artificial lake in Lebanon and serves multiple purposes. Recently, intensive cyanobacterial blooms have been reported in the lake, raising safety and aesthetic concerns related to the presence of cyanotoxins and cyanobacterial taste and odor (T&O) compounds, respectively. Here, we communicate for the first time results f...

Water radiolysis can serve as a useful tool to study the degradation of organic pollutants in water. Manipulation of the radiolytic system enables the selective production of reactive species (RS) with known yields. Our aim was to explore the effects of the radiolytically produced RS on commonly occuring water taste and odor compounds (T&O), 2-meth...

Cyanotoxins (CTs) produced by cyanobacteria in surface freshwater are a major threat for public health and aquatic ecosystems. Cyanobacteria can also produce a wide variety of other understudied bioactive metabolites such as oligopeptides microginins (MGs), aeruginosins (AERs), aeruginosamides (AEGs) and anabaenopeptins (APs). This study reports on...

This study presents the development of an analytical method for the simultaneous determination of multiclass illicit drugs (cocainoids, opiates, amphetamines, and cannabinoids) and psychoactive pharmaceuticals (anxiolytics, hypnotics, antipsychotics, antidepressants, and antiparkinsonian), in municipal wastewater. The analytical method was validate...

This study focused on the photolytic and photocatalytic degradation of the antineoplastic drug irinotecan (IRI) in aqueous solutions. Photocatalysis was carried out using commercial TiO2 (Degussa P25) and several operational parameters were studied. Identification and structure elucidation of TPs were carried out with the complementary use of SPE-L...

The objectives of the present study were: a) to evaluate the photocatalytic degradation of two benzodiazepine pharmaceuticals, alprazolam and diazepam, using Photo-Fenton, b) to optimize the experimental parameters through a central composite experimental design, c) to assess their mineralization and toxicity variations and d) to identify the trans...

The presence of phosphorus (P) and heavy metals (HMs) in surface sediments originating from lakes Volvi, Kerkini, and Doirani (N. Greece), as well as their fractionation patterns, were investigated. No statistically significant differences in total P content were observed among the studied lakes, but notable differences were observed among sampling...

Conventional treatment processes for the removal of cyanobacteria and cyanotoxins are thoroughly described in this chapter, including chemical treatment (heavy metals, herbicides, and photosensitizers), coagulation/flocculation combined with air flotation, and various adsorption processes.

Advanced oxidation processes (AOPs) have become significant and attractive technologies for the removal of cyanotoxins and cyanobacteria in contaminated waters due to their outstanding performance in this field. Details are presented in this chapter regarding the introduction of each AOP and important studies and applications of different AOPs for...

Background and aims: Wastewater-based epidemiology is an additional indicator of drug use that is gaining reliability to complement the current established panel of indicators. The aims of this study were to: (i) assess spatial and temporal trends of population-normalized mass loads of benzoylecgonine, amphetamine, methamphetamine and 3,4-methylen...

Cyanobacteria are a diverse group of photosynthetic Gram-negative bacteria that produce an array of secondary compounds with selective bioactivity against a broad spectrum of organisms and cell lines. In this study, 29 strains isolated from freshwaters in Greece were classified using a polyphasic approach and assigned to Chroococcales, Synechococca...

Surface marine sediments act as important repository of heavy metals (HMs) and play a significant role in their transport and possible release. The anthropogenic contribution to heavy metal contamination and the associated ecological and health risks should be evaluated in studied areas. The objectives of this study were to investigate the presence...

Contamination of dairy products with heavy metals is a major concern on a global scale and human exposure to related food products, especially cheese, is of rising concern. The aim of this study was the determination of several heavy metals (As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se and Zn) in 15 cheese samples consumed in Greece, during March 2016. A...

Abstract Toxic cyanobacteria occur in Greek surface water bodies. However, studies on the occurrence of cyanotoxins (CTs) are often limited to mainly microcystins (MCs), with use of screening methods, such as ELISA, that are not conclusive of the chemical structure of the CT variants and can be subject to false positive results. A multi-lake survey...

A one-year sampling campaign of road dusts was carried out at 10 distinct sites in the broader area of the city of Thessaloniki, Greece and concentrations of heavy metals (HMs) along with magnetic susceptibility were evaluated. The concentrations of HMs in road dusts were higher than their local background values, while magnetic parameters indicate...

The scope of this study was the development, optimization and validation of an analytical method for the determination of selected heavy metals and trace elements (As, Hg, Se, Cd, Cu, Pb, Mn, Fe, Ni, Zn, Cr) in milk powder, using microwave-assisted digestion. A statistical experimental design approach using central composite design (CCD) was carrie...

