Fate of diuron and linuron in a field lysimeter experiment.

The environmental fate of herbicides can be studied at different levels: in the lab with disturbed or undisturbed soil columns or in the field with suction cup lysimeters or soil enclosure lysimeters. A field lysimeter experiment with 10 soil enclosures was performed to evaluate the mass balance in different environmental compartments of the phenylurea herbicides diuron [3-(3,4-diclorophenyl)-1,1-dimethyl-urea] and linuron [3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea]. After application on the agricultural soil, the herbicides were searched for in soil, pore water, and air samples. Soil and water samples were collected at different depths of the soil profile and analyzed to determine residual concentrations of both the parent compounds and of their main transformation products, to verify their persistence and their leaching capacity. Air volatilization was calculated using the theoretical profile shape method. The herbicides were detected only in the surface layer (0-10 cm) of soil. In this layer, diuron was reduced to 50% of its initial concentration at the end of the experiment, while linuron was still 70% present after 245 d. The main metabolites detected were DCPMU [3-(3,4-dichlorophenyl)-1-methylurea] and DCA (3,4-dichloroaniline). In soil pore water, diuron and linuron were detected at depths of 20 and 40 cm, although in very low concentrations. Therefore the leaching of these herbicides was quite low in this experiment. Moreover, volatilization losses were inconsequential. The calculated total mass balance showed a high persistence of linuron and diuron in the soil, a low mobility in soil pore water (less than 0.5% in leachate water), and a negligible volatilization effect. The application of the Pesticide Leaching Model (PELMO) showed similar low mobility of the chemicals in soil and water, but overestimated their volatilization and their degradation to the metabolite DCPMU. In conclusion, the use of soil enclosure lysimeters proved to be a good experimental design for studying mobility and transport processes of herbicides in field conditions.

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.

Method development for measuring trace levels of penicillins in aqueous environmental samples.

A method based on liquid chromatography/mass spectrometry with an electrospray ion source and a single quadrupole instrument (LC/ES-MS) has been developed for determining trace levels of eight widely used penicillins in aqueous environmental samples. Analyte extraction was performed from 4 L tap water, 2 L groundwater, 1 L river water, 0.2 L treated sewage and 0.1 L raw sewage, by using a Carbograph 4 cartridge. During removal of the solvent, penicillins were purposely allowed to convert into their penicilloyl methyl esters. This 'in situ' derivatization step resulted in a dramatic enhancement of the response of the ES-MS system for non-amphoteric penicillins. Analyte recoveries were better than 80% irrespective of the type of aqueous sample, with the exception of amoxicillin (76%) and ampicillin (77%) in tap water. At the level of 50 ng/L of each analyte in ground water, the within-day precision was in the range 6-10%. Calibration curves were linear for injected amounts up to 800 ng, with R(2) in the range 0.9952-0.9995. When injecting large equivalent volumes of the aqueous samples, the electrospray matrix effect altered in-source collision-induced dissociation (CID) spectra of the analytes by severely weakening signals for fragment ions, as compared to spectra of reference standards. Remedies to obviate this anomalous unwelcome effect are suggested. On the basis of a signal-to-noise ratio of 10, limits of quantification were estimated to range between 2 (cloxacillin) and 24 ng/L (amoxicillin) in river water.

Solid-phase extraction followed by liquid chromatography-mass spectrometry for trace determination of beta-lactam antibiotics in bovine milk.

