Carbamazepine is an antiepileptic drug which is considered one of the persistent compounds detected in Malaysian aquatic environment. In this present study, a full factorial experimental design was applied for the analysis of effect NaCl amount, initial concentration of carbamazepine, applied voltage and treatment time on the electrochemical removal percentage of carbamazepine. However, applied voltage was found as the most significant factor with p = 0.00 lower than 95% confidence level. The investigation of effect NaCl and Na2SO4 on the pathway degradation for carbamazepine was provided using liquid chromatography-time of flight/mass spectrometry (LC-TOF/MS). The results showed that new by-products were identified such chloro-epoxy carbamazepine, and other by-products, were detected in the presence of NaCl and Na2SO4 electrolytes. High inhibition percentage of Escherichia coli (E. coli) bacteria was observed at 24.0 h incubation time for both NaCl and Na2SO4 electrolytes after 80 and 20 min of treatment, respectively.

The present work reports the occurrence and monitoring of 11 pharmaceuticals (i.e., caffeine, prazosin, enalapril, carbamazepine, nifedipine, gliclazide, levonorgestrel, simvastatin, hydrochlorothiazide, diclofenac-Na and mefenamic acid) in surface water and in the influent and effluent of sewage treatment plants (STPs) and hospitals (HSPs). A total of 105 water samples were analyzed using solid-phase extraction combined with liquid chromatography-time-of-flight/mass spectrometry (SPE-LC-TOF/MS). The mean concentrations of the detected pharmaceuticals in STP influent and effluent ranged from < limit of quantification (LOQ) to 3909 ng L−1 and 12 to 577 ng L−1, respectively. The mean concentrations of the detected pharmaceuticals in the hospital influent and effluent ranged from 28 to 1644 ng L−1 and 20 to 1540 ng L−1, respectively. The highest concentration detected in the sampling points was 9099 ng L−1 for caffeine in influent STP. The presence of prazosin has never been reported before in literature. In this study, prazosin was detected in all studied samples, and the highest concentration was 525 ng L−1 in influent STP. Chemometric analysis was used to assess the presence of pharmaceuticals in samples.

The preparation of a new carbon composite electrode constructed from graphite-polyvinyl chloride (graphite-PVC) compressed mixtures was used for the first time to treat landfill leachate in Malaysia under electrochemical oxidation. The electrochemical oxidation of landfill leachate was studied on graphite-PVC and Pt electrodes as anode and cathode, respectively, with the presence of NaCl electrolyte in a batch electrochemical reactor. The highest chemical oxygen demand (COD) and color removals of 87% and 97%, respectively, were achieved at pH 3, 0.58% (m/v) + 2078 mg L-1 electrolyte concentration, 15 V applied voltage, and 105 min electrolysis time. To confirm electrochemical oxidation, a field emission scanning electron microscopy (FESEM) was used to evaluate the surface of graphite-PVC electrode before and after treatment. The constant rate in terms of pseudo-first-order kinetics increased from 0.0015 min-1 to 0.0186 min-1 at 5 and 20 V applied voltage. The graphite-PVC composite exhibits favorable qualities as an electrode material because of its mechanical resistance, low cost, simple preparation, and easy renewal of the electrode surface.

Fármacos são substâncias químicas sintéticas ou naturais que podem ser encontrados em medicamentos de prescrição médica, drogas terapêuticas isentas de prescrição e medicamentos veterinários. A ocorrência de fármacos no meio ambiente e no ciclo da água em quantidades vestigiais (na faixa de nanogramas a poucos microgramas por litro) tem sido amplamente discutida na literatura na década passada. O aumento na frequência de detecção é em grande parte atribuída aos avanços nas técnicas analíticas e instrumentação. Este artigo descreve o desenvolvimento, otimização e validação de um método de análise simultânea de sete produtos farmacêuticos de diferentes classes cafeína (CAF), prazosina (PRZ), maleato de enalapril (ENL), carbamazepina (CBZ), nifedipina (NFD), levonorgestre l (GNL), sinvastatina (SMV) utilizando extração em fase sólida (SPE cartuchos Oasis HLB ) seguido por cromatografia líquida acoplada a espectrometria de massas com tempo de voo e ionização por electrospray (LC-ESI-TOF/MS). A faixa linear de calibração, 0,5-250 µg L-1, proporcionou coeficientes de correlação linear (R2) acima de 0,99 para todos os compostos. Os limites de quantificação instrumental (IQL) para todos os produtos farmacêuticos variou de 0,5-5 µg L-1 no solvente por injeção direta de uma mistura padrão. A eficiência de extração (EE%), para a maioria dos compostos, foi superior a 40 e 60%, em água de rio e em água pura, respectivamente. O limite de quantificação (LOQ) para todos os produtos farmacêuticos variou de 13-800 ng L-1 para água de rio. A precisão inter e intra dia do método foi calculado, como o desvio-padrão relativo (RSD%) de 2,33-22,3% e 0,6-9,9% , respectivamente, exce to para a cafeína, que apresentou um RSD% de 20,1% a 50 µg L-1. O efeito da matriz variou entre 10-41%. Dos sete produtos farmacêuticos, seis compostos farmacêuticos foram detectados na amostra de água de rio.

Pharmaceuticals are synthetic or natural chemicals that can be found in prescription medicines, over-the-counter therapeutic drugs and veterinary drugs. The occurrence of pharmaceuticals in the environment and the water cycle at trace levels (in the range of nanograms to low micrograms per litre) has been widely discussed and published in literature in the past decade. The increase in detection is largely attributable to the advances in analytical techniques and instrumentation. This paper describes development, optimisation and validation of a method for the simultaneous analysis of 7 multi-class pharmaceuticals (caffeine (CAF), Prazosin (PRZ), enalapril maleate (ENL), carbamazepine (CBZ), nifedipine (NFD), levonorgestrel (LNG), simvastatin (SMV)) using solid phase extraction (SPE cartridges Oasis HLB) followed by liquid chromatography-time-of-flight/mass spectrometry (LC-ESI-TOF/MS). Its linearity, 0.5-250 µg L-1, provided determination coefficients (R²) above 0.99 for all compounds. The Instrumental Quantification Limits (IQLs) for all pharmaceuticals ranged from 0.5-5 µg L-1 in the solvent as a standard mixture (i.e., direct injection). The extraction efficiency (EE%) was more than 40% and 60% in river and deionised water for most of compounds, respectively. Limit of quantification (LOQ) for all pharmaceutic als ranged from 13-800 ng L-1 in spiked river water. The inter and intra day precision of the method, calculated as the relative standard deviation (RSD%), 2.33-22.3% and 0.6-9.9%, respectively, except for caffeine, which has a RSD% of 20.1% at 50 µg L-1. Matrix effect was investigated and ranged from 10-41%. Out of seven pharmaceuticals, six pharmaceutical compounds were detected in the river water sample.