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The COVID-19 pandemic process may affect the physical and psychosocial health in patients with chronic kidney disease (CKD). The aim of this study was to compare the quality of life, physical activity, fear of COVID-19 and mental health in CKD patients and healthy individualsand compare the aforementioned parameters in end-stage renal disease (ESRD) and renal transplantation (RTx) patients during the pandemic. Eighty-two patients (33 ESRD, 49 RTx) and age-gender matched 108 healthy individuals were included. Quality of life (Short Form 36 Health Survey Questionnaire-SF-36), physical activity (short form of the International Physical Activity Questionnaire -IPAQ-SF), fear of COVID-19 (Fear of COVID-19 Scale-FCV-19S) and mental health (Hospital Anxiety and Depression Scale-HADS) were evaluated. Physical activity levels and all SF-36 scores except mental health in CKD patients were significantly lower than healthy individuals (p < 0.05). FCV-19S and HADS scores were similar between the groups (p > 0.05). ESRD patients' pain and general health perceptions scores of SF-36 were lower than RTx patients' (p < 0.05). Quality of life and physical activity levels were worse in CKD patients compared to healthy individuals during the pandemic. The participants had fear of COVID-19, poor mental health and low physical activity. For these reasons, psychosocial and physical activity interventions for the both groups may be beneficial for the affected outcomes during COVID-19 pandemic.
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COVID-19 , Falência Renal Crônica , Insuficiência Renal Crônica , Humanos , Qualidade de Vida , COVID-19/epidemiologia , Pandemias , Depressão/psicologia , Insuficiência Renal Crônica/epidemiologia , Insuficiência Renal Crônica/psicologia , Falência Renal Crônica/epidemiologia , Exercício FísicoRESUMO
OBJECTIVE: The 6-minute pegboard and ring test (6PBRT) is a test of upper-extremity functional capacity designed for and validated in chronic obstructive pulmonary disease. The aim of this study was to evaluate the validity and reliability of the 6PBRT in asthma patients. METHODS: Thirty-four adults (30 women, 4 men) with well-controlled asthma were included. Unsupported upper-extremity exercise capacity was assessed using 6PBRT, maximal arm exercise capacity using an arm ergometer, handgrip strength using a hand dynamometer, activities of daily living with the London Chest Activities of Daily Living Scale (LCADL), Milliken ADL scale (MAS) and health-related quality of life using the Asthma Quality of Life Questionnaire (AQLQ) and Health Assessment Questionnaire Disability Index (HAQ-DI). RESULTS: The 6PBRT showed moderate to excellent test-retest reliability with an intraclass correlation coefficient (ICC) value of 0.872 [95% confidence interval (CI) 0.702-0.941]. The 6PBRT was reproducible according to Bland-Altman analysis, with upper and lower limits of agreement of 53.51 and -25.08 rings moved, respectively. The 6PBRT score was significantly correlated with maximum workload (r = 0.514, p = 0.002) achieved in the arm ergometer test, change in dyspnea during 6PBRT (r = -0.402, p = 0.020), LCADL-self-care (r = -0.364, p = 0.037), MAS total (r = 0.483, p = 0.005), AQLQ-symptom domain (r = 0.420, p = 0.026) and HAQ-DI total scores (r = -0.390, p = 0.025). CONCLUSIONS: The 6PBRT can be used as a valid and reliable test to evaluate functional arm exercise capacity in patients with well-controlled asthma.
Assuntos
Asma , Força da Mão , Atividades Cotidianas , Adulto , Asma/diagnóstico , Teste de Esforço , Feminino , Humanos , Masculino , Qualidade de Vida , Reprodutibilidade dos Testes , Inquéritos e QuestionáriosRESUMO
This study describes the development of a sensitive and accurate dispersive liquid-liquid microextraction strategy for the preconcentration and determination of selected pesticides in wastewater and lake water samples by gas chromatography-mass spectrometry. Determination of these pesticides at high accuracy and precision is important because they can be still be found in environmental samples. The type of extraction solvent and type of disperser solvent were optimized using the univariate approach. Furthermore, a Box-Behnken experimental design was used to set up a working model made up of 18 combinations of three variables, tested at three levels. The parameters fitted into the design model were volume of extraction solvent, disperser solvent volume, and mixing period. Analysis of variance was used to evaluate the experimental data to determine the significance of extraction variables and their interactions, before selecting optimum extraction conditions. The method was then applied to aqueous standard solutions between 2.0 and 500 µg L-1, and the limit of detection (LOD) and quantification (LOQ) values obtained for the analytes were between 0.37-2.8 and 1.2-9.4 µg L-1, respectively. The percent recoveries were calculated in the range of 92-114 and 96-110% for wastewater and lake water, respectively. These results validated the accuracy and applicability of the method to the selected matrices.
