DNA damage in A549 cells exposed to different extracts of PM(2.5) from industrial, urban and highway sites.

The aim of this research is to investigate the role played by the chemical fraction of PM(2.5) in the DNA damage induction in human lung cells (A549): in particular the effects of samples collected in urban, industrial and highway sites were compared. Organic and water-soluble extracts of PM(2.5) were analysed to quantify PAHs (by GC-MS technique) and metals (by ICP-MS technique) and tested on A549 cells to evaluate, by the Comet assay (without and with Fpg enzyme), genotoxic and oxidative damage. The chemical analysis showed a variability of PAH composition in PM organic extracts of the three different sites and pointed out the presence of 14 metals (being Fe, Cu, Zn, Sb and Ba the most abundant) in all the PM water extracts. Regarding the biological effect, all the PM(2.5) organic extracts caused a significant dose-dependent increase of the A549 DNA damage. The genotoxic effect was related to the PM(2.5) PAH content and the highest effect was observed for the highway site sample. The DNA oxidative damages were observed for the PM(2.5) water extracts of the samples collected in industrial and highway sites. The extent of the oxidative damage seems to be related to the kind and concentration of the metals present. The results of this study emphasize the importance of PM chemical composition on the biological effects and highlight the need, when evaluating the effects on health and exposure management, to always consider, beside size and concentration of PM, also their qualitative composition.

The use of clays to sequestrate organic pollutants. Leaching experiments.

Leaching experiments are performed from clay-pollutant systems in order to evaluate the capability of clays to sequestrate organic pollutants from wastewaters. Reference kaolinite KGa-1b, montmorrillonite SWy-2 and reference soil BCR-700 are the sorbent materials. 2,4,6-trichloroaniline (2,4,6-TCA) and 4-chlorophenol (4-CP) are the typical pollutants, sorbed at amounts of 10.0 mg g(-1) and 5.8 mg g(-1) on SWy-2 and 7.3 mg g(-1) and 2.2 mg g(-1) on KGa-1b, respectively. The leaching agents are ultrapure water and model solutions of acid rain and surface waters that simulate meteoric leaching. 1.0mM HNO(3), 1.0mM H(2)SO(4) solutions and a methanol/water 50/50 (v/v) mixture simulate leaching agents of industrial source. The results are compared and the preferential capability of the clays to sequestrate the more lipophilic 2,4,6-TCA is evidenced. The bond interactions are discussed and explained through preferential adsorption reactions. For montmorrillonite also a simultaneous intercalation in the phyllosilicate interlayer is proposed.

Photodegradation of E110 and E122 dyes in a commercial aperitif. A high performance liquid chromatography-diode array-tandem mass spectrometry study.

A commercial aperitif containing E110 and E122 dyes is exposed to photo-irradiation in solar box under conditions chosen to simulate sun light irradiation. After 16 days of irradiation the red-coloured aperitif assumes a very pale yellow colour. HPLC-diode array-MS/MS analysis evidences the presence in the commercial aperitif of some impurities with naphthalene-based structures. The structures for the photodegradation products are proposed.

A new hydrophilic interaction liquid chromatography tandem mass spectrometry method for the simultaneous determination of seven biogenic amines in cheese.

An HILIC-PI APCI MS/MS method is developed for the determination of seven biogenic amines (cadaverine, histamine, putrescine, spermidine, spermine, tryptamine and tyramine) in cheese. Their presence and relative amounts give useful information about freshness, level of maturing, quality of storage and cheese typicization. The major drawback in the analysis is represented by the relevant matrix effect and the general unbalanced concentrations of the different amines in cheese. The method proposed represents an improvement with respect to an HPLC-MS/MS method already developed in this laboratory. The new method permits better sensitivities it makes use of a Waters Atlantis HILIC (150.0 mm x 2.1 mm i.d., 3 microm) stationary phase and of a mobile phase of acetonitrile and ammonium formate 50.0 mM in ultrapure water brought to pH 4.00 for formic acid, flowing under gradient conditions. The chromatographic system is interfaced with a 3200QTrap LC-MS/MS system (Applied Biosystem, Foster City, CA, USA) by a Turbo V interface equipped with Heated Nebuliser (APCI) and Turbo Ion Spray (TIS) probes. LOQ values lower than 10 microg L(-1) are obtained. The method is applied in the analysis of Castelmagno cheese.

