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1.
Environ Sci Pollut Res Int ; 31(21): 31201-31212, 2024 May.
Article in English | MEDLINE | ID: mdl-38625467

ABSTRACT

Benzophenone-4 (BP-4) is one of the UV filters widely used in personal care products (PCPs). BP-4 has been identified as an emergent contaminant detected in influent and effluent of wastewater treatment plants (WWTPs) at high concentrations showing that conventional treatment is unable to remove it, subsequently, the presence of BP-4 in surface water is inevitable. In this study, we focus on the degradation of this compound by chlorine, and we report the efficiency of its removal from water by applying two advanced oxidation processes UV/TiO2 and UV/H2O2 aiming to achieve a superior mineralization result. The study was performed in purified water (pH = 6.5, temperature = 25 °C) with an initial concentration of BP-4 similar to that detected in WWTPs (10 mg/L). The results showed that 76% of BP-4 was degraded after 80 min of reaction with chlorine leading to the formation of one by-product persistent in the solution. The oxidation by UV/TiO2 and UV/H2O2 led to a total removal of BP-4 and their generated by-products after 50 and 10 min of reactions, respectively. The kinetic study showed that BP-4 degradation by UV/H2O2 and UV/TiO2 followed pseudo-first-order reaction kinetics and the apparent rate constants (kapp) were determined to be 0.48 min-1 and 0.08 min-1, respectively. The degradation of BP-4 by chlorine followed first-order reaction kinetics with kapp = 0.02 min-1. The identification of by-product structures was performed using liquid chromatography with electrospray ionization and tandem mass spectrometry (MS/MS. The fragmentation of BP-4 and by-product ions at different collision energies allowed to propose the pathways of degradation and to predict the toxicity using a silico toxicity program which confirmed a higher toxicity of all generated by-products.


Subject(s)
Benzophenones , Halogenation , Oxidation-Reduction , Water Pollutants, Chemical , Kinetics , Benzophenones/chemistry , Water Pollutants, Chemical/chemistry , Water Purification/methods , Wastewater/chemistry , Titanium/chemistry , Hydrogen Peroxide/chemistry
2.
Food Addit Contam Part B Surveill ; 17(1): 87-99, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38235577

ABSTRACT

Antimicrobials are administered in livestock for different uses leading to milk contamination and several undesirable effects. Because there is a lack of surveillance of antimicrobial residues (AMRs) in milk and dairy products in Lebanon, this study aims to determine the occurrence of AMRs in 90 Lebanese samples of milk and labneh (concentrated yoghurt). Multi-residue screening methods with suitable sample preparations were applied to detect 71 AMRs in milk and labneh, respectively, using LC-MS/MS. Of the total number of samples, 71% was contaminated with AMRs and (fluoro)quinolones and macrolides were the most detected families. Additional confirmation tests proved that 6.7% of the milk samples were non-compliant for the macrolides tilmicosin, tulathromycin and spiramycin. Moreover, some labneh prepared from contaminated milk samples was analysed to determine the fate of AMRs during the manufacturing process. The results showed that some AMRs could be concentrated, eliminated or degraded, based on their physicochemical characteristics.


Subject(s)
Anti-Infective Agents , Drug Residues , Humans , Animals , Chromatography, Liquid , Milk/chemistry , Lebanon , Tandem Mass Spectrometry , Food Contamination/analysis , Anti-Infective Agents/analysis , Anti-Bacterial Agents/analysis , Macrolides/analysis , Drug Residues/analysis
3.
BJS Open ; 7(5)2023 09 05.
Article in English | MEDLINE | ID: mdl-37882628

