Analytical Chemistry for Environment and Food

Analytical Chemistry for Environment and Food Science - 2nd building - 2nd floor	Research Activity
	Staff
Responsible Prof. Giuseppe Scarponi	Equipment
The Analytical Chemistry for Environment and Food laboratory (already former Laboratory of Sea Chemistry) was born in 1998 under the guidance of Prof. Giuseppe Scarponi, previously in the Cost centre and then in the Institute of Marine Sciences. In the year 2003, it joins the Department of Marine Sciences and from 2011 pertains to the new Department of Life and Environmental Sciences. The analytical chemistry laboratory carries out important researches in the field of marine pollution and, more generally, in the environmental field (aerosol, atmosphere, snow and ice, spring water, food, drink) with reference to the presence of heavy metals and organic micro-pollutants. The Department takes part in the National Research Program in Antarctica for which it has made, with its own personnel, ten scientific expeditions to the "White Continent."
Research Activity	Heavy metals in the marine environment: The studies concern the distribution and speciation of Cd, Pb and Cu in the Adriatic Sea and in the Ross Sea in Antarctica. We are looking for anthropogenic effects on various ecosystems and their relationship with the biological activity in the sea. Particular attention is paid to estuarine and coastal environments.
Within the framework of the European Project IMTEC (In-Situ Monitoring of trace metal specification in Estuaries and Coastal zones in relation with the Biogeochemical processes, http://www.idronaut.it/cms/view/research_projects/imtec/s200 ) and of the Marche Region project (DGR 618, 07.05.2003 , CIPE 36/2002 ) on " Speciation of heavy metals in trace amounts in the north-central Adriatic Sea and the relationship with transport processes, bioavailability and human impact " were carried out three oceanographic campaigns in the Adriatic Sea with international participations. The study was conducted along a transect running from the mouth of the Po towards the open sea to the Adriatic centre offshore of Ancona. The aim is to develop a system of continuous monitoring and long-term that can provide, in fairly short time, information on water quality and on the evaluation of the toxicology of marine systems. Furthermore, to determine these heavy metals are used tools that allow voltammetric analysis directly in situ (In situ Voltammetric Profiler, VIP)
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Heavy metals in marine organisms The Laboratory studies the distribution of heavy metals in marine organisms (both Adriatic and Antarctic) and it researches the relationship between bioaccumulation and toxicity. Besides, another aim is to identify sentinel species for various types of pollutants that can serve as biological indicators.
Heavy metals in snow, ice and aerosol of Antarctica The Laboratory studies the changes in the content of heavy metals resulting from the recent global environmental changes in snow and ice cores from Antarctica. Besides, the group is engaged in the distribution of trace elements in the Antarctic aerosol in relation to the sources of impurities it contains. Particular attention is also paid to the fractionation of each pollutant present in Antarctic snow, ice and aerosols to study the relationships between air, snow and ice.
Organic micro-pollutants in the marine environment The Department studies marine pollution caused by various organic micro-pollutants, such as hydrocarbons, polycyclic aromatic hydrocarbons and polychlorinated biphenyls and it searches their distribution in estuarine and coastal environments relating to anthropogenic effects.
Inorganic and organic micro-pollutants in food matrices The Department studies useful or harmful substances in food matrices - such as melamine in Chinese food, proline and 5-hydroxymethyl-2-furaldehyde (HMF) in honey and heavy metals in wine - through the development of new methods and the improvement of the official ones to increase sensitivity, accuracy and precision of the systems used.

Staff
Prof. Giuseppe Scarponi Full Professor 071 220 4514 g.scarponi@univpm.it		Dr. Cristina Truzzi Researcher 071 220 4981 c.truzzi@univpm.it

Dr. Anna Annibaldi

Resarcher

071 220 4981

a.annibaldi@univpm.it

Dr. Silvia Illuminati

post doc

071 220 4981

s.illuminati@univpm.it

Dr. Carolina Finale

PhD student

071 220 4303

c.finale@univpm.it

Equipment
The group has a chemical laboratory with contamination control, "type white chamber (clean room)," ISO 14644-1 Class 6, with areas under ISO Class 5 laminar flow. The laboratory temperature is set at 20 ± 1 ° C during the winter and to 23 ± 1 ° C during the summer. In this laboratory are made all the major decontamination procedures of the various materials and determinations of trace metals in environmental and food matrices. Clean room gowns, masks and gloves are worn by the staff that carefully follows all the procedures laid down for this type of activities during all critical phases of the processing and analysis of sample.