High performance liquid chromatography/tandem mass spectrometry determination of biogenic amines in typical Piedmont cheeses.

The paper presents a new HPLC method, hyphenated with mass spectrometry detection, for the separation and determination of the biogenic amines that are most commonly present in cheese, namely cadaverine, histamine, spermidine, spermine, tyramine and tryptamine. The HPLC-MS/MS method is validated by comparison of the results with those obtained through a literature HPLC-UV determination, based on a pre-column dansyl chloride derivatisation step. The intercalibration is based on the statistical t-test for multiple samples that allows to compare simultaneously the results obtained with the two methods for more analytes and to decide, at a prefixed confidence level, if the two methods are inter-changeable. The new HPLC-MS/MS method, employed in selected reaction monitoring (SRM) mode, permits to achieve for standard solutions limit of detection (LOD) values ranging from 1.7 to 22.5 microg L(-1) and LOQ (limit of quantitation) values ranging from 5.6 to 68.2 microg L(-1). In order to apply the method in the analysis of cheeses, LOD and LOQ values have also been evaluated in "ricotta" cheese, in order to take as possible into account the matrix interference. In these conditions LODs range between 5.1 and 35.0 microg L(-1) and LOQs between 14.2 and 101.2 microg L(-1). The whole methodology, comprehensive of the homogenization-extraction process and HPLC-MS/MS analysis, has been applied in the analysis of three typical Piedmont (North-West Italy) cheeses, known as Toma Piemontese, Raschera and Castelmagno.

HPLC-MSn and GC-MS methods to study sunlight and UV-lamp degradations of 1-amino-5-naphthalene sulfonate.

HPLC-DAD, HPLC-MS/MS, GC-MS and spectrophotometric methods are employed to investigate the degradation process of sodium 1-amino-5-naphthalene sulfonate (1A5NS) aqueous solutions, when exposed to sunlight and UV-lamp (254 nm) irradiations. Experimental results show that both sunlight and 254 nm UV-lamp irradiations destroy the chemical and give rise to major degradation products, characterised by the same m/z ratios. Degradation times are lower for sunlight irradiation, for which a t(1/2) value of 137.4 min has been evaluated, in comparison with the value of t(1/2) of 26.8 min, observed for UV-lamp irradiation. The degradation pathway and the structures of the degradation products are proposed.

Sorption of pesticides on kaolinite and montmorillonite as a function of hydrophilicity.

Pesticides and other organic species are adsorbed by soil via different mechanisms, with bond strengths that depend on the properties of both the soil and the pesticide. Since the clay fraction in soil is a preferential sorbent for organic matter, reference kaolinite and montmorillonite are useful models for studying the mechanism and the strength of sorption. This paper presents the results of batch experiments to investigate the interactions of kaolinite KGa-1 and montmorillonite SWy-1 with the following pesticides and organic species resulting from the natural degradation of pesticides in the environment: atrazine (1-chloro-3-ethylamino-5-isopropylamino-2,4,6-triazine), simazine (1-chloro-3,5-bisethylamino-2,4,6-triazine), diuron [1,1-dimethyl-3-(3,4-dichlorophenyl)urea], aniline, 4-chlorophenol, 2,4-dichlorophenol, and 2,4,6-trichlorophenol. Each of these chemicals has different hydrophilicity. Systems containing 2.0 g of clay were put in contact with 100.0 mL of solutions of the pesticides at known concentration ranging from 1.0 to 5.0 mg/L, and the amount of solute adsorbed was evaluated through RP-HPLC analysis of the pesticide still present in the aqueous suspension. To test for electrostatic interactions between the clay surface and the pesticides, potentiometric titration was used to determine the permanent surface charge of clays. Experiments were performed at different pH values. The results indicate that, for the chemicals studied, neutral molecules are preferentially retained relative to ionized ones, and that montmorillonite is a more effective sorbent than kaolinite.