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Monitoramento Ambiental , Microextração em Fase Líquida , Praguicidas/análise , Poluentes Químicos da Água , Clorpirifos , Endossulfano , Cromatografia Gasosa-Espectrometria de Massas , Lagos/química , Fenilcarbamatos , Tiadiazóis/análise , Águas Residuárias/químicaRESUMO
This study presents a green analytical method for palladium determination by slotted quartz tube flame atomic absorption spectrometry (SQT-FAAS) following switchable liquid-liquid microextraction (SLLME). Efficient extraction of palladium was facilitated by complexation with a Schiff base ligand, synthesized specifically for this study. A three-stage thorough optimization procedure was carried out to boost the absorbance output of palladium. Complex formation was the first stage, and parameters evaluated included buffer solution pH and amount, concentration of ligand, and mixing period. The amount of switchable solvent and concentration and amount of sodium hydroxide and acid amount were optimized in the second stage. Optimization of sample and fuel flow rates and SQT parameters completed the third stage of optimization, and all optimum parameters were used to determine analytical performance of the method. The method had a broad linear dynamic range, and the calibration plots showed good linearity with R2 values greater than 0.9991. The limits of detection and quantification of the SLLME-SQT-FAAS method were 15 and 50 µg/L, respectively. The precision of the method, expressed as percent relative standard deviation, was below 9.0% for all measurements. Spiked recovery results performed for a palladium electroplating bath solution gave poor results when quantified against aqueous calibration standards. Matrix matching was therefore used to improve recovery results which ranged between 97 and 105% for four different spike concentrations.
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Monitoramento Ambiental/métodos , Microextração em Fase Líquida/métodos , Paládio/análise , Espectrofotometria Atômica/métodos , Poluentes Químicos da Água/análise , Concentração de Íons de Hidrogênio , Ligantes , Limite de Detecção , Quartzo/química , Bases de Schiff/química , Solventes/análise , Água/químicaRESUMO
Presented in this study is a simple but efficient switchable polarity solvent microextraction strategy for etrimfos preconcentration from water and food samples for quantification by gas chromatography mass spectrometry. Repeatability of the extraction process and instrumental measurements were enhanced by using deuterated bisphenol A as internal standard. Significant parameters of the extraction method were fitted into an experimental design model to study the effects of parameters on extraction output, as well as mutual effects of combined parameters. The design model was formed with 51 experimented data obtained from the combination of sodium hydroxide volume, switchable solvent volume, and vortex period at three levels. The method was validated by applying optimum conditions attained from the model predictor. The detection limit was found to be 1.3 ng/mL and it corresponded to an enhancement factor of about 54 folds when compared to direct GC-MS measurement. Etrimfos was not detected in the water and food samples tested but the results (92-107%) obtained from spiked recovery experiments established that etrimfos when present in the selected matrices can be accurately and precisely quantified.
Assuntos
Poluentes Ambientais/análise , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Cromatografia Gasosa-Espectrometria de Massas , Microextração em Fase Líquida , Organotiofosfatos/análise , Água/química , Compostos Benzidrílicos/análise , Compostos Benzidrílicos/normas , Poluentes Ambientais/química , Poluentes Ambientais/isolamento & purificação , Limite de Detecção , Organotiofosfatos/química , Organotiofosfatos/isolamento & purificação , Fenóis/análise , Fenóis/normas , Reprodutibilidade dos Testes , Projetos de Pesquisa , Solventes/químicaRESUMO
In this study, the detection power of a gas chromatography mass spectrometer (GC-MS) for procymidone and chlorflurenol was significantly enhanced using switchable solvent liquid phase microextraction (SS-LPME) as a preconcentration tool. This was achieved by a comprehensive optimization of significant parameters to the SS-LPME method such as switchable solvent amount, concentration and amount of sodium hydroxide, pH effect and mixing effect. The optimum experimental conditions obtained were used to determine analytical figures of merit for the analytes. The limits of detection obtained were 0.44 and 2.9 ng/mL for procymidone and chlorflurenol, respectively. The optimum method was applied to water sampled from an irrigation canal and two wastewater samples. The samples were spiked at two concentrations and the percent recovery results obtained ranged between 86 and 115% for both analytes. The recovery results together with the low standard deviations recorded validated the method as accurate and precise.