	Anodic stripping voltammetry Voltammetry includes a group of analytical methods by which the information on analytes are obtained through measurements of current relating to the potential applied to a working electrode (mercury, platinum, graphite, mercury film on graphite). Then, with the voltammetric technique, the current-potential curves (voltammograms) are recorded when a scan of potential (excitation signal) has done on an electrode immersed in the interested solution. A thin film electrode of mercury (Thin Mercury Film Electrode, TMFE), deposited on a graphite rotating disk electrode, is used to determine heavy metals. The anodic stripping voltammetry, used with rotary electrode thin film of mercury, is one of the most sensitive techniques currently available for the determination of ultra-traces metals in real samples. The detection limit is about 0.5 ng / L.
	Voltammetric instrumentation
	The voltammetric instrumentation consisted of a Metrohm 746 VA Trace Analyzer specifically developed for the determination of ultra-trace metals and a voltammetric consolle (Metrohm, 747 Va Stand) with the possibility to perform determinations in anodic stripping voltammetry (ASV) with scanning of the potential both in differential pulse mode (Differential Pulse Anodic Stripping Voltammetry, DPASV) and in square wave mode (Square Wave Anodic Stripping Voltammetry, SWASV). The instrumentation is equipped with a Teflon PFA cell (Perfluoroalkoxy alkane polymers) and a system of three-electrode which includes: an Ultra Trace epoxy-impregnated graphite rotating disk working electrode, an Ag/AgCl, 3 mol/L KCl reference electrode (to which all potentials are referred) and a glassy carbon rod counter electrode. The quantifications are made by the multiple standard additions method, which consists of successive additions of standard solutions of known concentration, repeating the measurement after each addition. The quantification is based on the increase in current observed, due to the increase of concentration.
	Voltammetric in situ profiling (VIP) The VIP is a probe that allows performing voltammetric measurements of trace metals directly along the water column. The core of the VIP probe is represented by an integrated microelectrode covered with agarose gel (Gel Integrated Micro Electrode, GIME). It is a composite integrated electrode with a film of mercury deposited on iridium and covered by a membrane of agarose (Agarose Membrane - covered Mercury plated Iridium - based microelectrode array, μ - AMMIA). The microelectrode array is built by coupling the most advanced thin-film micro technology applied to microchips with photolithographic techniques. This consists of an array of 5 x 20 disc iridium microelectrodes each with a diameter of 5 µM and a center – center distance of 150 µM, surrounded by a resin ring EPON SU8 -8. These sensors are covered by a protective membrane made by agarose gel LGL 1.5 %, which prevents problems of fouling, since it allows the diffusion of free ions and labile and mobile complexes with low molecular weight. Meanwhile, they retain colloidal substances and organic macromolecules that could be adsorbed on the electrode surface.

The Atomic absorption spectroscopy The Atomic absorption spectroscopy (AAS) is one of the most used procedures for the qualitative and quantitative determination of chemical trace elements (metals in particular), in different environmental matrices (waters, soil, atmospheric particulate) and in food and metallic alloys, too. In this technique the investigated element is atomized and hit by radiation of appropriate wave length. Due to atomic absorption effect the intensity of luminous ray decreases and this attenuation could be related to the concentration of element in the sample. The analytical chemistry laboratory of DISVA has an Agilent AA Duo 240FS/240Z/UltrAA Package Duo that provides the contemporary use of two different systems of atomization, one for flame (FAAS) and one for graphite furnace (GFAAS), with Zeeman correction of background.
The gas chromatography is a technique that combines the characteristics of gas-liquid chromatography with the mass spectrometry ones, to identify different substances into the sample. The instrumentation consists of two principal elements: the gas-chromatography and the mass spectrometry that, interfaced, offer a better identification of substances.
The gas chromatography (GC) is a technique based on the separation of different substances between a stationary and a mobile phase, depending on the affinity of each compound with the stationary phase. The stationary phase is generally made of a non-volatile liquid, fastened on powder that uniformly fills a column (called “packed column”), or distributed as thin layer film (few m) on internal wall of column, length > 10m and external diameter < 1 mm (capillary column). The mobile (and moving) phase is a gas, called “carrier-gas” (generally an inert gas, helium, nitrogen or argon). The sample, introduced into the column (packed column) and treated with a constant flow of carrier gas, is separated into its components in function of their affinity for the stationary phase. The elute sample is collected by a detector that shows the chromatogram of compound that is the graph that display the signal generated by the detector in function of the time; this graph is a sequence of peaks of different amplitude and height placed along the time axis. Analyzing the retention time of each peak is possible to identify the elute compound; from the peaks’ area or height is possible to determine the concentration or the absolute quantity of various compounds of the sample, depending on the detector used. The detector in the GC-MS technique is a mass spectrometer.

Instruments for the treatment of samples		Instrument for the sampling

Microwave oven A microwave system ( MARS 5) of the CEM Corp. (Matthews, NC, USA) is used for the digestion of samples of organisms or for the extraction of different organic compounds; it is equipped with a carousel of 14 vessels made of Teflon PFA (HP-500 Plus, 100 mL), resistant to high pressures.	UV digester For the photoxidative digestion of the samples a UV digester Metrohm (Herisau, Switzerland), mod. 705 is used; it is equipped with twelve tubes (12 mL quartz vessels) and with a 500 W mercury lamp.	GO-FLO bottle A GO-FLO bottle (General Oceanics, Florida) is used for the sampling of seawater along the water column. This bottle presents a closed-open-closed mechanism; at a depth of approximately 10 m, it automatically opens due to the hydrostatic pressure; once it reaches (through the winch) the depth of sampling,it is closed by a messenger (mod. 1000 - MG).	High volume sampler for aerosol For the sampling of atmospheric particulate material, the group has 2 Teflon-coated, brushless volumetric flow controlled, high-volume sampler (Tish Model TE-6070-BL, Tish Environmental Inc., Village of Cleves, Ohio).

Measurement of the main chemical, physical and biological parameters

Multiparametric probe (CTD) For the chemical physical Oceanographic measurements a multiparametric probe CTD Ocean Seven mod. 316 (Idronaut, Brugherio, MI) is used; it allows the determination in situ of salinity, temperature, conductivity, pH, dissolved oxigen, redox potential and chlorophyll.	Turbidimeter The group has a portable turbidimeter Orbeco-Helige Mod 966 for measuring the turbidity of the water samples.		Microanalytical balance The group has a computerized electronic micro-analytical balance Mettler AT216 (0.01mg resolution, repeatability Ds = 0.015 mg) for accurate weighing.	System for producing ultrapure water The water used in laboratory for the preparation of standard solutions, for washing the materials and for the general purposes of the laboratory, has been produced through a Millipore Midi system with a treatment in two stages, which produces respectively deionized water in the first stage (Elix ) and ultrapure water in the second one (Milli-Q).

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