HPLC-UV and HPLC-MSn multiresidue determination of amidosulfuron, azimsulfuron, nicosulfuron, rimsulfuron, thifensulfuron methyl, tribenuron methyl and azoxystrobin in surface waters.

The paper presents a new HPLC method, with UV and MS(n) detection, for the determination of seven pesticides, including the sulfonylurea herbicides amidosulfuron, azimsulfuron, nicosulfuron, rimsulfuron, thifensulfuron methyl, tribenuron methyl, and the fungicide azoxystrobin characterised by a methoxyacrilate structure. The methodology consists of a preconcentration/SPE (solid phase extraction) step and HPLC-UV (240 nm detection wavelength)-MS(n) analysis. Under the optimised conditions and after a 1000/1 preconcentration factor, the limits of detection were lower than 14.5 ng L(-1) for UV detection and lower than 8.1 ng L(-1) for MS detection. The limits of quantification were lower than 48.3 ng L(-1) in UV detection and than 26.9 ng L(-1) in MS(n) detection. The analysis of two samples, spiked with a mixture of the pesticides at threshold level concentrations, gave more than 60% recovery.

Statistical evaluation of recovery of 3,4-dichloroaniline in soil as function of particle size and analyte concentration.

A great mean value of recovery for extraction of 3,4-dichloroaniline from a soil is calculated from individual recovery values evaluated for four different fractions of the soil. Then the uncertainty associated to this great mean recovery is calculated and used to know whether to apply or not the correction in routine analysis performed for the same kind of soil and the same analyte. The most representative fractions that, as a function of particle size, can be identified in a soil are: sand (2.000-0.063mm), coarse silt (0.063-0.020mm), fine silt (0.020-0.002mm) and clay (

Sorption studies of chloroanilines on kaolinite and montmorillonite.

Batch experiments have been performed in order to evaluate the ability of the two reference clays kaolinite (KGa-1) and Na-montmorillonite (SWy-1) to retain three representative chloroanilines: 3-chloroaniline, 3,4-dichloroaniline and 2,4,6-trichloroaniline. Systems containing the clay mineral and the pollutant solution (at concentration levels ranging between 1.0 and 10.0mg/L) were considered and RP-HPLC methods were employed to follow the sorption processes as a function of time. The results indicate that montmorillonite shows a general higher sorption capacity with respect to kaolinite and that for both the reference clays, in the concentration range investigated, the amount of pollutant sorbed increases with concentration. The sorption coefficient K(d) ranges between 0.0030 L/g for the system 3-chloroaniline-kaolinite and 0.0488L/g for the system 2,4,6-trichloroaniline-montmorrillonite. The most lipophilic trichloroaniline shows the greater sorption. X-ray analyses suggest for kaolinite a preferential sorption onto the mineral surface, while for montmorillonite a progressive swelling of the structure is observed, likely due to sorption processes that also take place in the interlayer.

Oxidative degradation of food dye E133 Brilliant Blue FCF Liquid chromatography-electrospray mass spectrometry identification of the degradation pathway.

This paper is devoted to the evaluation of the degradation pathway of the E133 Brilliant Blue FCF (C.I. 42090) that is largely used in the food industry. The degradation is studied in oxidation conditions obtained by addition of potassium persulfate at different persulfate to dye molar ratios under natural sunlight irradiation. The degradation pathway of the dye passes through a species coloured in dark blue and then gives rise to uncoloured species. Due to the low volatility and the poor thermal stability of the dye, reversed-phase liquid chromatography associated to mass spectrometry and tandom mass spectrometry was employed to follow the kinetics of degradation and identify some intermediates. The identification of organic species still present in the decoloured dye and the value of COD obtained in these conditions show evidence that complete decolorization does not correspond to complete mineralisation. No direct information of toxicity is available for the uncoloured degradation products but the further formation of aromatic amines can not be excluded.

Optimization by experimental design and artificial neural networks of the ion-interaction reversed-phase liquid chromatographic separation of twenty cosmetic preservatives.

