G. D'Ascenzo

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.

Food analyses: A new calorimetric method for ascorbic acid (Vitamin C) determination

The analysis of the ascorbic acid (vitamin C; A.A.) contained in some foodstuff and pharmaceutical samples was performed by a new microcalorimetric method. It uses the oxidation of the vitamin C catalysed by the enzyme ascorbate oxidase (A.O.), which gets the specificity of the reaction. The calibration curve was built under the following operative conditions: 25.00 degrees C, pH 5.6, [A.O.]=11 IU ml(-1), the linearity range is: 3</=A.A.</=270 mg l(-1). The method has been applied to many samples to determine the vitamin C quantity. Each analysis takes about 20 min (the assay time is instead about 5 min, the slow step is due to the time necessary for the calorimeter to return to the operative temperature after washing). No pre-treatments of the samples are requested, unless their solubilisation in buffer. The variations of vitamin C concentration were studied in function of storage time and light exposition. Using a known HPLC assay to compare its reliability on a drug analysis has validated the proposed method.

Vapor pressure measurements of ferrocene, mono- and 1,1′-di-acetyl ferrocene

Abstract By using different techniques the vapor pressure of ferrocene, mono-acetyl ferrocene and 1,1′-di-acetyl ferrocene was measured. The following pressure—temperature equations were derived ferrocene log P(kPa)= 9.78 ± 0.14 − (3805 ± 46)/T mono-acetyl ferrocene log P(kPa) = 14.83 ± 0.14 − (5916 ± 48)/T 1,1′-di-acetyl ferrocene log P(kPa) = 8.82 ± 0.11 − (4289 ± 44)/T By second- and third-law treatment of the vapor data the ΔH0sub,298 = 74.0 ± 2.0 kJ mole−1 for the sublimation process of ferrocene was calculated and compared with the literature data. For the sublimation enthalpy of mono- and 1,1′-di-acetyl ferrocene the values ΔH0sub,298 = 115.6 ± 2.5 kJ mole−1 and ΔH0sub,298 = 91.9 ± 2.5 kJ mole−1 were derived by second-law treatment. Thermal functions of these compounds were also estimated.

Thermal properties of some compounds of lutidinic acid with divalent metals

Abstract The thermal properties of the complexes of lutidinic acid with several divalent metal ions were determined by thermogravimetry (TG) and differential thermal analysis (DTA). The complexes precipitate from aqueous solution as hydrated 1:1 complexes. On heating in air, hydrate water is lost first, followed by total disruption of the anhydrous complex to yield the metal oxide; in a nitrogen atmosphere, the pattern is similar, but final weight constancy is not achieved. The thermal stability of the metal complexes is in the order: Mn(II)>Fe(II)>Co(II)≅ Zn(II)>Ni(II)>Cu(II) The different metal-ligand ratio in the solid state for analogous compounds with isocinchomeronic acid is discussed.

Complexes of divalent metal ions with cinchomeronic and dinicotinic acid thermal properties

Abstract The thermal properties of the complexes of cinchomeronic and dinicotinic acid with several divalent metal ions were determined by thermogravimetry (TG) and differential thermal analysis (DTA). For the thermal stability of the anhydrous compounds a sequence may be observed for the metal ions with cinchomeronic (3,4-H 2 PC) and dinicotinic acid (3,5-H 2 PC): The thermal stability of the pyridine carboxylic acid for each metal of the series is: dinicotinic > cinchomeronic The activation energy values for each thermal reaction were also calculated, using the Coats and Redfern algorism, by the Univac 1108 computer, by a program properly implemented for the statistical analysis of the data to obtain the reaction order and the activation parameters with the relative confidence limits.

