Roberto Samperi

FATE OF NATURAL ESTROGEN CONJUGATES IN MUNICIPAL SEWAGE TRANSPORT AND TREATMENT FACILITIES

The aim of this study was to investigate the fate of the conjugated forms of the three most common natural estrogens in the municipal aqueous environment. Levels of conjugated and free estrogens in (1) female urine; (2) a septic tank collecting domestic wastewater; (3) influents and effluents of six activated sludge sewage treatment plants (STPs) were measured. The analytical method was based on solid-phase extraction by using a Carbograph 4 cartridge and Liquid Chromatography-tandem Mass Spectrometry. On average, a group of 73 women selected to represent a typical cross section of the female inhabitants of a Roman condominium, excreted 106, 14 and 32 microg/day of conjugated estriol (E(3)), estradiol (E(2)) and estrone (E(1)), respectively. Apart from some E(3) in pregnancy urine, free estrogens were never detected in urine samples. Estrogen sulfates represented 21% of the total conjugated estrogens. This situation changed markedly in the condominium collecting tank. Here, significant amounts of free estrogens were observed and the estrogen sulfate to estrogen glucuronated ratio rose to 55/45. A laboratory biodegradation test confirmed that glucuronated estrogens are readily deconjugated in unmodified domestic wastewater, presumably due to the large amounts of the beta-glucuronidase enzyme produced by fecal bacteria (Escherichia coli). Deconjugation continued in sewer transit. At the STP entrance, free estrogens and sulfated estrogens were the dominant species. The sewage treatment completely removed residues of estrogen glucuronates and with good efficiency (84-97%) the other analytes, but not E(1) (61%) and estrone-3-sulfate (E(1)-3S) (64%). Considering that (1) E(1) has half the estrogenic potency of E(2), (2) the amount of the former species discharged from STPs into the receiving water was more than ten times larger than the latter one and (3) a certain fraction of E(1)-3S could be converted to E(1) in the aquatic environment, E(1) appears to be the most important natural endocrine disrupter.

Recent developments in matrix solid-phase dispersion extraction

Matrix solid-phase dispersion is a sample preparation strategy widely applied to solid, semisolid or viscous samples, including animal tissues and foods with a high lipidic content. The process consists in blending the matrix onto a solid support, allowing the matrix cell disruption and the subsequent extraction of target analytes by means of a suitable elution solvent. First introduced in 1989, MSPD employment and developments are still growing because of the feasibility and versatility of the process, as evidenced by the several reviews that have been published since nineties. Therefore, the aim of the present review is to provide a general overview and an update of the last developments of MSPD.

Monitoring aromatic surfactants and their biodegradation intermediates in raw and treated sewages by solid-phase extraction and liquid chromatography.

On the basis of solid-phase extraction, a simple procedure for determining simultaneously two aromatic surfactant classes, i.e., linear alkylbenzene sulfonates (LAS) and nonylphenol polyethoxylates (NPEO), as well as their biodegradation intermediates in raw and treated sewages is presented. This procedure involved passing 10 and 100 mL of an influent and effluent water sample, respectively, through a 1-g graphitized carbon black (GCB) extraction cartridge. By exploiting the presence of positively charged active centers on the GCB surface, we succeeded in fractionating the complex mixture of the analytes considered by differential elution. The first fraction contained NPEO and nonylphenol (NP)

Reversed-phase high-performance liquid chromatographic determination of linear alkylbenzene sulphonates, nonylphenol polyethoxylates and their carboxylic biotransformation products

Abstract The possibility was investigated of simultaneously determining linear alkylbenzene sulphonates, nonylphenol polyethoxylates and their respective biotransformation products, namely sulphophenyl carboxylates (SPC) and nonylphenoxy carboxylates, by reversed-phase high-performance liquid chromatography with UV and fluorescence detection. Both the ion-suppression and the ion-pair techniques were taken into account for separating the compounds of interest. Each technique exhibited peculiar characteristics of resolution and sensitivity. Differences in the selectivity of the chromatographic system on using either methanol or acetonitrile as organic modifier were also considered. Liquid-solid extraction by an octadecyl-bonded silica (C 18 ) cartridge was employed to isolate all the compounds considered from a sewage treatment plant effluent sample. The recovery of SPC with up to six carbons in the carboxylate chain was unsatisfactory. The SPC distribution appeared to be dominated by the homologues having 5–8 carbon atoms in the carboxylate chain.

