The current study designed and applied a novel self-ratiometric fluorescent nanosensor composed of green-synthesized silver nanoparticles (Ag-NPs) to determine vanillin in adult and infant foods and ...human plasma. A straightforward microwave-assisted approach is proposed for synthesizing Ag-NPs in less than 1 min using a reducing agent,
tailed pepper
seed extract. The synthesized Ag-NPs had a strong fluorescence with an intense emission band at 360 nm and a shoulder peak at 430 nm when excited at 265 nm. Upon interaction with vanillin, the fluorescence peak of Ag-NPs at 360 nm decreases in a concentration-dependent manner while being shifted to a longer wavelength, 385 nm. Meanwhile, the shoulder fluorescence peak at 430 nm is only slightly affected by vanillin addition. Thus, a new Ag-NP self-ratiometric probe was designed and validated for vanillin determination using the peak at 385 nm and the shoulder peak at 430 as two built-in reference peaks. The optimized system accurately measured vanillin with a detection limit of 9.0 ng/mL and a linear range of 0.05–8.0 μg/mL without needing pre-derivatization or high-cost instrumentation. The method successfully measured vanillin in adult and infant milk formula, biscuits, and human plasma samples with high percentage recoveries (95.3–104.6%) and excellent precision (relative SD; ≤3.85%).
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A rapid, highly sensitive and roubst spectrofluorimetric method was developed for trace analysis of silymarin (SLM) in active pharmaceutical ingredient (API), pharmaceutical preparations and human ...plasma. The proposed method is based on reaction of SLM with a novel reagent; 3-amino-5-pyridin-3-yl-1,2,4-triazole (3-APT); in the presence of 0.04 M sodium hydroxide. The formed fluorescent product was formed within 5 min and was measured at 504 nm after excitation at 390 nm. All reaction parameters were optimized and the proposed method was validated according to ICH guidelines. The developed method was linearly correlated at the concentration range of 0.05–8 μg mL−1 with good correlation coefficient 0.9993, limit of detection 10.79 ng mL−1 and limit of quantitation 32.71 ng mL−1. The relative standard deviations %RSD values were 1.59–2.69% and 1.47–2.62% in case of intra- and inter-day precision, respectively. Computational molecular modeling and NMR spectroscopy were used to identify the reaction mechanism between SLM and 3-APT. The proposed method was employed for determination of SLM in API or bulk material, pharmaceutical capsules and sachets. Further, the method was sensitive enough to be applied for analysis of the free (unconjugated) SLM flavonolignans in human plasma samples.
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•A novel fluorescence probe 3-APT was used for determination of SLM•The reaction occurs within 5 min in presence of 0.04 M NaOH to form stable fluorescent product measured at 504 nm (λex, 390 nm)•The reaction was studied using computational molecular modeling and confirmed using NMR spectroscopy•The proposed method was successfully applied for determination of SLM in API, pharmaceutical preparations and human plasma
•Development of sampling and clean-up procedure using AA-DLLME-SFO.•UHPLC-PDA method development and validation.•Determination of several antibiotics in human plasma.•Therapeutic drug monitoring in ...patients with hospital acquired pneumonia.
An ultra high-performance liquid chromatographic (UHPLC) method with PDA detection was developed and validated for the simultaneous quantification of metronidazole, meropenem, ciprofloxacin, linezolid and piperacillin in human plasma and applied to patients suffering from hospital acquired pneumonia (HAP). The method uses an air assisted dispersive liquid-liquid microextraction for sample preparation. All parameters in the extraction step, including selection of extractant, amount of extractant, ionic strength, pH, and extraction cycles, were investigated and optimized. Chromatography was carried out using a Poroshell 120 SB C18 (50 × 2.1 mm I.D. 2.6 μm particle size) column and a gradient mobile phase consisting of ammonium acetate buffer (10 mM, pH 4.0) (eluent A); and a mixture of acetonitrile-methanol in a ratio (80/20)(eluent B). Ulifloxacin was used as internal standard. The method demonstrated good linearity with correlation coefficients, r2 > 0.9995 for the drugs, as well as high precision (RSD% ≤ 9.87%), accuracy ranged from −8.14% to +8.98. The enrichment factor (EF) obtained ranged within 87 and 121. During the validation, the concentrations of the analytes were found to be stable after 3 freeze-thaw cycles and for at least 24 h after extraction. Subsequently, this method was used to quantify the drugs in patients with HAP in order to establish if the dosage regimen given was sufficient to eradicate the infection at the target site.
