Benzodiazepine derivatives are prescribed in large quantities globally and are potentially new emerging environmental contaminants. Unfortunately, a dearth of data exists concerning occurrence, persistence and fate in the environment. This paper adresses this by reviewing existing literature, assessing the occurrence of selected benzodiazepine anxiolytics (diazepam, oxazepam and bromazepam) in wastewater influent and effluent and surface water from Slovenia, evaluating their removal during water treatment and identifying the transformation products formed during water treatment. Results reveal the recalcitrant nature of benzodiazepine derivatives and suggest that only combinational treatment is sufficient to remove them. In addition, eight novel diazepam and four novel oxazepam transformation products are reported.
COBISS.SI-ID: 25246759
This article highlights the state-of-art in the analytical tools for determining environmental occurrence, fate and transformation of selective serotonin re-uptake inhibitor (SSRI) residues, and refers to the importance of combining the chemical and the effect analysis. The aim of this paper is to define the gaps in current knowledge, and in doing so, to encourage the on-going environmental analysis of SSRI. In this view, we emphasize the importance of combining advances in the instrumental analysis, novel sample preparation techniques and new approaches in toxicological analysis.
COBISS.SI-ID: 23683367
Carbamazepine, an anti-epileptic pharmaceutical agent commonly found in wastewater, is highly recalcitrant to standard wastewater treatment practices. This study investigated the mixture toxicity of carbamazepine transformation products formed during ultraviolet (UV) photolysis using three standard ecotoxicity assays (representing bacteria, algae and crustaceans). UV-treatment of 6 mg/L carbamazepine solution was carried out over a 120 min period and samples were removed periodically over the course of the experiment. Quantification results confirmed the degradation of carbamazepine throughout the treatment period, together with concurrent increases in acridine and acridone concentrations. Ecotoxicity was shown to increase in parallel with carbamazepine degradation indicating that the mixture of degradation products formed was more toxic than the parent compound. Single compound toxicity testing also confirmed the higher toxicity of measured degradation products relative to the parent compound. These results show that transformation products considerably more toxic than carbamazepine itself may be produced during UV-treatment of wastewater effluents and/or photo-induced degradation of carbamazepine in natural waters. This study highlights the need to consider mixture toxicity and the formation and persistence of toxicologically relevant transformation products when assessing the environmental risks posed by pharmaceutical compounds.
COBISS.SI-ID: 26348071
In the present study we investigate the fate of citalopram (CIT) at neutral pH using advanced water treatment technologies that include O3, ClO2 oxidation, UV irradiation and Fenton oxidation. The ozonation resulted in 80% reduction after 30 min treatment. Oxidation with ClO2 removed )90% CIT at a dosage of 0.1 mg/L. During UV irradiation 85% reduction was achieved after 5 min, while Fenton with addition of 14 mg/L (Fe2+) resulted in 90% reduction of CIT. During these treatment experiments transformation products (TPs) were formed from CIT, where five compounds were identified by using high resolution and tandem mass spectrometry. Among these desmethyl-citalopram and citalopram N oxide have been previously identified as human metabolites, while three are novel and published here for the first time. The three TPs are a hydroxylated dimethylamino-side chain derivative, a butyrolactone derivative and a defluorinated derivative of CIT.
COBISS.SI-ID: 25895975
Pharmaceuticals, which involve halogenated heterocyclic moiety, belong to various pharmacological groups. The majority act as central nervous system depressants (tranquilants or sleep inducing agents and antipsychotics). Further, widespread pharmacological groups with halogenated heterocyclic moiety are also fluoroquinolone antibiotics, thiazide diuretics, parasite and cancer chemotherapeutics, and antifungal agents. This chapter discusses the structure-activity relationship, mechanisms of action and a clinical use of pharmaceuticals involving the halogenated heterocyclic moiety.
COBISS.SI-ID: 25603879