Evaluation of graphitized carbon black as a selective adsorbent for extracting acidic organic compounds from water

Abstract By a simple and rapid treatment, graphitized carbon black (GCB) can be made to act as both a reversed phase and an anion exchanger. The base—neutral/acid fractionation of organic species extracted from water with a GCB cartridge can be easily achieved by differential elution, provided that the pKa values of the acidic species are not higher than about 7. A tetramethylammonium hyroxidebasified solvent mixture is the most effective eluent for the rapid elution from a GCB extraction cartridge of any kind of organic acid. The subfractionation of acidic species can be easily performed on the basis of their acidity strength by passing sequentially through a GCB cartridge various solvent mixtures containing suitable phase modifiers. The ability of a GCB extraction cartridge to retain organic acids was unaffected by the ionic strength of the water sample. The influence of fulvic acids dissolved in water on the capability of GCB to extract acidic compounds and isolate them from co-extracted base—neutral species was evaluated. The advantage of using a GCB cartridge over that containing a chemically bonded silica for accurately determining acidic compounds is demonstrated by two practical applications.

Multiclass mycotoxin analysis in food, environmental and biological matrices with chromatography/mass spectrometry.

Mold metabolites that can elicit deleterious effects on other organisms are classified as mycotoxins. Human exposure to mycotoxins occurs mostly through the intake of contaminated agricultural products or residues due to carry over or metabolite products in foods of animal origin such as milk and eggs, but can also occur by dermal contact and inhalation. Mycotoxins contained in moldy foods, but also in damp interiors, can cause diseases in humans and animals. Nephropathy, various types of cancer, alimentary toxic aleukia, hepatic diseases, various hemorrhagic syndromes, and immune and neurological disorders are the most common diseases that can be related to mycotoxicosis. The absence or presence of mold infestation and its propagation are seldom correlated with mycotoxin presence. Mycotoxins must be determined directly, and suitable analytical methods are necessary. Hundreds of mycotoxins have been recognized, but only for a few of them, and in a restricted number of utilities, a maximum acceptable level has been regulated by law. However, mycotoxins seldom develop alone; more often various types and/or classes form in the same substrate. The co-occurrence might render the individual mycotoxin tolerance dose irrelevant, and therefore the mere presence of multiple mycotoxins should be considered a risk factor. The advantage of chromatography/mass spectrometry (MS) is that many compounds can be determined and confirmed in one analysis. This review illustrates the state-of-the-art of mycotoxin MS-based analytical methods for multiclass, multianalyte determination in all the matrices in which they appear. A chapter is devoted to the history of the long-standing coexistence and interaction among humans, domestic animals and mycotoxicosis, and the history of the discovery of mycotoxins. Quality assurance, although this topic relates to analytical chemistry in general, has been also examined for mycotoxin analysis as a preliminary to the systematic literature excursus. Sample handling is a crucial step to devise a multiclass analytical method; so when possible, it has been treated separately for a better comparison before tackling the instrumental part of the whole analytical method. This structure has resulted sometimes in unavoidable redundancies, because it was also important to underline the interconnection. Most reviews do not deal with all the possible mycotoxin sources, including the environmental ones. The focus of this review is the analytical methods based on MS for multimycotoxin class determination. Because the final purpose to devise multimycotoxin analysis should be the assessment of the danger to health of exposition to multitoxicants of natural origin (and possibly also the interaction with anthropogenic contaminants), therefore also the analytical methods for environmental relevant mycotoxins have been thoroughly reviewed. Finally, because the best way to shed light on actual risk assessment could be the individuation of exposure biomarkers, the review covers also the scarce literature on biological fluids.

Rapid-resolution liquid chromatography/mass spectrometry for determination and quantitation of polyphenols in grape berries.