ABSTRACT

BACKGROUND/AIMS: Crohn's disease is an inflammatory bowel disease with up to 50 per cent of patients requiring surgery within 10 years of diagnosis. Patient-reported outcome measures (PROMs) are vital to monitor and assess patient health-related quality of life (HRQoL). This systematic review aims to evaluate PROMs within studies for perioperative Crohn's disease patients. METHODS: Articles from MEDLINE, Embase, Emcare and CINAHL databases were searched to find studies relating to the assessment of HRQoL in perioperative Crohn's disease patients using PROMs and patient-reported experience measures (PREMs) from 1st January 2015 to 22nd October 2023. Bias was assessed using the ROBINS-I tool was used for non-randomized interventional studies and the Cochrane RoB2 tool was used for randomized trials. RESULTS: 1714 journal articles were filtered down to eight studies. Six studies focused on ileocaecal resection, one on perianal fistulas and one on the effects of cholecystectomy on patients with Crohn's disease. Within these articles, ten different PROM tools were identified (8 measures of HRQoL and 2 measures of functional outcome). Overall improvements in patient HRQoL pre- to postoperative for ileocaecal Crohn's disease were found in both paediatric and adult patients. Outcomes were comparable in patients in remission, with or without stoma, but were worse in patients with a stoma and active disease. CONCLUSION: There are significant variations in how PROMs are used to evaluate perioperative Crohn's disease outcomes and a need for consensus on how tools are used. Routine assessments using an internationally accepted online platform can be used to monitor patients and support areas of treatment pathways that require further support to ensure high standards of care. They also enable future statistical comparisons in quantitative reviews and meta-analyses.


Subject(s)
Crohn Disease , Adult , Humans , Child , Crohn Disease/surgery , Quality of Life , Cholecystectomy , Consensus , Patient Reported Outcome Measures
4.
Environ Sci Pollut Res Int ; 30(53): 114239-114248, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37858018

ABSTRACT

Ultrasound as a green and efficient process gains special attention in wastewater treatment. The ultrasound-assisted degradation of azoxystrobin, methoxyfenozide, and propyzamide as widely used pesticides for vine treatment was investigated. A wide range of ultrasonic power (40 to 140 W) and a single frequency (20 kHz) were applied. Degradation experiments were carried out according to the parameters set by a central composite design (CCD) under response surface methodology (RSM) via JMP software. The treatment efficiency was quantified using degradation rates and hydrogen peroxide (H2O2) measurements. Results indicated that the pesticide's degradation was negligible at 40 W but by increasing the power setting from 80 to 140 W, the degradation rate constants of azoxystrobin, methoxyfenozide, and propyzamide increased from 3.6 × 10-2 min-1 to 0.2 min-1, from 6.1 × 10-2 min-1 to 0.3 min-1, and from 3.1 × 10-2 min-1 to 0.1 min-1, respectively. The hydrogen peroxide (H2O2) measurements confirmed this trend. Besides, electric energy per order of pollutant removal (EE/O) was also evaluated for the same treatment duration and results revealed that treatment conditions of 20 kHz and 140 W were the less energy-guzzling. Finally, profiles obtained with RSM illustrated linear degradation kinetics for azoxystrobin and propyzamide. Indeed, treatment efficiency increased when increasing both studied parameters. However, both linear and quadratic degradation kinetics occurred for methoxyfenozide degradation indicating a parameter threshold beyond which the trend is reversed. Overall, this study confirms the effectiveness of ultrasound for the degradation of pesticides in aqueous medium.


Subject(s)
Hydrogen Peroxide , Pesticides
5.
Biol Trace Elem Res ; 200(11): 4608-4614, 2022 Nov.
Article in English | MEDLINE | ID: mdl-35048269

ABSTRACT

To explore the correlation of AL-based food consumption, known to have negative impact on health, and Al plasma levels with pregnancy status. A cross-sectional study was conducted on 75 participants, including 50 pregnant women. Al plasma levels were analyzed by ET-AAS. Exposure to food was positively correlated to Al mean plasma levels (reaching 2.12 ± 1.17 µg/L) by 32%, specifically for potatoes, fruits, soft drinks, and ready meals. Usage of Al cookware was associated to higher Al plasma levels while pregnancy status was protective. Establishment of national recommendation to maintain lower levels of Al in food is required.


Subject(s)
Aluminum , Pregnant Women , Cross-Sectional Studies , Female , Humans , Pregnancy
6.
Environ Sci Pollut Res Int ; 29(13): 18605-18616, 2022 Mar.
Article in English | MEDLINE | ID: mdl-34697706

ABSTRACT

This paper describes an analytical approach based on solid-phase extraction (SPE) followed by analysis using liquid and gas chromatography coupled to mass spectrometry detectors for a determination of 18 organic UV filters from water samples. Extraction method parameters were optimized: 250 ml of water sample loaded on Chromabond C18 cartridges after adjustment to pH 4 and then eluted with acetonitrile. The mobile phase and the parameters of the mass spectrometer, as well as those of the ionization source, were tested to enhance detection sensitivity. During method validation, the extracted target compounds showed good recoveries (> 68%) with acceptable values in terms of repeatability (RSDr) and reproducibility (RSDR), where relative standard deviations values were lower than 20%. The validated method was applied to 10 water samples collected from different swimming pools located in Lebanon from which eight UV filters among the eighteen targets compounds were detected at concentrations ranged between 1 and 2526 µg L-1. The most detected compounds were padimate-O (OD-PABA) and octocrylene (OCR). This study represents the first available data on the occurrence of UV filter residues in Lebanese swimming pool opening hence future perspectives and insights to evaluate their degradation by-products and their toxicity on human health and marine ecosystem.