A confirmatory assay able to unambiguously identify and quantify 10 approved-for-use beta-lactam antibiotics in milk below stipulated U.S. and EU tolerance levels is presented. beta-Lactams are extracted from 10 mL of intact milk by a Carbograph 4 cartridge. After solvent removal, residue reconstitution, and filtration, a completely transparent and uncolored extract is injected into a liquid chromatography -mass spectrometry (LC-MS) instrument equipped with an electrospray (ES) ion source and a single quadrupole. During the chromatographic run, the ES/MS system is operated first in the positive-ion mode (PI) and then in the negative-ion (NI) mode. This is done to circumvent matrix interferences resulting in remarkable signal weakening of the last-eluted analytes, when detecting them as [M+H]+ adduct ions. MS data acquisition is performed by a time-scheduled three-ion selected ion monitoring program. At the 5 ng/mL level, recoveries of the beta-lactams are between 70 (nafcillin) and 108% (cephalin), with relative standard deviations ranging between 5 (oxacillin) and 11% (amoxicillin and ceftiofur). The response of the ES/MS detector is linearly related to injected amounts up to 500 ng, irrespective of the chemical characteristics of the beta-lactams and the acquisition mode selected (PI or NI modes). Limits of quantification, based on a minimal value of the signal-to-noise ratio of 10, were estimated to be within 0.4 (cephalin) and 3 ng/mL (dicloxacillin). Analyses of milk samples taken after intramammary application of amoxicillin showed that 1.2 ng/mL of this penicillin was still present 6 days after treatment. At this concentration level, the identification power of the method is not weakened, as signals of the three product ions of amoxicillin are still well distinguishable from the background noise.

Hot phosphate-buffered water extraction coupled on-line with liquid chromatography/mass spectrometry for analyzing contaminants in soil.

We evaluated the feasibility of analyzing rapidly traces of polar and medium polar contaminants in soil by coupling on-line a hot phosphate-buffered water extraction apparatus to a liquid chromatography/mass spectrometer system. Coupling was accomplished by using a small C-18 sorbent trap for collecting analytes and two six-port valves. The efficiency of this device was evaluated by extracting 13 selected pesticides from 200 mg of laboratory-aged soils by varying the extraction temperature, the extractant volume, and the flow rate at which the extractant passed through the extraction cell and the sorbent trap. In terms of extraction efficiency, robustness of the method, and extraction time, the best compromise was that of using 8 mL of extractant at 90 degrees C and 0.5 mL/min flow rate. Under these conditions, recoveries of 11 out of 13 analytes ranged between 82 and 103%, while those of the least hydrophilic pesticides, i.e., neburon and prochloraz, were 73 and 63%, respectively. By increasing the extractant volume to 60 mL, additional amounts of the two latter compounds could be recovered. Under this condition, however, the most hydrophilic analytes were in part no more retained by the C-18 sorbent trap. From a naturally 1.5-year aged soil, hot phosphate-buffered water removed larger amounts of three herbicides and hydroxyterbuthylazine (a terbuthylazine degradation product) than pure water and Soxhlet extraction. This result seems to confirm that hot phosphate buffer is also able to remove from soil those fractions of contaminants that, on aging, are sequestered into the humic acid framework.

Estimating steroid oestrogen inputs into activated sludge treatment works and observations on their removal from the effluent.

A method to predict steroid oestrogen inputs into sewage works is described and tested against available data. For oestradiol (E2), 68% of the predictions were within 50% of the actual measured value, and for oestrone (E1), 52% of the estimations were within 50% of the measured value. Predictions for ethinyloestradiol (EE2), which are particularly sensitive to assumptions on the number of people taking the oral contraceptive, were less accurate. Five Italian and three Dutch activated sludge treatment works (STW) were sampled on two to three occasions for E2, E1, EE2 and E3 (E3 only in Italy) in both influent and effluent waters. High concentrations of E3 were found in the influent, as predicted, with a mean of 57 ng/1 and a mean of 10 ng/l in the effluent. Using the currently available data collected from composite samples, an average of 88% of E2 and 74% of E1 would appear to be removed by the activated sludge process.

Simultaneous determination of acidic and non-acidic pesticides in natural waters by liquid chromatography-mass spectrometry.