Assuntos
Compostos Bicíclicos com Pontes/análise , Fluorenos/análise , Águas Residuárias/química , Poluentes Químicos da Água/análise , Irrigação Agrícola , Compostos Bicíclicos com Pontes/química , Fluorenos/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Microextração em Fase Líquida/métodos , Solventes/química , Água/químicaRESUMO
Antimony is known to have some adverse health effects on human health. Flame atomic absorption spectrometry (FAAS) is a widely used instrumental for the determination of antimony and other metals. However, it lacks the sensitivity to determine these metals at trace levels. This study was aimed at overcoming this setback by using hydrogen assisted T-shaped slotted quartz tube technique to preconcentrate and determine antimony by FAAS. All the system parameters were optimized to enhance the detection power of the system. Under the optimum experimental conditions, the limits of detection and quantification were found to be 0.75 and 2.49 µg L-1, respectively with R2 value of 0.9999. Accuracy of the developed method was validated by experimental results agreeing to the certified value of a standard reference material. Recovery studies were also carried out to determine the method's applicability to tap and mineral water samples, and the results obtained were appreciable.
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Antimônio/análise , Quartzo/química , Espectrofotometria Atômica , Hidrogênio/química , Limite de Detecção , Sensibilidade e EspecificidadeRESUMO
Switchable solvent liquid-phase microextraction was combined with gas chromatography and mass spectrometry to improve the sensitivity and accuracy for the determination of selected endocrine disruptors, pesticides, and hormones. The extraction method was used to complement gas chromatography with mass spectrometry by preconcentrating analytes for trace determinations. A Box-Behnken experimental design was used to evaluate the main variables and their interaction effects, and optimum parameters were selected based on the model of experimented results. Application of optimum extraction conditions to mixed standard solutions yielded limits of detection and quantitation values between 0.20-13 and 0.90-46 ng/mL, respectively. The accuracy and the applicability of the developed method was checked in tap water and two different wastewater samples by spiked recovery tests. The percent recoveries recorded for the analytes were between 91 and 110%, and percent relative standard deviation values were all below 10%. The results indicate that the method can be used for the accurate and sensitive determination of these analytes in the presented matrixes.
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We aimed to assess element status in whole blood and tooth dentin and identify their correlations in overweight or obese children without additional metabolic risk factors. In a case-control study, 40 overweight and 80 normal weight children aged 6-10 years were enrolled. Samples of blood and tooth were collected. While all studied elements were similar in groups in univariate analysis, after adjustment for confounding factors, tooth Mn levels were lower and blood Zn levels were higher in the overweight/obese group (p = 0.049 and p = 0.032, respectively). A significant correlation in blood and tooth dentin levels of Sr and Zn was detected in both groups. In both biological substances, the concentrations of elements did not differ significantly in overweight children without metabolic comorbidities compared to healthy children of normal weight. Presence of low Mn levels in tooth dentin and high Zn levels in blood samples should be explored in further studies.
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In this study, a switchable solvent was used to preconcentrate trace amounts of Cd from aqueous solution for its determination by flame atomic absorption spectrometry (FAAS). Protonation of N,N-dimethylbenzylamine by dry ice (solid CO2) made it water soluble, and addition of sodium hydroxide converted it back to its original nonionic state for phase separation and subsequent extraction of Cd. A slotted quartz tube (SQT) was attached to the flame burner head to increase the residence time of Cd atoms in the light path. Under the optimum conditions, limits of detection and quantification were determined as 0.7 and 2.6 µg L-1, respectively. Low relative standard deviations calculated from seven replicate measurements of the lowest concentration indicated high precision. Accuracy of the developed method was checked by using a standard reference material (SRM 1633c). Spiked recovery tests were also performed on lake water and wastewater samples at different concentrations to check the applicability of the developed method, and the results obtained (90-103%) established high recovery.