Subject(s)
Swimming Pools , Tandem Mass Spectrometry , Chromatography, High Pressure Liquid , Ecosystem , Gas Chromatography-Mass Spectrometry , Humans , Reproducibility of Results , Tandem Mass Spectrometry/methods , Water
7.
Burns ; 47(6): 1241-1251, 2021 09.
Article in English | MEDLINE | ID: mdl-33980400

ABSTRACT

BACKGROUND: Major burns complicated by stress ulceration and perforation of the stomach or duodenum is a recognized clinical phenomenon. Colonic perforation in burns patients is not common, and the overall incidence, diagnosis, intervention undertaken and mortality is incompletely described in the literature. METHOD: We performed a systematic review of the literature on severe burns resulting in colonic perforation during the initial admission period. Relevant studies from January 1975 to June 2020 were retrieved from MEDLINE and EMBASE databases. Patient demographics, co-morbidities, total body surface area (TBSA) and anatomical region of burn, site of colonic perforation and management, nutrition, sepsis and microbiology, length of stay and overall outcome were extracted. We present a case series of five burns patients who had colonic perforations in our Specialist Burns Center. RESULTS: We identified 54 studies, of which nine (two case series and seven case reports) met the inclusion criteria. Colonic perforation following burns was most common in middle-aged male patients with a proportion of patients having a history of mental health issues. In most cases, the TBSA associated with a colonic perforation was ≥30% (11/16 patients, 69%). Perforations mainly affected the right side of the colon (12/16 patients, 75%), usually occurring after the second week of admission (13/16 patients, 81%). Right-sided colonic perforations were associated with an increased mortality rate compared to left-sided perforations (42% vs 25%). CONCLUSIONS: The current literature is mainly limited to case series and case reports and confirms that colonic perforations in burns patients are rare. Colonic perforations are related to the systemic effect of burn injuries including sepsis and gastrointestinal stasis. We have identified patients who are at higher risk of developing colonic perforations and have described the common findings in these patients. Through greater awareness early diagnosis and prompt intervention may be achieved to improve outcomes and reduce associated morbidity and mortality.


Subject(s)
Burns , Colonic Diseases , Intestinal Perforation , Sepsis , Body Surface Area , Burns/epidemiology , Colonic Diseases/epidemiology , Humans , Intestinal Perforation/epidemiology , Male , Middle Aged , Retrospective Studies
8.
J Mass Spectrom ; 56(6): e4730, 2021 Apr 15.
Article in English | MEDLINE | ID: mdl-34000760

ABSTRACT

Honey is one of the most valuable sweeteners consumed by humans all over the world. Consequently, it is often a target for adulteration through the addition of different sugar syrups during or after honey production, resulting in a reduction in its nutritive value. For the first time, this study analyzes honey samples of various botanical species collected from different Lebanese regions using element analyzer (EA) and liquid chromatography (LC) coupled with isotope ratio mass spectrometry (IRMS). The δ13 C of bulk honey, its protein fraction, and the main individual sugars (glucose, fructose, disaccharides, and trisaccharide) were determined, in order to characterize and evaluate the authenticity of honey consumed in Lebanon. The results showed that the δ13 C values for bulk honey and its protein range from -26.5‰ to -24.5‰ and from -26.4‰ to -24.7‰, respectively, for authentic samples. δ13 C values for samples adulterated with sugar syrups range from -11.2‰ to -25.1‰ for bulk honey and from -26.6‰ to -23.7‰ for its proteins, with a difference between bulk and protein values between -1 and -8.7‰. Using LC-C-IRMS techniques, the δ13 C of individual sugars provides additional information on the presence of undeclared sugars. We found that all authentic samples had Δδ13 Cf-g and Δδ13 C max values within the naturally occurring range of ±1‰ and ±2.1‰, respectively, while the adulterated samples fall outside the Δδ13 C ranges. The oligosaccharide peak was detected in most adulterated samples.

