Presence of therapeutic drugs in the environment.

Therapeutic drugs can contaminate the environment because of metabolic excretion, improper disposal, or industrial waste. To assess the extent of this contamination, we listed drugs thought to be putative priority pollutants according to selected criteria, and measured them in Lombardy, Italy. Most drugs were measurable in drinking or river waters and sediments, suggesting that pharmaceutical products are widespread contaminants, with possible implications for human health and the environment.

Analysis of benzothiazole in Italian wines using headspace solid-phase microextraction and gas chromatography-mass spectrometry.

Benzothiazoles are a part of the molecular structure of a large number of natural products, biocides, drugs, food flavors, and industrial chemicals. They also appear in the environment mainly as a result of their production and use as rubber vulcanization accelerators. A new headspace solid-phase microextraction (HS-SPME) method for analysis of benzothiazole (BTH) in wine is described. This method is fast, inexpensive, and does not require solvents. The detection limit of BTH in wine was 45 ppt with linearity up to 100 ppb. The quantification of BTH is performed by the standard additions method and does not require the use of an internal standard. We have analyzed 12 wines from different grape varieties grown in several regions, using SPME extraction and gas chromatography-mass spectrometry (GC-MS) detection. Under these experimental conditions, benzothiazole was found in all wines analyzed. Concentration levels in samples varied from 0.24 microg/L (Vermentino) to 1.09 microg/L (Franciacorta).

Analysis of some pesticides in water samples using solid-phase microextraction-gas chromatography with different mass spectrometric techniques.

A solid-phase microextraction (SPME)-GC procedure has been developed for the analysis of four selected pesticides (propanil, acetochlor, myclobutanil and fenoxycarb) in water samples. Mass spectrometry (MS) was used and two different instruments, a quadrupole MS system and an ion trap operating in the MS-MS mode, were compared. A Carbowax-divinylbenzene SPME fiber was used. The performances of the two GC-MS instruments were comparable in terms of linearity (in the range of 0.1-10 microg/l in water samples) and sensitivity (limits of detection were in the low ng/l range); the quadrupole MS instrument gave better precision than the ion trap MS-MS system, but generally the relative standard deviations for replicates were acceptable for both instruments (<15%). Specificity with these two instruments was comparable in the analysis of ground water samples. Recovery tests were made to assess the applicability of the SPME procedure in the quantitative analysis of contaminated groundwaters.

Deuterated internal standards for gas chromatographic-mass spectrometric analysis of polar organophosphorus pesticides in water samples.

It is essential to know whether drinking water contains any pesticides up to concentrations close to the European Union limit of 0.1 microgram/l, in order to protect the population. Mass spectrometry (MS) using a suitable internal standard (I.S.) should improve the quantitative analysis of pesticides, the I.S. circumventing loss of compounds during the analytical procedure and correcting the analytical variability. In this study we verified this assumption in GC-MS, synthesising specific internal standards for four organophosphorus pesticides with poor stability, comparing the performances with and without the I.S.

Specific gas chromatography-mass spectrometry analytical method for the determination of cyhexatin in animal feed.

The acaricide tricyclohexyltin hydroxide (cyhexatin) was determined in animal feed samples, using gas chromatographic--mass spectrometry in the electron impact mode. Sample extraction and derivatization (converting the analyte to an alkylated derivative) were performed using a tricyclopentyl analogue of this acaricide as internal standard to obtain a better analytical precision.

Migration of vinyl chloride into PVC-bottled drinking-water assessed by gas chromatography-mass spectrometry.

The migration of vinyl chloride (VC) into drinking-water bottled in polyvinyl chloride (PVC) was studied in relation to storage time, using a gas chromatographic-mass spectrometric method. Trideuterated vinyl chloride was used as internal standard. VC concentrations in the water rose progressively in direct (linear) relation to the time after bottling (about 1 ng/litre/day). The time of storage of PVC-packaged foodstuffs may affect the daily oral intake of this monomer, which in some cases may exceed 100 ng/person/day.