This paper presents the first report of cyanobacteria and cyanotoxins from the South Caucasus region, in particular from Lake Yerevan (Armenia). Microcystis, Dolichospermum, and Planktothrix were the key genera identified during the growing season. A trend of a remarkable increase in cyanobacterial densities was observed from 2012 to 2013 exhibitin...

This study presents the development of a worldwide inter-laboratory testing scheme for the analysis of seven illicit drug residues in different matrices (standard solutions, tap- and wastewater). By repeating this exercise for six years with participation of 37 laboratories from 25 countries, the testing scheme was substantially improved based on e...

Advanced Oxidation Processes (AOPs) that rely on the efficient generation of reactive radical species increasingly attract greater interest with respect to their application to water remediation from a wide variety of organic micropollutants concerning human health or the environment.

Photo-Fenton has emerged as a prominent strategy for the treatment of drugs and their metabolites. Benzodiazepines and their metabolites represent a significant group of emerging environmental pollutants due to their stability, continuous discharge in the environment and their low removal rates by conventional biological wastewater treatment plants...

Water radiolysis is known as an Advanced Oxidation Process (AOP) for treatment of organic pollutants but it can also serve as a useful tool to study the effects of highly reactive species that are commonly present in AOPs. Such studies are carried out in simpler homogeneous systems that can be manipulated with use of scavengers to selectively produ...

In the present study, an investigation of the mineralogy and morphology, the heavy metal content and the health risk of urban road dusts from the second largest city of Greece was conducted. For this reason road dust samples from selected sites within the city core area were collected. No differences were observed in the mineralogy of road dusts co...

p>Lake Karla (Central Greece) is a unique example - at European scale - of a shallow lake ecosystem that was dried in the 1960s and in 2009 started to be restored. The lake is listed in the network of the Greek protected areas as it is considered a vital aquatic ecosystem, in terms of biodiversity. It has, however, already been adversely affected b...

During the past 20 years, the elucidation of biosynthetic pathways of cyanotoxins and the development of analytical chemistry tools have shed light into cyanotoxin production in aquatic ecosystems. Analyses of cyanobacteria have shown that along with MCs other cyanotoxins as well as other bioactive compounds may be produced by a single strain. Ther...

Planktonic Nostocales cyanobacteria represent a challenge for microbiological research because of the wide range of cyanotoxins they synthesize and their invasive behavior, which is presumably enhanced by global warming [1]. In this study, eight strains representing six Nostocalean taxa (Anabaenopsis elenkinii, Cylindrospermopsis raciborskii, Sphae...

The occurrence and ecotoxicology of cyanobacteria are well documented in freshwater habitats, however studies in marine environments have not been carried out to the same extent. To date, toxicity has been reported in marine cyanobacteria belonging to the genera Oscillatoria, Synechococcus, Synechocystis, and there are scarce records for Leptolyngb...

This study focused on (a) the development of a screening methodology, in order to determine the main experimental variables affecting chlorinated and brominated disinfection by-product (DBP) formation in water during chlorination experiments and (b) the application of a central composite design (CCD) using response surface methodology (RSM) for the...

Cyanobacterial and algal toxins comprise a large group of harmful metabolites, belonging to different chemical classes, with a variety of chemical structures, physicochemical properties and toxic activities. In this study, a fast, simple and sensitive analytical method was developed for the simultaneous determination of multi-class cyanobacterial a...

The cyanobacterium Aphanizomenon favaloroi was identified for the first time in Europe in the Mediterranean brackish Lake Vistonis during July–August 2014. It formed a dense bloom (from 16 × 10⁶ to 81 × 10⁶ trichomes L–1), causing a brown colouration of the lake water. When A. favaloroi formed 100% of the total phytoplankton biomass (44 mg L–1), sa...

Exposure to β-N-methylamino-l-alanine (BMAA) might be linked to the incidence of amyotrophic lateral sclerosis, Alzheimer’s disease and Parkinson’s disease. Analytical chemistry plays a crucial role in determining human BMAA exposure and the associated health risk, but the performance of various analytical methods currently employed is rarely compa...

Exposure to β-N-methylamino-L-alanine (BMAA) might be linked to the incidence of amyotrophic lateral sclerosis, Alzheimer's disease and Parkinson's disease. Analytical chemistry plays a crucial role in determining human BMAA exposure and the associated health risk, but the performance of various analytical methods currently employed is rarely compa...

Acetate- and citrate-buffered quick, easy, cheap, effective, rugged, safe (QuEChERS) pretreatment methods were evaluated for the determination of various pesticides in peaches, grapes, apples, bananas, pears, and strawberries from various regions of Greece, using LC-MS/MS. The purposes of this study were (i) to evaluate which type of QuEChERS metho...