9.
F1000Res ; 9: 1254, 2020.
Article in English | MEDLINE | ID: mdl-33299557

ABSTRACT

Background: The expanding burden of diet-related non-communicable diseases in the Eastern Mediterranean Countries requires urgent public health vigilance and actions. This study aimed at establishing a database analysis of total sugar, salt and iron content in Lebanese foods, focusing on traditional dishes. Methods: The collection of food samples was done using stratified sampling techniques. These samples were classified into five strata, taking into account variation by geographical area (Mount Lebanon, Bekaa, Beirut, Tripoli, and Saida). The number of samples per governorate was estimated to be 30 according to the variability in the dishes' composition. Food samples were chemically analyzed for total sugar, salt, and iron. Results: Among all the governorates, all the tested traditional Lebanese dishes contained little total sugar. More than 60% of the samples tested were rich in sodium. The sodium content ranges were 120-720 mg/100 g in Mount Lebanon, 240-960 mg/100 g in Bekaa, 80-520 mg/100g in Beirut, 252-1952 mg/100g in Tripoli and 40-680 mg/100 g in Saida. The highest mean amount of sodium was observed in the dishes Fatayer Sabanikh and Malfouf Mehche (≥ 600 mg/100 g). Furthermore, more than 80% of the samples had poor amounts of iron in all governorates. Conclusion: This study emphasizes the need for multi-cultural education and awareness on food sources of salt and iron, and the health effects regarding high intake of salt and low intake of iron. This study is a stepping stone for further research exploring total sugar, salt and iron content of traditional dishes, as well as potential intake by individuals in the Lebanese population.


Subject(s)
Diet , Iron , Humans , Lebanon , Nutritive Value , Sugars
10.
Int J Mol Sci ; 21(17)2020 Aug 29.
Article in English | MEDLINE | ID: mdl-32872422

ABSTRACT

Recent experimental findings suggest the involvement of the 26S proteasome, the main protease active in eukaryotic cells, in the process that leads mammalian sperm to become fully fertile, so-called capacitation. Unfortunately, its role in male gametes signaling is still far from being completely understood. For this reason, here, we realized a computational model, based on network theory, with the aim of rebuilding and exploring its signaling cascade. As a result, we found that the 26S proteasome is part of a signal transduction system that recognizes the bicarbonate ion as an input terminal and two intermediate layers of information processing. The first is under the control of the 26S proteasome and protein kinase A (PKA), which are strongly interconnected, while the latter depends on intracellular calcium concentrations. Both are active in modulating sperm function by influencing the protein phosphorylation pattern and then controlling several key events in sperm capacitation, such as membrane and cytoskeleton remodeling. Then, we found different clusters of molecules possibly involved in this pathway and connecting it to the immune system. In conclusion, this work adds a piece to the puzzle of protease and kinase crosstalk involved in the physiology of sperm cells.


Subject(s)
Calcium/metabolism , Cyclic AMP-Dependent Protein Kinases/metabolism , Proteasome Endopeptidase Complex/metabolism , Spermatozoa/physiology , Animals , Bicarbonates/metabolism , Humans , Male , Models, Theoretical , Neural Networks, Computer , Phosphorylation , Signal Transduction , Sperm Capacitation
12.
Toxicol Rep ; 7: 1025-1031, 2020.
Article in English | MEDLINE | ID: mdl-32913715

ABSTRACT

Widely used for a variety of applications, levels of dietary aluminum (Al) have seen a perpetual rise in Lebanon, leading to noticeable effects upon the human body. This study aims to estimate the rates of Al contaminated food consumption and quantify the Al present in different dietary matrices, revealing the major contributors to Al exposure for the Lebanese population. A cross-sectional study was conducted using a customized, self-reported Electronic Food Frequency Questionnaire (E-FFQ) using Curve®, targeting individuals between the ages of 18 and 64 from different Lebanese regions, distributed proportionally. The selection of food was based upon the results of the French EAT2 study. Al levels in food were analyzed using Flame Atomic Absorption Spectrometry (FAAS) after acid digestion. The E-FFQ was completed by 167 respondents. Data analysis was performed on SPSS version 25. Additionally, 97 food items were studied in 2018. Al levels had a mean of 3.56 ± 2.08 mg/kg (ranging from 0.14 to 9.37). The highest Al levels were found in vegetables, followed by sauces and condiments, candies, and ready meals. The Provisional Tolerable Weekly Intake (PTWI) of Al was set at 0.50 mg/kg body weight (60 Kg/person). Al mean Daily Dietary Exposure (DDE) was estimated to be 4341.18 µg/day, with the highest food exposure coming from lettuce, soft drinks, ice cream and tea. Al ingestion rates for the adult Lebanese population does not exceed the international established thresholds of tolerable intake (1 mg/kg/week). National recommendation should be developed to control the presence of metal for food safety purposes.