There is increasing interest and demand for real multi-residue methods able to simultaneously determine pesticides with a broad spectrum of chemical characteristics in environmental and biological matrices. A method based on solid-phase extraction with a Carbograph 4 cartridge and liquid chromatography with electrospray mass spectrometry (LC-ES-MS) enabling simultaneous determination of non-acidic and acidic pesticides in real water samples is described. On repeatedly (n=5) extracting 4 l of drinking water (spike level 50 ng/l), 2 l of ground water (spike level 100 ng/l) and 1 l of river water (spike level 200 ng/l), recovery of 26 base/neutral pesticides and 13 acidic pesticides were equal to or better than 80%, except for carbendazim (67%), butocarboxim (73%), aldicarb (75%) and molinate (77%). Relative standard deviations ranged between 4 and 15%. Final extracts containing acidic and non-acidic pesticides were analyzed in a single chromatographic run while the ES-MS system was operated in both positive and negative ion modes. With the aim of finding the best operating conditions, in terms of sensitivity, the pH of the LC eluent was varied in the 2.9-8.4 range. Altogether, the best results were obtained by using an LC eluent containing 1 mmol/l formic acid. Over the entire pH range considered, well shaped peaks for both basic and acidic analytes were achieved by the use of a new generation LC column. By extracting selected ion current profiles from the total ion current mass chromatogram relative to analysis of 4 l of drinking water spiked with 50 ng/l of each of the 39 analytes, estimated limits of detection ranged between 0.05 and 1.5 ng/l, except for propyzamide (8 ng/l) and 2,4-DB (3 ng/l).

Quantification of phenylurea herbicides and their free and humic acid-associated metabolites in natural waters.

There is increasing interest in and demand for simultaneously monitoring pesticides as well as related degradation products (DPs) in natural waters, as the latter compounds can be even more toxic than the former ones. A method for determining parts per trillion levels of phenylurea herbicides and their DPs, that is their dealkylated forms and aromatic amines, is described. This method is based on solid-phase extraction with a Carbograph 4 cartridge followed by liquid chromatography (LC) with electrospray (ES) mass spectrometric detection. A study aimed at optimizing the response of the ES-MS detector for very weakly basic chloroanilines was conducted. Results showed that ion signal intensities of the above species were dependent on the composition of the LC mobile phase to an astonishing degree. At concentration levels of a few hundred ng/l, laboratory experiments showed that the aromatic amines considered here were mostly associated to dissolved humic acids (HAs) by both reversible and irreversible bindings. The addition of a reducing agent, i.e., NaBH4, succeeded in liberating that fraction of aromatic amines, which being reversibly bound to quinoidal structures of HAs are bioavailable. Analyte recoveries were better than 85% on extraction from 4 l of drinking water (spike level, 25 ng/l), 2 l of ground water (spike level, 50 ng/l) and 0.5 l of river water (spike level, 200 ng/l). Relative standard deviations ranged between 4.6 and 20% for drinking water, 4.3 and 15% for ground water, 5.9 and 13% for river water. Method detection limits calculated for drinking water, groundwater and surface water were between 3 and 11, 6 and 21, 36 and 75 ng/l, respectively.

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.

[High-dose brachytherapy in endobronchial neoplastic stenoses]. / La brachiterapia con alto rateo di dose nelle stenosi neoplastiche endobronchiali.

Form March, 1991, to September, 1995, twenty-nine patients with endobronchial neoplastic stenosis were treated with high dose rate (HDR) brachytherapy at the Casa Sollievo della Sofferenza Hospital in San Giovanni Rotondo (Foggia, Italy). Fifteen patients had hemoptysis, 10 dyspnea, 6 constant cough and 6 lung atelectasis. The total dose, specified at 1 cm from the source, ranged 5 to 21 Gy and the fraction doses 5 to 15 Gy. Fourteen of 29 patients (48%) died. The mean survival is 7 months, with the follow-up ranging 1 to 22 months. Subjective responses were achieved in 78.4% of cases, with 67.6% complete and 10.8% partial remission rates. Complete remission of hemoptysis was observed in 100% of patients. Dyspnea improved in 70%, cough in 46.4% and atelectasis in 83.2%. Endoscopic findings, 1 month after the end of brachytherapy, showed a response in 79.4% of patients. The complication rate was 13.8% (1 tracheoesophageal fistula, 2 pulmonary hemorrhages and 1 cavitary necrosis). Even though the number of treated patients is small, our experience confirms the efficacy of HDR endobronchial brachytherapy in the palliation of lung cancer-related symptoms. Literature data show that brachytherapy improves the quality of life in the patients with poor prognosis who are otherwise untreatable. The HDR technique is more accurate than the LDR technique and therapy is better tolerated also because execution time is shorter. Prospective clinical trials are needed to investigate the most effective total doses and fractionations and to better define the role of brachytherapy in the curative treatment of lung cancer.