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Summary A novel method for the simultaneous determination of 24 pesticides in water was optimized using an experimental design procedure. The effect of various experimental SPE factors on the selected response (recovery) was studied. Tested SPE factors were: sample pH, sample volume, two step elution with eluents A (MeOH:MTBE) and B (CH2Cl2), % for...

Cyanotoxins are compounds produced by numerous cyanobacterial species, with different chemical structures and physicochemical properties. Due to their widespread distribution and high toxicity, they pose a threat to public health. The objective of the CYANOWATER PROJECT in the frame of ARISTEIA, is to fill current research gaps in the areas of cyan...

Cyanobacteria are considered a rising environmental problem, since under favorable conditions, they can form extensive algal blooms and produce a wide range of cyanotoxins, which pose a significant risk to aquatic habitats and human health. Anatoxin-a (ANA) and Cylindrospermopsin (CYN), are two important cyanotoxins, often found in water bodies wor...

Polyoxometalates (POMs) have been employed in the past as electron scavengers in connection with photo-excited TiO2 to decrease charge recombination, due to their similar electronic characteristics [1-3], although in a limited scale regarding the material preparative methods and characterization. The present study investigates the preparation and c...

The present work describes the application of an analytical procedure, utilizing ultra performance liquid chromatography (UPLC) coupled with mass spectrometry instrumentation, for the determination of 253 multiclass pesticides, classified in six different groups. Solid phase extraction was applied for the isolation and pre-concentration of target c...

The aims of this study were (a) to evaluate the degradation of acetamiprid with the use of Fenton reaction, (b) to investigate the effect of different concentrations of H2O2 and Fe(2+), initial pH and various iron salts, on the degradation of acetamiprid and (c) to apply response surface methodology for the evaluation of degradation kinetics. The k...

The EU Water Framework Directive (WFD) has established new regulations for the registration and quality monitoring of water bodies. The concept of the directive is to introduce a holistic management approach, which brings together interdisciplinary scientific knowledge for the achievement of high water quality, and to ensure the creation of a harmo...

A simple vortex-assisted liquid-liquid microextraction protocol followed by GC-MS is proposed for the determination of 12 organophosphate pesticides residues in environmental water samples and wines. The sample pretreatment employs the usage of low-density organic solvent. The parameters affecting the extraction efficiency (type and volume of organ...

Road dust samples were collected from the historical center of the city of Thessaloniki, the second largest city of Greece and one of the largest urban and industrial centers of the Balkans. Road dusts were collected from 8 selected sites in the city core, containing accumulated matter from the edges of major roads. Samples were pretreated using ch...

Sampling ErrorsOverview of the Types of SamplingQualitative SamplingSampling PlansStatistical Sampling of SolidsQuality Assurance in Sampling20,21ReferencesFurther Reading

In the present study the combination of morphological, geochemical and magnetic methods was used to characterize urban road dust properties of the city of Thessaloniki, the second largest of Greece and one of the largest urban agglomerations in the Balkans. Samples of road dust were collected from the accumulated matter at the edges of major roads...

The EU Water Framework Directive (WFD) has established new regulations for the registration and quality monitoring of water bodies. The concept of the directive is to introduce a holistic management approach, which brings together interdisciplinary scientific knowledge for the achievement of high water quality, and to ensure the creation of a harmo...

The purpose of this paper is the geochemical study of the waters of the Bogdanas river, and especially the concentration of heavy metals and organic substances. The results show that the river is polluted, particularly with heavy metals Pb, Zn, Cr, Cd and As, which in certain cases exceed the established limits. The high content of Cr is probably a...

Forty sediment samples and fifteen water samples were collected from the Gulf of Thermaikos and the Bay of Thessaloniki in order to determine the concentration of Zn, Cu, Pb and Cr and measure various seawater parameters. The level of pollution attributed to heavy metals was evaluated using several pollution indicators in order to determine anthrop...

In this study, the heterogeneous photocatalytic degradation of prometryn using TiO(2) as photocatalyst was investigated. The main objectives of the study were: (I) to evaluate the kinetics of the pesticide disappearance, (II) to compare the photocatalytic efficiency of two different types of TiO(2), (III) to examine the influence of various paramet...

Laboratory studies were conducted to determine the effect of pH and redox conditions, as well as the effect of Fe, Mn, Ca, Al, and organic matter, on the release of ortho-phosphates in lake sediments taken from Lakes Koronia and Volvi (Northern Greece). Results were evaluated in combination with experiments to determine P fractionation in the sedim...

The general profile of the pollution of drinking water, originating from groundwater, by nitrates, chloride and arsenic, in the Prefecture of Thessaloniki, was studied in this project. Samples (tap water) were collected from 52 areas-villages of the Prefecture, during a period of 6 months. The analytical results were related to certain points on th...