The occurrence of pharmaceuticals in the aquatic environment has become a matter of concern in the last decade due to potential risks posed to non-target organisms and the potential for unintended human exposure via food chain. This concern has been driven by a high detection frequency for drugs in environmental samples; these substances are produced in large quantities and are used in both veterinary and human medicine, leading to deposition and potential effects in the environment. However, few studies have focused on the presence of pharmaceuticals in rural areas associated with farming activities in comparison to urban areas. The aim of this study is to investigate the occurrence of pharmaceutically active compounds in surface waters collected from urban and rural areas in northwestern Spain. A monitoring study was conducted with 312 river water samples analysed by high-performance liquid chromatography coupled to tandem mass spectrometry. Positive detection of pharmaceuticals was made for 51 % of the samples. Decoquinate, sulfamethazine, sulfamethoxypyridazine and trimethoprim were the drugs most frequently detected, being present in more than 10 % of the samples. The sampling sites located downstream of the discharge points for wastewater treatment plants yielded the highest number of positive samples, 13 % of the positive samples were detected in these sites and 38 % of the samples collected near the collection point of a drinking water treatment plant were positive.

The agar dilution method was used to determine the activities of gentamicin, erythromycin, streptomycin, chloramphenicol, ampicillin, sulfamethazine, cephalothin, penicillin G, and tetracycline against 73 strains belonging to the genus Listeria (L. innocua, L. seeligeri, and L. monocytogenes). All strains were isolated from raw milk, cheese, the dairy processing plant, poultry, and the poultry slaughterhouse. Gentamicin, ampicillin, and erythromycin, of which the MICs for 90% of the strains tested for all three species were .5.96 ,ug/ml, were found to be the most active agents studied. Most of the L. innocua strains isolated from poultry and the poultry slaughterhouse were resistant to tetracycline.Listeriosis is an infectious disease which affects both humans and animals. Most cases of human listeriosis appear to be sporadic, although a portion of these sporadic cases may be previously unrecognized common-source clusters (4). The source and route of infection are usually unknown. However, the recent ass §iciation of Listenia monocytogenes with several large food-borne outbreaks (8,11) suggests that contaminated food may be the primary source of the organism.Penicillin or ampicillin, alone or in combination with an aminoglycoside, seems to be the drug of choice (5); a trimethoprim-sulfamethoxazole combination has also been used (13). Although most clinical isolates of L. monocytogenes are susceptible in vitro to penicillin, ampicillin, tetracycline, and other antimicrobial agents, few quantitative studies have been carried out to determine the in vitro susceptibilities of Listeria spp. isolated from food. The purpose of the present study was to determine the susceptibilities of 73 strains of the genus Listeria, all isolated from food and food-processing plant environments, to nine antimicrobial agents: gentamicin, erythromycin, streptomycin, chloramphenicol, ampicillin, penicillin G, cephalothin, sodium sulfamethazine, and tetracycline.The study was carried out with 73 strains belonging to the genus Listeria. The strains were isolated by us from raw milk and cheese obtained from several markets, the environment from one dairy plant, the environment from one poultry slaughterhouse, and poultry from the same slaughterhouse. Numbers of strains of each Listeria species for each source and dates of isolation are shown in Listeria strains isolated from raw milk, cheese, the dairy plant, poultry, and the poultry slaughterhouse are shown in Table 2.The concentrations of gentamicin to which the Listeria innocua and Listeria seeligeri strains isolated in this study were susceptible ranged from 0.74 to 2.98 jig/ml. Results similar to those obtained in the present study have been reported for L. monocytogenes (3,10

Drug residues are considered environmental contaminants, and their occurrence has recently become a matter of concern. Analytical methods and monitoring systems are therefore required to control the continuous input of these drug residues into the environment. This article presents a suitable HPLC-ESI-MS/MS method for the simultaneous extraction, detection and quantification of residues of 13 drugs (antimicrobials, glucocorticosteroids, anti-inflammatories, anti-hypertensives, anti-cancer drugs and triphenylmethane dyes) in surface water. A monitoring study with 549 water samples was carried out in northwestern Spain to detect the presence of drug residues over two sampling periods during 2010, 2011 and 2012. Samples were collected from rural areas with and without farming activity and from urban areas. The 13 analytes were detected, and 18% of the samples collected showed positive results for the presence of at least one analyte. More collection sites were located in rural areas than in urban areas. However, more positive samples with higher concentrations and a larger number of analytes were detected in samples collected from sites located after the discharge of a WWTP. Results indicated that the WWTPs seems to act as a concentration point. Positive samples were also detected at a site located near a drinking water treatment plant.

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The comparison of SPME fiber coatings, and optimization of temperature and time of extraction for headspace solid phase microextraction (HS-SPME) of volatile organic compounds (VOCs) present in Pouteria sapota (sapote mamey) fruits is presented. The PDMS/DVB coating afforded the highest extraction efficiency. The extraction conditions were optimized by using Doehlert experimental design. By using the optimized HS-SPME method, 21 VOCs were identified, which include mainly terpenoids and esters, followed by aromatic hydrocarbons, aldehydes, alcohols and ketones. The most abundant compounds in Pouteria sapota pulp were cedrol (25.0%), azulene (7.3%), β-ionone (5.7%) naphthalene (5.6%), α-pinene (5.0%), and benzaldehyde (4.3%). Seventeen VOCs were identified for the first time in the fruit.