Assuntos
Cádmio/análise , Monitoramento Ambiental/métodos , Microextração em Fase Líquida/métodos , Poluentes Químicos da Água/análise , Água Doce/análise , Concentração de Íons de Hidrogênio , Solventes/análise , Espectrofotometria Atômica/métodos , Águas Residuárias/análiseRESUMO
In this study, dispersive liquid-liquid microextraction was systematically optimized for the preconcentration of nickel after forming a complex with diphenylcarbazone. The measurement output of the flame atomic absorption spectrometer was further enhanced by fitting a custom-cut slotted quartz tube to the flame burner head. The extraction method increased the amount of nickel reaching the flame and the slotted quartz tube increased the residence time of nickel atoms in the flame to record higher absorbance. Two methods combined to give about 90 fold enhancement in sensitivity over the conventional flame atomic absorption spectrometry. The optimized method was applicable over a wide linear concentration range, and it gave a detection limit of 2.1 µg L-1. Low relative standard deviations at the lowest concentration in the linear calibration plot indicated high precision for both extraction process and instrumental measurements. A coal fly ash standard reference material (SRM 1633c) was used to determine the accuracy of the method, and experimented results were compatible with the certified value. Spiked recovery tests were also used to validate the applicability of the method.
Assuntos
Poluentes Ambientais/análise , Níquel/análise , Espectrofotometria Atômica/métodos , Poluentes Ambientais/química , Concentração de Íons de Hidrogênio , Microextração em Fase Líquida/métodos , Níquel/química , Quartzo/químicaRESUMO
INTRODUCTION: Kartagener's syndrome (KS), consisting of bronchiectasis, situs inversus totalis, and sinusitis, is a subtype of primary ciliary dyskinesia (PCD). The presence of KS may affect respiratory and physical functions. PURPOSE: This study aimed to compare respiratory functions, exercise capacity, muscle strength, and physical activity levels among children with PCD with/without KS and healthy peers. METHODS: Fifteen patients with KS, 23 with PCD without KS, and 27 controls were compared. Pulmonary function, functional exercise capacity (6-minute walk test - 6MWT), maximal inspiratory, expiratory (MIP, MEP), and skeletal muscle strength, inspiratory muscle endurance (IME), and physical activity level were evaluated. RESULTS: The forced expiratory volume in one second (FEV1) % (p = .009), forced expiratory flow from 25%-75% (FEF25-75%) % (p = .001), MIP (p = .034), MEP (p = .003), 6MWT distance (p = .001), and daily steps (p = .034) were significantly different among the groups. Quadriceps femoris (QF) muscle strength and IME were similar in groups (p Ë .05). FEV1% (p = .002), FEF25-75% % (p = .001), MIP (p = .027), MEP (p = .001), and 6MWT distance (p = .003) in patients with KS; 6MWT distance (p = .003) in patients with PCD without KS was significantly lower than controls. CONCLUSION: The presence of KS affects pulmonary function, respiratory muscle strength, and physical activity more. Exercise capacity and physical activity levels are decreased, inspiratory muscle endurance and QF muscle strength are preserved in patients with KS and PCD without KS. Kartagener's syndrome further impairs pulmonary and extrapulmonary outcomes; the reasons should be investigated, and the necessity of rehabilitation approaches that will prevent deterioration come to the fore.
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INTRODUCTION: Assessment of exercise capacity is important for information about lung function and prognosis in primary ciliary dyskinesia (PCD). In addition, deterioration in the pulmonary system may affect cough efficiency, posture, and thoracoabdominal mobility. In turn, this deterioration may also disturb the psychological function of patients with PCD. Therefore, this study aimed to compare exercise capacity, cough strength, thoracoabdominal mobility, posture, and depression in children with PCD and healthy peers. METHODS: Twenty-seven patients with PCD and 28 healthy peers were included. Aerobic exercise capacity (3-min step test), cough strength (peak expiratory flow meter), thoracoabdominal mobility (upper chest, lower chest, and abdomen), posture (Corbin postural assessment scale), and depression (Children's Depression Inventory) were evaluated. RESULTS: Patients' number of steps completed, cough strength, and thoracoabdominal mobility were significantly decreased; total posture and depression scores were higher compared with healthy controls (p< 0.05). There was a significant relationship between cough strength and maximal expiratory strength (r = 0.541, p= 0.004) and total number of steps (r = 0.509, p= 0.007) in the patients. CONCLUSION: Aerobic exercise capacity, cough strength, and thoracoabdominal mobility were impaired, posture was deteriorated, and depression perception elevated in children with PCD compared to healthy peers. Furthermore, aerobic exercise capacity and maximal expiratory strength are related to cough strength in these patients. Rehabilitation programs including aerobic and resistive exercise training, deep breathing and postural exercise, and nutrition counseling may improve these results and better be investigated. Trial registration: Clinicaltrials.gov: NCT03370029; December 12, 2017.