Particular attention are recently receiving antimicrobial agents added as preservatives in hygiene and cosmetics commercial products, since some of them are suspected to be harmful to the human health. The preservatives used belong to different classes of chemical species and are generally used in their mixtures. Multi-component methods able to simultaneously determinate species with different chemical structure are therefore highly required in quality control analysis. This paper presents an ion interaction RP-HPLC method for the simultaneous separation of the 20 typical antimicrobial agents most used in cosmetics and hygiene products, that are: benzoic acid, salicylic acid, 4-hydroxybenzoic acid, methyl-, ethyl-, propyl-, butyl-, benzyl-benzoate, methyl-, ethyl-, propyl-, butyl-, benzyl-paraben, o-phenyl-phenol, 4-chloro-m-cresol, triclocarban, dehydroacetic acid, bronopol, sodium pyrithione and chlorhexidine. For the development of the method and the optimization of the chromatographic conditions, an experimental design was planned and models were built by the use of artificial neural network to correlate the retention time of each analyte to the variables and their interactions. The neuronal models developed showed good predictive ability and were used, by a grid search algorithm, to optimize the chromatographic conditions for the separation of the mixture.

Intercalibration of chromatographic methods for auxino phytodrugs in Solanaceae.

Three chromatographic methods are considered for the determination in Solanaceae of auxino-similar phytodrugs, so called because their structure resembles an auxine plant hormone. The phytodrugs studied were: 2,4-dichlorophenoxyacetic acid, 2,4-dichlorophenoxypropionic acid, 2,4-dichlorophenoxybutyric acid, 2-methyl-4-chlorophenoxyacetic acid, 2,4,5-trichlorophenoxyacetic acid, naphthylacetic acid and 2-naphthyloxyacetic acid. Three chromatographic methods, respectively based on ion-interaction HPLC, GC-MS with intra-injector derivatisation and CC-MS with pre-injection derivatisation, were developed, optimised and validated. A comparative discussion of the advantages/disadvantages of the methods suggests a strategy for their preferential use, that is essentially a function of the matrix complexity.

Simultaneous reversed-phase high-performance liquid chromatographic separation of mono-, di-and trichloroanilines through a gradient elution optimised by experimental design.

A new RP-HPLC method for the simultaneous determination of the 13 mono-, di- and trichloroanilines has been developed. In order to obtain the analyte resolution within an acceptable analysis time, a gradient elution program has been optimised through the use of an experimental design and a grid search algorithm. The optimized conditions provided the resolution of all the analytes in less than 80 min. The primary validation of the analytical method gave limit of detection values ranging between 0.02 and 0.06 mg/l and very good linearity of the calibration curves.

A simplex-optimized chromatographic separation of fourteen cosmetic preservatives: analysis of commercial products.

An ion-interaction high-performance liquid chromatography (HPLC)-diode-array detection method is developed and optimized for the separation of typical antimicrobial agents used in cosmetics and hygiene products. The most used preservatives contain different molecular structures, different functionalities, and are characterized by different chemical properties. Organic acids, alkyl esters of benzoic acids, alkyl p-hydroxy benzoic acids (parabens), phenol derivatives, and carbanilides represent the most used preservatives, and are often present in multicomponent mixtures. In order to develop a multicomponent method to be used in quality control analysis, the ion-interaction reagent reversed-phase HPLC technique seems to be particularly suitable, because it allows for the simultaneous separation of acidic, basic, and neutral species. The experimental conditions of the method are developed by OVAT (one variable at a time) treatment and further optimized by a multivariate approach based on a Simplex algorithm that works on a desirability function targeted to maximize the resolution in a multicomponent mixture. The new method proposed that is able to simultaneously separate fourteen preservatives is applied in the analysis of commercial products.

Ion interaction reagent reversed-phase high-performance liquid chromatography determination of anti-tuberculosis drugs and metabolites in biological fluids.