Rapid and sensitive determination of phenylurea herbicides in water in the presence of their anilines by extraction with a Carbopack cartridge followed by liquid chromatography.

A rapid and sensitive method for determining phenylurea herbicides in environmental aqueous samples in the presence of their anilines is described. The water sample is preconcentrated by passage at a flow-rate of ca. 150 ml/min through a 250-mg graphitized carbon black (Carbopack B) cartridge. After washing with 0.6 ml of methanol, the Carbopack B trap is connected with a cartridge containing a strong cation exchanger. Organics trapped by the Carbopack cartridge are eluted by passage of 6 ml of methylene chloride-methanol (95:5, v/v). Anilines and other basic compounds are quantitatively subtracted from the solvent system while flowing through the cation-exchange cartridge. After evaporation and redissolution, the sample is subjected to reversed-phase gradient elution high-performance liquid chromatography with UV detection at 250 nm. Recoveries of phenylureas added to water at levels between 30 and 3000 ng/l were higher than 92%. The limit of detection was about 1 ng/l, for a 2-1 sample. With respect to an octadecyl (C18)-bonded silica cartridge, the Carbopack B cartridge had a far better extraction efficiency for polar phenylureas.

Multiresidue method for pesticides in drinking water using a graphitized carbon black cartridge extraction and liquid chromatographic analysis.

A general liquid-solid extraction procedure for the isolation of pesticides from groundwater and drinking water for high-performance liquid chromatography (HPLC) is presented. This simple and rapid procedure involved passing a 2-L sample through a 250-mg graphitized carbon black (Carbopack B) cartridge at a flow rate of 150-160 mL/min. By taking advantage of the presence of positively charged active centers on the Carbopack B surface, a stepwise elution system allowed the complete separation of base-neutral pesticides from acidic ones. After partial solvent removal, the components in the two fractions were separated and quantified by gradient elution, reversed-phase HPLC with ultraviolet (UV) detection. The performance of the Carbopack cartridge was compared with that of a 500-mg C-18 bonded silica cartridge. With the Carbopack cartridge, the grand mean measurement accuracy of the 35 pesticides considered was 95%. With the C-18 cartridge, the grand mean measurement accuracy of the analytes was 76%. Compared to the C-18 cartridge, additional advantages of using a Carbopack cartridge are that the extraction procedure is about 7 times shorter, no pH adjustment of the environmental sample is necessary for trapping acidic compounds, and one cartridge instead of two suffices to extract base-neutral and acidic pesticides, making the Carbopack cartridge more adaptable than the C-18 one for field use. The detection limits by this method of all the pesticides considered were between 0.003 and 0.07 micrograms/L.

Antidepressants in serum determined by isolation with two on-line sorbent cartridges and liquid chromatography.

A selective method for measuring tricyclic antidepressants in serum is reported. A single assay can be done within ca. 30 min and eight samples can be assayed in less than 150 min. A 1-ml serum sample was diluted and the drugs were extracted from it by passage through a graphitized carbon black (Carbopack B) cartridge. After one washing, this cartridge was connected on line to another one containing a silica-based strong acid exchanger. The tricyclics were removed from the Carbopack surface and selectively readsorbed onto the cation-exchange surface by passing 4 ml of methylene chloride-methanol (60:40, v/v) through the two cartridges. After another wash, the drugs were desorbed from the cation-exchange surface with 0.8 ml of acetonitrile-methanol-water (72:18:10, v/v) saturated with potassium chloride. An aliquot of this solution was chromatographed on a cyano column, and the absorbance of the effluent was measured at 215 nm. The mean analytical recoveries of tricyclic antidepressants added to serum within the range 10-200 micrograms/l exceeded 90%, except for 8-hydroxyamoxapine (mean recovery 85.3%) and amoxapine (mean recovery 83.8%) at the lowest serum concentration considered.

