The occurrence of selected pharmaceuticals in wastewater effluent and surface waters of the lower Tyne catchment

Endocrine disrupting chemicals (EDC) are compounds that alter the normal functioning of the endocrine system of both wildlife and humans. A huge number of chemicals have been identified as endocrine disruptors, among them several pesticides. Pesticides are used to kill unwanted organisms in crops, public areas, homes and gardens, and parasites in medicine. Human are exposed to pesticides due to their occupations or through dietary and environmental exposure (water, soil, air). For several years, there have been enquiries about the impact of environmental factors on the occurrence of human pathologies. This paper reviews the current knowledge of the potential impacts of endocrine disruptor pesticides on human health.

https://hal.archives-ouvertes.fr/hal-00878623/document

Effect of endocrine disruptor pesticides: a review.

Validation of bioanalytical LC-MS/MS assays: evaluation of matrix effects.

Matrix-dependent signal suppression or enhancement represents a major drawback in quantitative analysis with liquid chromatography coupled to atmospheric pressure ionization mass spectrometry (LC-API-MS). Because matrix effects (ME) might exert a detrimental impact on important method parameters (limit of detection, limit of quantification, linearity, accuracy, and precision), they have to be tested and evaluated during validation procedure. This review gives a detailed description on when these phenomena might be expected, and how they can be evaluated. The major sources of ME are discussed and illustrated with examples from bioanalytical, pharmaceutical, environmental, and food analysis. Because there is no universal solution for ME, the main strategies to overcome these phenomena are described in detail. Special emphasis is devoted to the sample-preparation procedures as well as to the recent improvements on chromatographic and mass spectrometric conditions. An overview of the main calibration techniques to compensate for ME is also presented. All these solutions can be used alone or in combination to retrieve the performance of the LC-MS for a particular matrix-analyte combination.

An overview of matrix effects in liquid chromatography-mass spectrometry.

Analytical strategies for residue analysis of veterinary drugs and growth-promoting agents in food-producing animals - A review

The ion suppression phenomenon in liquid chromatography–mass spectrometry and its consequences in the field of residue analysis

Residues of the tetracycline group of antibiotics were quantified in pork and chicken muscle tissue that had previously been screened with a microbiological inhibition test and an immunological method. Pieces of frozen pork and chicken meat were screened on a pH 6 culture medium seeded with Bacillus subtilis. An aqueous extract of the inhibitor-positive samples was then screened with a group-specific commercial ELISA kit, able to detect levels of oxytetracycline, chlortetracycline, tetracycline and doxycycline corresponding with the European MRL or lower. The cut-off value of the ELISA was set at a B/B0 value of 75%. Finally, confirmation and quantification were performed using a validated HPLC method with fluorescence detection. The fluorescence was induced by complexation of the tetracyclines with the zirconium cation which is added post-column to the HPLC eluate. This fluorescence makes it possible to quantitate residues below one-half of the MRL. To gain additional qualitative information some samples were also analysed with LC-MS-MS.ELISA analysis demonstrated the presence of residues of tetracyclines in 12 out of 19 inhibitor-positive pork samples and in 19 out of 21 inhibitor-positive chicken samples. Doxycycline was detected with HPLC in 10 of these 12 pork samples and in 18 out of 19 chicken samples. The two other ELISA positive pork samples contained oxytetracycline, while no tetracyclines were found in one ELISA positive chicken meat sample. The correlation between the ELISA B/B0 values and the actual levels determined with the HPLC method was poor, whereas a better correlation was observed between the inhibition zones and the doxycycline levels. Our results indicate that an inhibition test with a medium at pH 6 and B. subtilis as test organism is well suited to screen pork and chicken muscle tissue for residues of tetracycline antibiotics. Since many positive samples contained doxycycline levels below the MRL, a confirmatory method is necessary to quantify the residues.

http://lib3.dss.go.th/fulltext/Journal/analyst/Analyst1998/no.12/12,1998vol123p2737-2741.pdf

Detection of residues of tetracycline antibiotics in pork and chicken meat: Correlation between results of screening and confirmatory tests.

Screening and confirmation of chloramphenicol in shrimp tissue using ELISA in combination with GC–MS2 and LC–MS2

Screening and confirmation of chloramphenicol in shrimp tissue using ELISA in combination with

The use of identification points (IPs) is a new approach to set up quality criteria for the identification of organic residues and contaminants: a laboratory is allowed to use any molecular spectrometric technique or combination of techniques in order to earn a minimum number of points. The system of IPs balances the identification power of the different analytical techniques and has the advantage that new techniques can be introduced very easily. © 2001 Elsevier Science B.V. All rights reserved.

Katia De Wasch

Papers

The ion suppression phenomenon in liquid chromatography–mass spectrometry and its consequences in the field of residue analysis

Detection of residues of tetracycline antibiotics in pork and chicken meat: Correlation between results of screening and confirmatory tests.

Screening and confirmation of chloramphenicol in shrimp tissue using ELISA in combination with GC–MS2 and LC–MS2

Screening and confirmation of chloramphenicol in shrimp tissue using ELISA in combination with

Trends in the identification of organic residues and contaminants: EC regulations under revision