Assuntos
Transtornos da Motilidade Ciliar , Tolerância ao Exercício , Criança , Humanos , Tosse , Depressão/etiologia , Exercício Físico , PosturaRESUMO
BACKGROUND: The decline in ambulatory activities and negative alterations in gait characteristics may impair balance and increase fall risk in obstructive lung diseases. Few studies have evaluated balance and gait parameters in individuals with bronchiectasis. PURPOSE: This study aimed to compare the gait parameters and functional balance in individuals with non-cystic fibrosis (CF) bronchiectasis and healthy subjects. METHODS: This cross-sectional and retrospective study analyzed data from 22 individuals with non-CF bronchiectasis and 32 healthy controls recorded between July 2019 and July 2020. Functional balance was assessed using the Timed Up and Go (TUG) test. Gait parameters were evaluated using the Biodex Gait Trainer. Step cycle (s), gait speed (m/s), the number of steps per minute, and ambulation index were measured for 6 min.Results The TUG time (s) was significantly longer (p = .019, effect size = 0.66), and gait speed (m/s) (p Ë 0.001, effect size = 2.47), step cycle (s) (p Ë 0.001, effect size = 2.23), and ambulation index (p Ë 0.001, effect size = 2.56) were significantly reduced in individuals with non-CF bronchiectasis compared with healthy controls. CONCLUSION: Non-CF bronchiectasis is related to unfavorable changes in gait characteristics, such as slower gait speed and the decreased average step cycle. In addition, impairment in functional balance and mobility exists in a small percentage of adults with non-CF bronchiectasis. In comprehensive pulmonary rehabilitation, balance and gait evaluations should be included to prevent falls in adults with non-CF bronchiectasis.
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Bronquiectasia , Marcha , Adulto , Humanos , Estudos Transversais , Estudos Retrospectivos , Fibrose , Equilíbrio PosturalRESUMO
BACKGROUND AND OBJECTIVES: The pathophysiological mechanisms of primary ciliary dyskinesia (PCD) may affect many functions, including respiratory, physical, and health status. This study aimed to compare respiratory muscle strength, inspiratory muscle endurance, muscle strength, exercise capacity, physical activity levels, and quality of life in PCD patients and controls. METHODS: Twenty-seven patients and 28 controls were included. Respiratory muscle strength (maximal inspiratory (MIP) and maximal expiratory (MEP) pressures), inspiratory muscle endurance (incremental threshold loading test), muscle strength (quadriceps femoris, shoulder abductor, elbow flexor, handgrip), exercise capacity (6-min walk test (6MWT)), physical activity and quality of life (QOL-PCD) were evaluated. RESULTS: MIP, inspiratory muscle endurance, quadriceps femoris, and handgrip muscle strength, 6MWT distance, total energy expenditure; childrens' (6-12 years) and their parents' physical function, upper, lower respiratory, and hearing symptoms and treatment burden QOL-PCD subscales scores were significantly lower in patients compared with controls (p < 0.05). The 66.7% of patients did not meet the optimal number of steps. MEP, shoulder abductor, and elbow flexor muscle strength, active energy expenditure, physical activity duration, average metabolic equivalents, number of steps, lying time, and sleep duration; childrens' and their parents' other subscales and adolescents' all QOL-PCD subscales scores were similar between groups (p > 0.05). CONCLUSION: Inspiratory muscle strength and endurance, lower extremity and total muscle strength, exercise capacity, total energy expenditure, and childrens' quality of life are impaired compared to healthy controls. Decreased physical activity level is prevalent in these patients. Effects of pulmonary rehabilitation on these impaired outcomes for PCD patients should be investigated. TRIAL REGISTRATION: Clinicaltrials.gov: NCT03370029; December 12, 2017.