13.
Int J Surg Case Rep ; 75: 394-397, 2020.
Article in English | MEDLINE | ID: mdl-32992096

ABSTRACT

INTRODUCTION: Acute lower gastrointestinal haemorrhage can potentially be life-threatening. We present a case of a massive rectal bleed which was managed successfully with a balloon tamponade device designed for upper gastrointestinal haemorrhage. PRESENTATION OF CASE: A 75-year-old gentleman, with a history of human immunodeficiency virus and cirrhosis with portal hypertension, presented with bright red rectal bleeding. Investigations showed a low haemoglobin level (74 g/L) and deranged clotting. Oesophago-gastro-duodenoscopy demonstrated no fresh or altered blood. Flexible sigmoidoscopy revealed active bleeding from a varix within the anterior rectal wall 4 cm from the anal verge. Efforts to stop the bleeding, including endoscopic clips, adrenaline injection and rectal packing, were unsuccessful and the patient became haemodynamically unstable. A Sengstaken-Blakemore tube was inserted per rectum and the gastric balloon was inflated to tamponade the lower rectum. The oesophageal balloon was then inflated to hold the gastric balloon firmly in place. A computed tomography angiogram demonstrated no evidence of haemorrhage with balloon tamponade. After 36 h, the balloon was removed with no further episodes of bleeding. DISCUSSION: The application of a balloon tamponade device should be considered in the management algorithm for acute lower gastrointestinal bleed. Advantages include its rapid insertion, immediate results and ability to measure further bleeding after the catheter has been placed. CONCLUSION: Sengstaken-Blakemore tube per rectum may effectively control massive low rectal bleeding when alternative methods have been unsuccessful.

14.
Food Addit Contam Part B Surveill ; 13(2): 121-129, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32200691

ABSTRACT

The treatment of animals with antimicrobial products may lead to the contamination of edible tissues by their residues, which may represent a risk to human health. Therefore, this study aimed to determine the level of antimicrobial residues in food-producing animals (chicken, beef, and milk) in Lebanon. A total of 310 samples were collected and analysed using an LC-MS/MS for the determination of 48 compounds belonging to different families in order to map their compliance according to the European Commission decision 2002/657/EC. Results show that 60% of the analysed samples were not contaminated by any residue, while 12% presented a concentration higher than the MRLs for tetracyclines, sulphonamides, quinolones, and macrolides. Results revealed that chicken were the most contaminated by antimicrobial residues, when compared to beef and milk. The obtained results demonstrate the uncontrolled use of antimicrobials in some Lebanese farms and claim for better management of livestock.


Subject(s)
Anti-Infective Agents/analysis , Drug Residues/analysis , Food Contamination/analysis , Meat/analysis , Milk/chemistry , Animals , Cattle , Chickens , Lebanon
15.
Food Chem Toxicol ; 138: 111204, 2020 Apr.
Article in English | MEDLINE | ID: mdl-32081729

ABSTRACT

A new method, using liquid chromatography coupled to mass spectrometry (LC-MS/MS) for the detection of fourteen natural and synthetic hormones in muscles, was validated in other bovine matrices (liver, kidney, bile and hair) according to the Decision Commission 2002/657/EC. As result, this method demonstrates good linearity (R2 > 0.99) as well as accuracy with coefficients of variation for repeatability and reproducibility lower than 23%. Moreover, the values of decision limit (CCα) and detection capability (CCß) were determined indicating values ranging from 0.13 to 0.86 µg/kg and 0.25-1.72 µg/k for the majority of analytes. Recovery rate in the different matrices varied from 51.5 to 107%. Indeed, this method has been successfully applied to detect anabolic hormones in eighty-eight samples (muscle, liver, kidney, and bile) collected from different local slaughterhouses. Results showed that progesterone was found in 30 samples at concentrations ranging from 0.11 to 11.7 µg/kg, while testosterone was detected in 34 samples at concentrations ranging from 0.5 to 9.52 µg/kg. All bile samples contain epi-testosterone at concentration ranging from 0.89 to 280 µg/kg. These obtained data were used to calculate the estimated daily intake, hazard quotient and hazard index as exposure assessment.