New methods of ion interaction reagent (IIR) RP-HPLC are presented for the determination of anti-tuberculosis drugs and their metabolites, singly or in multi-component mixtures, in biological fluids. The following analytes are considered: isoniazid, ethionamide, pyrazinamide, morphazinamide, p-aminosalicylic acid, nicotinic and isonicotinic acids. Aqueous solutions of three different ion interaction reagents are alternatively or comparatively used as the mobile phases, namely: (A) 5.00 mM octylamine at pH 3.00 for o-phosphoric acid, (B) 5.00 mM octylamine at pH 8.00 for o-phosphoric acid, and (C) 5.00 mM 1,6 diaminohexane at pH 6.00 for o-phosphoric acid. The response linearity between peak area and analyte concentration is verified for all the analytes in the concentration range within the determination limits and 2.00 mg/l. Detection limits are always lower than 82 microg/l for standard solutions; in the analysis of samples of rat serum, rat plasma and human serum, the matrix effect is negligible, the detection limits are always lower than 94 microg/l and the average recovery yield is always greater than 96%.

New strategies for the determination of phenylurea pesticides by gas chromatography with hot splitless inlet systems.

Direct gas chromatographic methods to analyse phenylurea pesticides are discouraged by the thermal instability of these compounds, that in conventional hot splitless inlet systems leads to extensive and irreproducible formation of isocyanates and amines. However a careful control of the operating conditions, like the inlet temperature, the pressure and the presence of suitable chemical additives (as acetic acid, low-molecular-mass amines, organic anhydrides) can either: (i) minimise the thermal decomposition enabling the direct GC-MS analysis of phenylureas, or (ii) lead to reproducible conversion to isocyanates. Experimental design was employed to study the effect of the experimental variables on the thermal transformation of phenylurea pesticides in splitless inlet system. Two strategies were alternatively optimised: (i) the minimisation of degradation reactions to increase the signal of phenylureas; (ii) the maximisation of the degradation to isocyanates that are in turn determined. The maximal yields in isocyanate were obtained with high inlet temperatures, low carrier flows in the injection phase and the presence of acetic anhydride. By contrast, the use of relatively low inlet temperatures, high carrier flows during the injection and the presence of an amine maximise the response of the parent compounds.

Optimization of the separation of mono- and dichloroanilines in ion interaction high-performance liquid chromatography.

To optimize the ion-interaction chromatographic separation of nine chloroaniline isomers, the effect on retention of six experimental parameters is investigated by means of multivariate analysis. The factors considered are the organic modifier concentration in the mobile phase; the length of the alkyl chain of the alkylammoniumion salts used as the ion-interaction reagents (IIRs); the concentration of IIRs; the pH of the mobile phase, the flow-rate and the ionic strength. The use of fractional factorial and star designs allowed one to draw out useful information on the retention mechanism involved and to build a model characterized by both descriptive and predictive ability. Concerning descriptions, the results suggest a retention mechanism mainly based on reversed-phase partition, while the main role of the alkylamine (used as IIR) seems to mask the activity of the residual silanol groups on the stationary phase. As a result efficiency is improved. For prediction purposes, the regression models allow the optimization of the chromatographic separation, as regards both resolution and total analysis time. The study allowed one to develop a method able to separate the nine mono- and dichloroanilines in a total analysis time within 66 min and with detection limits ranging from 4.0 to 21.0 microg/l.

Determination of creatinine in human serum. Statistical intercalibration of methods.

An intercalibration of methods was performed in the determination of creatinine in human plasma. Jaffè, enzymatic creatinine-deaminase (CRDI) and ion-interaction reagent high-performance liquid chromatography (HPLC) methods were employed and the results were compared using a parametric t-test for multiple samples and non-parametric Mann-Whitney, Wilcoxon and Friedman tests. The comparison did not show a statistically significant difference in the use of the three methods. The ion-interaction HPLC procedure is proposed as a reference method for creatinine assays.

High-performance liquid chromatography of food colours and its relevance in forensic chemistry.

The forensic interest in the use of food colours is related to health rights and safeguard of the consumer, as established in national legislations. The regulations related to food dyes consider the health of human beings and the adulteration of foodstuffs and economic needs connected with quantitative restrictions on imports. Efficient analytical methods are required for evaluating toxicity and authenticity or adulteration, in order (a) to determine whether there are synthetic dyes present in foods and whether they are permitted, (b) to determine the levels, (c) to confirm the absence of added dyes in foods where they are not declared and (d) to check on the stability of dyes during processing and storage. Recent HPLC methods for the identification and determination of natural and synthetic dyes and of carcinogenic amines contained as impurities in synthetic dyes are reviewed.