Assuntos
Transtornos da Motilidade Ciliar , Qualidade de Vida , Adolescente , Criança , Estudos Transversais , Exercício Físico/fisiologia , Tolerância ao Exercício/fisiologia , Força da Mão , Humanos , Força Muscular/fisiologia , Músculos RespiratóriosRESUMO
QuEChERS and switchable solvent liquid phase microextraction (SS-LPME) were respectively used as pretreatment and preconcentration tools to allow trace determination of selected organochlorine pesticides and hormones by gas chromatography mass spectrometry (GC-MS). The effects of principal SS-LPME variables and their interactions were evaluated with a Box-Behnken experimental design. The limits of detection obtained by direct GC-MS determination were enhanced by about 33-115 folds under the optimized SS-LPME conditions. The SS-LPME method was applied to tap water, well water, lake water, medical wastewater and tea samples. Satisfactory recovery results were obtained for all but the tea samples using the conventional calibration plot. Matrix matched calibration standards were used to improve the percent recovery of analytes to almost 100% in the tea samples. The combined QuEChERS and SS-LPME method was applied to tomato samples and matrix matching was also used to significantly improve analyte recoveries.
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Cromatografia Gasosa-Espectrometria de Massas/métodos , Hormônios/análise , Hidrocarbonetos Clorados/análise , Microextração em Fase Líquida/métodos , Praguicidas/análise , Solventes/química , Ondas Ultrassônicas , Hormônios/isolamento & purificação , Hidrocarbonetos Clorados/isolamento & purificação , Limite de Detecção , Praguicidas/isolamento & purificação , Águas Residuárias/química , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/isolamento & purificaçãoRESUMO
This study reports a stepwise optimization of switchable liquid-liquid microextraction (SLLME) for cobalt determination by flame atomic absorption spectrometry (FAAS) coupled with a slotted quartz tube (SQT). The main purpose of this study was to develop an accurate and sensitive analytical method for cobalt. Extraction method was used to separate and preconcentrate cobalt from sage tea and vitamin B12 samples after complexing with a Schiff base ligand. 107.7 folds enhancement in detection power under the optimum conditions was recorded with respect to direct FAAS. This enhancement correlated to 3.1⯵g/L limit of detection and 10⯵g/L limit of quantification. The SLLME-SQT-FAAS method was linear over a broad concentration range and low %RSD values established high precision for the method. Appreciable percent recovery results (94-108%) obtained from spiked sage sample and from cobalamin also validated the accuracy of the method.
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Cobalto/análise , Microextração em Fase Líquida/métodos , Espectrofotometria Atômica/métodos , Chás de Ervas/análise , Vitamina B 12/análise , Limite de Detecção , Quartzo , Reprodutibilidade dos Testes , Salvia officinalis/química , Bases de Schiff/química , Espectrofotometria Atômica/instrumentação , Vitamina B 12/químicaRESUMO
This study presents an accurate method for the determination of alkyl phenols and bisphenol A at trace levels using gas chromatography mass spectrometry after preconcentration with switchable liquid-liquid microextraction. In order to achieve high extraction output, the environmentally friendly switchable liquid-liquid microextraction method was optimized by varying parameters such as amount of switchable solvent, sodium hydroxide concentration/amount and the mixing period in a Box-Behnken experimental design. Under optimum extraction conditions, the limits of detection calculated for the analytes were between 0.13 and 0.54â¯ng/mL. The analytes showed good linearity over broad calibration ranges, and low percent relative standard deviations established good precision. Spiked recovery studies were performed on municipal wastewater and tap water to determine the method's suitability and accuracy, and the results (87-106%) obtained were satisfactory. Bisphenol A was detected (4.0-14â¯ng/mL) in four plastic samples investigated under high temperature conditions.
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Compostos Benzidrílicos/análise , Disruptores Endócrinos/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Microextração em Fase Líquida/métodos , Fenóis/análise , Águas Residuárias/química , Poluentes Químicos da Água/análise , Compostos Benzidrílicos/isolamento & purificação , Disruptores Endócrinos/isolamento & purificação , Fenóis/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificaçãoRESUMO
A dispersive liquid-liquid microextraction (DLLME) technique based on a solidification-of-floating-organic-drop (SFOD) procedure was developed for the determination of trace amounts of cadmium (Cd) by using a flame atomic absorption spectrometer (FAAS) fitted with a slotted quartz tube (SQT). The extraction of Cd was achieved by forming a complex with diphenylcarbazone. Parameters affecting the formation of complex and extraction outputs were carefully optimized to obtain high-absorbance signals to achieve lower LODs. An SQT was fitted on top of the flame burner head to further enhance the absorbance of the signals recorded by the FAAS. Coupling the DLLME-SFOD procedure with SQT-FAAS produced an enhancement factor of about 183. The LOD of the method was 0.23 µg/L with an RSD of 3.8%. Matrix-matching was used to overcome any low recovery results obtained with tap water and municipal wastewater.