Extraction and isolation of triazine herbicides from water and vegetables by a double trap tandem system.

The ability of a two-trap tandem system, one containing a nonspecific adsorbing material, such as graphitized carbon black (Carbopack B), and the other one filled with a sulfonic acid type silica-based cation exchanger (SCX), in extracting and isolating basic compounds from real matrices was evaluated by applying this device to the determination of triazine residues in water and vegetables. After percolation through the Carbopack column (extraction cartridge) of water samples or suitably prepared vegetable extracts, the two traps were connected in series, a methylene chloride-methanol mixture was allowed to flow along them, and triazines displaced from the extraction cartridge were selectively reabsorbed via salt formation on the strong acid exchanger column (isolation cartridge). After the column was washed, the analytes were removed from the isolation cartridge by 0.7 mL of aqueous methanol containing 70 mmol/L KCl. After the internal standard was added, the final solution was directly injected into the "high-performance" liquid chromatographic apparatus, which was operated isocratically in the reverse-phase mode with UV detection at 220 nm. The analytical recoveries of eight triazines from the two matrices considered ranged between 95% and 100%. The limits of sensitivity of this method for triazines were set at 10 ng/g of vegetable material and 10 ng/L of water by sampling 100 mL of it.

Measurement of urinary estriol glucuronides during the menstrual cycle by high-performance liquid chromatography.

A simple high-performance liquid chromatographic (HPLC) method for measuring estriol-3-glucuronide (E3-3-G) and estriol-16-glucuronide (E3-16-G) in the urine of non-pregnant women is described. Estriol conjugates were extracted from 4 ml of urine with a small cartridge of graphitized carbon black (Carbopack B). After washing, E3-3-G and E3-16-G were desorbed separately by a two-step elution system. After solvent removal, the two glucuronides were quantified by isocratic ion-suppression HPLC with fluorimetric detection. The analytical recovery of the two estriol metabolites was about 95%. The detection limit of the method was 0.6 ng/ml for both analytes in urine, which is well below the concentrations of clinical interest, and the method is not susceptible to substantial interferences. Data relative to urinary levels of E3-3-G and E3-16-G measured by this method on a daily basis in early morning samples from nine women during their menstrual cycles were compared with those reported in the literature and obtained by radioimmunoassay techniques. Moreover, the potential use of defined changes in the concentrations of the two conjugates for predicting the fertile period of women was assessed.

Rapid determination of simazine and atrazine in water at the parts per trillion (10(12) level. Extraction by a miniaturized carbopack B trap followed by high-performance liquid chromatography.

A rapid and simple method for the determination of trace amounts of simazine and atrazine in water is described. A 250-ml volume of water is pre-concentrated by passage at a flow-rate of about 30 ml/min through a small trap containing 50 mg of graphitized carbon black (Carbopack B). After washing with 150 microliters of methanol, the two herbicides are desorbed with 700 microliters of dichloromethane-methanol (60:40, v/v). After removal, of the solvent, the extracted sample is fractionated and analysed by reversed-phase high-performance liquid chromatography with UV detection at 220 nm. A single assay can be completed within 40 min from the receipt of the water sample. Recoveries of simazine and atrazine added to 250 ml of water at the level of 50 ng/l were 97.2 and 95.8% and the limits of detection were 0.07 and 0.15 ng. respectively. At the 50 ng/l level in water, the coefficients of variation for simazine and atrazine were 3.7 and 4.0% (n = 7), respectively.