Subject(s)
Chromatography, High Pressure Liquid , Tandem Mass Spectrometry , Animals , Bile/chemistry , Cattle , Hair/chemistry , Kidney/chemistry , Limit of Detection , Liver/chemistry , Muscles/chemistry , Progesterone/analysis , Reproducibility of Results , Risk Assessment , Sensitivity and Specificity , Testosterone/analysis
16.
Food Addit Contam Part B Surveill ; 12(2): 81-89, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30642226

ABSTRACT

In Lebanon, apples are among the most consumed commodities; however, pesticide residues in apples have not been evaluated so far. Therefore, this study presents the occurrence of pesticide residues in apples produced in Lebanon during 2012-2016. A total of 212 samples were analysed for the presence of pesticides using the QuEChERS multi-residue extraction method, followed by GC-MS. Pesticide residues were not observed in 23% of the samples. Whereas pesticide residues were found in 77% of the samples, among them 61% exceeded the maximum residue limits (MRL) and 16% contained residues below the MRL. The most frequently detected pesticide residues were chlorpyrifos (n = 142), methidathion (n = 34), cypermethrin (n = 21), lambda-cyhalothrin (n = 16), myclobutanil (n = 13) and diazinon (n = 9). A preliminary long-term exposure assessment for the detected pesticides in apples showed that Hazard Quotient (HQ) was in the range of 0.1-8% of the ADI's, indicating no risk to human health.


Subject(s)
Fruit/chemistry , Malus/chemistry , Risk Assessment , Chlorpyrifos/analysis , Food Contamination/analysis , Food Contamination/prevention & control , Humans , Lebanon , Maximum Allowable Concentration , Nitriles/analysis , Organothiophosphorus Compounds/analysis , Pesticide Residues/analysis , Pyrethrins/analysis , Quality Control , Reproducibility of Results
17.
J Mass Spectrom ; 53(7): 614-623, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29672996

ABSTRACT

Sulfonamides (SNs) are synthetic antimicrobial agents. These substances are continually introduced into the environment, and they may spread and maintain bacterial resistance in the different compartments. The chlorination of 2 SNs, namely, sulfamethazine (SMT) and sulfamethoxypyridazine (SMP), was investigated to study their reactivity with chlorine at typical concentrations for water treatment conditions. Experiments conducted in purified water show an acceleration of SMT and SMP degradation of a factor 1.5 by comparison to drinking water matrix. This difference is due to pH variation and competitive reactions between SNs and mineral and organic compounds, with chlorine in drinking water. In the presence of an excess of chlorine (6.7 µmol·L-1 ) in ultrapure water at pH 7.2, second-order degradation rate constants were equal to 4.5 × 102 M-1 ·s-1 and 5.2 × 102 M-1 ·s-1 for SMT and SMP, respectively. The structures of transformation products were investigated by liquid chromatography tandem mass spectrometry analyses with equimolar concentrations between chlorine and SNs. SO2 elimination, cyclization, and electrophilic substitutions were the main pathways of by-products formation. Moreover, the toxicity of the proposed structures was predicted by using toxicity estimation software tool program. The results indicated that most by-products may present developmental toxicity.


Subject(s)
Anti-Bacterial Agents/chemistry , Chlorine/chemistry , Sulfamethazine/chemistry , Sulfamethoxypyridazine/chemistry , Water Pollutants, Chemical/chemistry , Chromatography, High Pressure Liquid , Computer Simulation , Halogenation , Kinetics , Oxidation-Reduction , Sulfamethazine/toxicity , Sulfamethoxypyridazine/toxicity , Tandem Mass Spectrometry , Water Pollutants, Chemical/toxicity , Water Purification
18.
Environ Sci Pollut Res Int ; 25(35): 34863-34872, 2018 Dec.
Article in English | MEDLINE | ID: mdl-29192403

