Neuropeptidomics, a mass spectrometry-based technique which aims to uncover the complete suite of neuropeptides present in a tissue, organ or cell from the brain or nervous system, has found application in studies examining physiological responses (e.g. food intake, appetite and reproduction). Neuropeptides (and peptide hormones) have long been known as regulators of mammalian physiological processes, particularly reproduction. These peptides are derived from precursor proteins and become active via proteolytic processes and post-translational modifications. A relatively large number of neuropeptides, mainly formed in the hypothalamus or the anterior pituitary of mammals, have been specifically associated with reproduction, including GnRH, NPY, PYY and kisspeptin. Here, we will present an overview of neuropeptides, their roles in reproduction and the application of neuropeptidomics in this field. We address the advantages of neuropeptidomics in reproductive studies including the high throughput identification, profiling and quantification of neuropeptides present in reproductive tissues and also discuss some of the challenges. The application of neuropeptidomics to the field of reproduction will provide the foundation for a greater understanding of how neuropeptides act to regulate reproductive function.
In the present study, we propose a method for the evaluation of different classes of xenobiotic organic compounds enclosed in the municipal landfill leachate using comprehensive two-dimensional gas chromatography coupled with quadrupole mass spectrometry (GCxGC-qMS). Here we show that, due to high peak capacity of comprehensive two-dimensional gas chromatography, in a single run it is possible to separate compounds with different physical-chemical properties (such as aliphatic and aromatic compounds, polyaromatic hydrocarbons, phenols, phthalates, aldehydes, ketones, nitrogen containing compounds, organo-phosphoric flame retardants etc.), compounds which have proved to be endocrine disruptors, compounds that are persistent, bioaccumulative and toxic, carcinogenic, mutagenic, teratogenic, reprotoxic or harmful for the environment. Even though a solvent extraction method has been optimised, the extraction step still remains the main problem for a comprehensive characterization of all classes of organic toxicants enclosed in the municipal landfill leachate. [...]
The present review shows the utility of using mass spectrometry (MS) in obstetrics and gynecology. In this review different gas chromatography / mass spectrometry and liquid chromatography / mass spectrometry methods developed before to be used in obstetrics and gynecology are described. These methods are very useful to determine different hormones in pregnancy, fatty acids esters (related to the use of ethanol) in human meconium and toxic compounds in umbilical cord (as ethanol, steroids, morphine, cocaine, methadone and other drugs). It is also shown in this review the progress during last decades in the field of using mass spectrometry in obstetrics and gynecology (for screening in utero exposure of the child to alcohol, drugs and other toxic compounds). In the field of using mass spectrometry in obstetrics and gynecology are still many problems to solve. For example, the detection of fatty acids esters in meconium has several limitations, which affects the results. One limitation is multiple births. Also in fetal distress, meconium may be passed before birth, and in this case, the collection is impossible. Moreover the meconium is formed starting from the fourth month of pregnancy, so the fetal exposure at any toxic compounds during the first three months cannot be detected at all. To solve all of these, the best would be to combine the results obtained from meconium, with other results obtained from pregnancy serum, placenta or umbilical cord. The main reason for using MS in obstetrics and gynecology is that MS is a noninvasive and a complementary method. It offers the results at a very early point in time, even before the act of birth. Sometimes the use of mass spectrometry is the only alternative. This shows that these methods are of great interest for the future and need to be developed further. [...]
This study is focused on the determination of some important antibiotics from different classes in waste water samples using solid phase extraction followed by high performance liquid chromatography with two detectors, diode array and mass spectrometer in positive ionisation mode. The investigated antibiotics include three penicillins (amoxicillin, ampicillin, penicillin G), two cephalosporins (ceftazidime, ceftriaxone), and two tetracyclines (tetracycline, doxycycline). The studied antibiotics were extracted from waste water samples using hydrophilic-lipophilic balanced cartridges. The extraction of antibiotics from water matrices was tested at several pH values. The best recoveries were obtained at pH 3 and 7 respectively. Depending on the nature of antibiotic, the limits of detection and quantification were obtained in the range of 0.07–0.92 µg mL−1 and 0.21–2.77 µg mL−1 respectively. Influent and effluent waste water samples were collected from a Waste Water Treatment Plant from Romania in order to detect the studied antibiotics. The antibiotics detected in the influent waste water samples were ceftriaxone (334 µg L−1), tetracycline (146 µg L−1) and doxycycline (110 µg L−1). In effluent waste water samples no target antibiotics were detected. [...]
One of the quantification methods frequently applied to pesticide residue analysis in food by liquid chromatography - mass spectrometry (LC-MS) involves matrix-matched calibrations with a representative matrix used for all commodities belonging to one group. This approach, although very practical, is deemed to generate analytical errors. The effect of the application of a representative-matrix calibration curve on the pesticide quantification result was examined. Extractions of 56 pesticides from five soft fruits (strawberries, blackberries, raspberries, black currant and red currant) were carried out using QuEChERS method. Pesticide determinations were performed by LC-MS/MS in multiple reaction monitoring mode. Quantification difference functions and parameters were proposed and calculated. At the concentration of 0.05 mg kg−1 for ca. 90% of examined pesticides the quantification difference arising from the use of a representative matrix calibration curve (raspberries) instead of a specific fruit matrix calibration curve was below 20% for black and red currents, and below 30% and 35% in the case of strawberries and blackberries, respectively. The 25% difference limit was not exceeded for 51 pesticides in black and red currents, 46 pesticides in blackberries and 45 pesticides in strawberries. Quantification difference functions and parameters such as relative standard deviation of corrected process efficiencies were found to be helpful in data-driven decision-making on the applicability of a representative matrix; the former may be also used as a tool for data correction to ensure the reliability and accuracy of analyses. [...]
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