A rapid-resolution liquid chromatography/mass spectrometric (RRLC/MS) method for detection and quantitation of polyphenols in grape berry skins and seeds has been developed. Pulp-free berry skins were treated with liquid nitrogen and ground; seeds were also ground. Then, 3 g of samples were extracted with 30 mL of a mixture of methanol/water/formic acid 70:30:1 (v/v/v) under sonication and 1 microL of the final extract was injected into two 100 x 2.1 mm i.d., 1.8 microm Zorbax Eclipse plus C18 columns connected in series. Compounds were fractionated using a gradient elution of acidified acetonitrile/methanol 50:50 (v/v)/water. Columns were thermostatted at 70 degrees C. MS was carried out on an Agilent 6410 QqQ instrument equipped with an electrospray ionization source. Positive and negative MS/MS product ion scans were used for compound identification, whereas positive full scan MS in the m/z range 200-1400 was used for quantitation. By means of mass spectra comparison, various flavonols, flavan-3-ols, anthocyanins and stilbenes were identified. Quantitation was performed by external calibration, and concentration values were corrected for matrix effect that was evaluated in separate experiments. Semi-quantitative estimation was performed for compounds for which standards were not commercially available. Recoveries ranged from 90-102% with relative standard deviation (RSD) <5%, whereas the between samples RSD was in the range 4-12%. Two surrogate standards were used for quality control. The developed method was applied to analyze the polyphenol content of three Vitis vinifera table cultivars at physiological maturity and after proper preservation for 6 weeks. Results demonstrated that during preservation about half of the polyphenol content was lost.

Flavonoids: chemical properties and analytical methodologies of identification and quantitation in foods and plants

Flavonoids have been recognised as one of the largest and most widespread groups of plant secondary metabolites, with marked antioxidant properties. The general name flavonoid refers to a class of more than 6500 molecules based upon a 15-carbon skeleton. In this paper a general overview of flavonoids, their classification, structures and analytical methods for their determination is presented.

Multiresidue Herbicide Analysis in Soil: Subcritical Water Extraction with an On-Line Sorbent Trap

We evaluated the feasibility of extracting selectively and rapidly herbicide residues in soils by hot water and collecting analytes with a Carbograph 4 solid-phase extraction (SPE) cartridge set on-line with the extraction cell. Phenoxy acid herbicides and those nonacidic and acidic herbicides which are often used in combination with phenoxy acids were selected for this study. Five different soil samples were fortified with target compounds at levels of 100 and 10 ng/g (30 ng/g of clopyralid and picloram) by following a procedure able to mimic weathered soils. Herbicides were extracted with water at 90 °C and collected on-line by the SPE cartridge. After the cartridge was disconnected from the extraction apparatus, analytes were recovered by stepwise elution to separate nonacidic herbicides from acidic ones. The two final extracts were analyzed by liquid chromatography/mass spectrometry with an electrospray ion source. At the lowest spike level considered, analyte recoveries ranged between 81 and 93%, except those for 2,4-DB and MCPB, which were 63%. For 16 herbicides out of 18, the ANOVA test showed recoveries were not dependent on the type of soil. The method detection limit was in the 1.7-10 ng/g range. For the analytes considered, method comparison showed this extraction method was overall more efficient than Soxhlet and sonication extraction techniques.

Evaluation of two new examples of graphitized carbon blacks for use in solid-phase extraction cartridges

Abstract The performances of two new examples of graphitized carbon blacks (GCBs), Carbograph 4 and Carbograph 5, filling solid-phase extraction cartridges were evaluated. Compared to an older GCB, Carbograph 1, the two new GCBs exhibited far larger abilities in extracting very polar compounds from both 4 l of drinking water and 1 l of water containing an amount of humic materials equivalent to 20 mg/l dissolved organic content. Like older GCB material, the new examples of GCBs have on their surfaces anion-exchange adsoprtion sites. However, Carbograph 5 partly failed to isolate acidic species from co-extracted non-acidic species by stepwise elution. Moreover, the surface of this sorbent material is more contaminated than those of both Carbograph 1 and 4 by sites able to bind irreversibly particular adsorbates. The extraction efficiencies of the two new GCBs were also compared with those of two recently introduced polystyrene-divinylbenzene (PS-DVB)-based materials. Recovery data showed that the carbonaceous materials were abler than PS-DVB ones in isolating very polar compounds from large water volumes, such as phenol, water-soluble pesticides, and low-molecular-mass biointermediates of linear alkylbenzenesulfonate surfactants. The positive features of including Carbograph 4 extraction cartridges in analytical schemes for determining traces of very polar pollutants in natural waters are demonstrated by three practical applications.