ABSTRACT

Sulfaquinoxaline (SQX) is an antimicrobial of the sulfonamide class, frequently detected at low levels in drinking and surface water as organic micropollutant. The main goal of the present study is the evaluation of SQX reactivity during chlorination and UV irradiations which are two processes mainly used in water treatment plants. The SQX transformation by chlorination and UV lights (254 nm) was investigated in purified water at common conditions used for water disinfection (pH = 7.2, temperature = 25 °C, [chlorine] = 3 mg L-1). The result shows a slow degradation of SQX during photolysis compared with chlorination process. Kinetic studies that fitted a fluence-based first-order kinetic model were used to determine the kinetic constants of SQX degradation; they were equal to 0.7 × 10-4 and 0.7 × 10-2 s-1corresponding to the half time lives of 162 and 1.64 min during photolysis and chlorination, respectively. In the second step, seven by-products were generated during a chlorination and photo-transformation of SQX and identified using liquid chromatography with electrospray ionization and tandem mass spectrometry (MS-MS). SO2 extrusion and direct decomposition were the common degradation pathway during photolysis and chlorination. Hydroxylation and isomerization were observed during photodegradation only while electrophilic substitution was observed during chlorination process.


Subject(s)
Chlorine/chemistry , Models, Chemical , Sulfaquinoxaline/chemistry , Water Pollutants, Chemical/chemistry , Chromatography, Liquid , Disinfection/methods , Halogenation , Hydroxylation , Kinetics , Photochemical Processes , Photolysis , Tandem Mass Spectrometry , Ultraviolet Rays , Water Pollutants, Chemical/analysis , Water Purification/methods
19.
Chemosphere ; 193: 329-336, 2018 Feb.
Article in English | MEDLINE | ID: mdl-29149708

ABSTRACT

Kinetics of photodegradation of novel oral anticoagulants dabigatran, rivaroxaban, and apixaban were studied under simulated solar light irradiation in purified, mineral, and river waters. Dabigatran and rivaroxaban underwent direct photolysis with polychromatic quantum yields of 2.2 × 10-4 and 4.4 × 10-2, respectively. The direct photodegradation of apixaban was not observed after 19 h of irradiation. Kinetics of degradation of rivaroxaban was not impacted by the nature of the aqueous matrix while photosensitization from nitrate ions was observed for dabigatran and apixaban dissolved in a mineral water. The photosensitized reactions were limited in the tested river water (Isle River, Périgueux, France) certainly due to the hydroxyl radical scavenging effect of the dissolved organic matter. The study of photoproduct structures allowed to identify two compounds for dabigatran. One of them is the 4-aminobenzamidine while the second one is a cyclization product. In the case of rivaroxaban, as studied by very high field NMR, only one photoproduct was observed i.e. a photoisomer. Finally, seven photoproducts were clearly identified from the degradation of apixaban under simulated solar light.


Subject(s)
Anticoagulants/radiation effects , Fresh Water/chemistry , Photolysis/radiation effects , Sunlight , Benzamidines , France , Hydroxyl Radical , Kinetics , Pyrazoles , Pyridones , Water Pollutants, Chemical/analysis , Water Pollutants, Chemical/radiation effects
20.
Article in English | MEDLINE | ID: mdl-28869744

ABSTRACT

This study examines the behaviour of volatile perfluorinated carboxylic acids used as ion-pairing reagents for the separation of multiclass antimicrobial residues in honey (tetracyclines, sulphonamides, macrolides, and aminoglycosides). Heptafluorobutanoic acid and pentafluoropentanoic acid were compared as mobile phase additives at concentrations of 0-20 mmol.L-1 using reversed-phase chromatography. Our objective was to find optimal conditions that enable the separation of antimicrobials with a minimum loss in sensitivity and efficiency. The influence of ion pairing on chromatographic performance was examined. Results showed that heptafluorobutanoic acid was able to separate aminoglycosides faster and more efficiently than pentafluoropentanoic acid, but at low concentrations of heptafluorobutanoic acid between 2.5 and 5 mM, tetracyclines showed poor chromatographic efficiency. A concentration of 10 mM was found to be optimal for all studied veterinary drugs. The method was then applied to determine multiclass antimicrobial residues in honey. Based on validation data, the mean recoveries of analytes ranged between 93% and 104%, and the intermediate precisions were <21%. The decision limit (CCα) and detection capability (CCß) were in the ranges of 5-25 and 7-33 µg kg-1, respectively. The method was found to be suitable for use in analysis of veterinary drugs with a broader group of compounds found in food-producing animals.


Subject(s)
Anti-Infective Agents/analysis , Carboxylic Acids/analysis , Drug Residues/analysis , Fluorocarbons/analysis , Honey/analysis , Chromatography, Liquid , Tandem Mass Spectrometry
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