Complexes of cobalt(II), nickel(II) and copper(II) with the benzenedicarboxylic acids. Thermal properties

Abstract The thermal properties of the complexes of phthalic, isophthalic and terephthalic acid with cobalt(II), nickel(II) and copper(II) are determined by thermogravimetry (TG), differential thermogravimetry (DTG) and differential scanning calorimetry (DSC). The thermal stability of the anhydrous compounds gives, for the metal ions, a sequence Co > Ni > Cu. The thermal stability series as a function of the ligand for each metal is terephthalate > isophthalate > phthalate.

Simultaneous determination of base/neutral and acid herbicides in natural water at the part per trillion level

SummaryA new method for the simultaneous identification and quantification of base/neutral and acidic pesticides at a low nanogram per liter concentration level in natural waters is presented. The method includes enrichment of the compounds by solid phase extraction on graphitized carbon black, followed by sequential elution of the base/neutral and acidic pesticides. Identification and quantification of the compounds is performed with HPLC-ESI-MS. This procedure involves passing 1 L of ground water and 2 L of drinking water samples through a 0.5 g graphitized carbon black (GCB) extraction cartridge. A conventional 4.6-mm-i.d. reversed phase LC C-18 operating with a 1 mL min−1 flow of the mobile phase was used to chromatograph the analytes. A flow of 100 μL min−1 of the column effluent was diverted to the ESI source. The ESI source was operated in positive ion mode for base/neutral pesticides and in negative-ion mode for acid pesticides. For the analyte considered, the response of the mass detector was linearly related to the amount of the analytes injected between 5 and 250 ng. In all cases, recoveries of the analytes were better than 90%. The limit of detection (signal-to-noise ratio=3) of the method for the pesticides considered in drinking water samples was estimated to be about 3–10 ng L−1.

Determination of organophosphorus pesticides and metabolites in crops by solid-phase extraction followed by liquid chromatography/diode array detection

SummaryA multiresidue method for the analysis of 28 common organophosphorus pesticides and 3 of their main metabolites (paraoxon-ethyl, paraoxon-methyl and malaoxon) in a variety of crop samples has been developed. An aliquot of the chopped sample is homogenized with an organic solvent. The efficiency of extraction methods using methanol, acetone and acetonitrile was evaluated. The acetonitrile gives higher recoveries and minimizes co-extractives from the samples matrix.The resulting aqueous acetonitrile extract is filtered and cleaned by solid phase extraction (SPE). For SPE three different types of adsorption materials (Carbograph 1, LiChrobut-EN and Amberchrom CG-161m) were compared. The cleaned-up extract is injected into the LC system.Three different analytical columns were tested in conjunction with two mobile phase compositions of different polarity.The use of LC-DAD techniques allowed the identification of both organophosphorus pesticides and metabolites by means of standard and spectral comparison, respectively.The accuracy of the quantitative determination measured in terms of average percentage recovery of 31 compounds in crop samples was 61–96% with a relative standard deviation of 5–10%.

Thermoanalytical study of benzimidazole complexes with transition metal ions: Copper (II) complexes

Abstract The benzimidazole molecule (Benz) is known to play a fundamental role in many biological systems; it is moreover, extensively used in industrial processes as a corrosion inhibitor for metal and alloy surfaces. The synthesis and the thermal profile of some Cu (II) complexes of benzimidazole of general formula CuBenz 4 X 2 are proposed. A parallel study of these complexes with an ionization mass spectrometer is also reported.

Coordination compounds of biological interest: thermal properties of some compounds of saccharin (o-benzoic sulfimide) with divalent metal ions

The thermal properties of cobalt(II) and copper(II) complexes of saccharin (sacc) (o-benzoic sulfimide) have been studied, and are compared with those of ternary complexes of cobalt(II) and copper(II) having both saccharin and pyridine as ligands. The thermal behaviour is discussed in terms of the bonds between the central ion and the ligands. The frequency shifts of the carbonyl and sulfonyl groups support the hypotheses derived from the thermal data. The thermal stability scale CO(II) /s> Cu(II) is always obtained while the stability constant scale is CO(II) < Cu(II).