The purpose of the research was to develop an improved solid phase microextraction (SPME)-based sampling protocol for the therapeutic drug monitoring of tranexamic acid (TXA) from plasma and urine of ...patients with chronic renal dysfunction (CRD) in order to correct the current dosing schedule to accommodate these patients. A 12-fold improvement in sampling efficiency (25 min for 96 samples -22 s per sample) was achieved with the use of hydrophilic-lipophilic balance (HLB)-coated SPME devices, thereby enabling high throughput profiling of TXA in the plasma and urine of 49 CRD patients undergoing cardiac surgery. A limit of quantification of 10 μg/mL and 25 μg/mL was obtained for plasma and urine respectively while a method accuracy of 103–105% and a precision of less than 8% was achieved. The results from this study were ultimately used by clinicians at the Toronto General Hospital to design a corrective pharmacokinetic dosing schedule for CRD patients. This green method further presents potential application in the clinical field for the fast high throughput monitoring of TXA not only in plasma but also in urine – a biological matrix seldom explored for the analysis of TXA – without the need for solvent-assisted extraction, extensive sample pre-treatment or clean-up, derivatization or excessive pH adjustment to improve amenability for analytical separation.
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⁃Biocompatible TFME used for tranexamic acid profiling in urine and plasma⁃TFME devices directly exposed to native, unprocessed complex biological samples⁃Rapid high throughput TFME protocol produces clean LC-MS amenable extracts⁃No additional sample cleanup, pre-treatment or compound derivatization required⁃First SPME protocol for TXA quantitation from urine
We report on the semi-quantitative analysis of pulsed laser induced plasma species as well as thin film compositions of La0.6Sr0.4MnO3 grown on SrTiO3 substrates under various background pressure ...regimes using an 18O isotope labelled La0.6Sr0.4MnO3 target. The importance of negative metal-oxygen or positive metal-oxygen ions to influence the final oxygen composition of the thin film is illustrated through the use of mass spectrometry, where the chemical reactions between the laser ablated target species with the oxygen background molecules are directly characterized. We find that the influence of metal-oxygen negative ions is not as important as the metal-oxygen positive ions to the final oxygen composition of the LSMO film, due to their low stability in high background partial pressures. Furthermore, we observe that the oxygen incorporated in La0.6Sr0.4MnO3 thin films coming from the target is ~44%, 29% and 1% at 2 × 10−3 mbar, 1 × 10−2 mbar and 2 × 10−1 mbar, respectively. When growing films at 10−1 mbar on 18O2 exchanged substrates, almost all oxygen originates from the background and almost none from the substrate or target.
With the strict standards for steel quality and high production rates, the demand for faster and more convenient slag composition analysis for both electric arc and ladle furnaces has become a major ...issue in industrial steel plants. To overcome the time-delay between slag sampling and results of the slag composition analysis, an on-line slag composition analysis is required. Such a method that can be used in on-line analysis and is also chemically sensitive to the slag composition is optical emission spectroscopy. In this work, the optical emissions from the arc have been measured in an industrial ladle furnace and used for slag composition analysis. This article focuses on CaF2 and MgO, since the CaF2 is a common additive material in the ladle treatment and high MgO content means that the ladle refractory lining is dissolving into the slag. The analysis has been carried out by comparing emission line ratios to the XRF analyzed ratios of CaF2/MgO and MnO/MgO, respectively. The results show that several atomic emissions lines of calcium, magnesium, and manganese can be used to evaluate the CaF2/MgO and MnO/MgO ratios in the slag. It was found out that the plasma temperature derived from Ca I emission lines has a non-linear relation with the CaF2 content of the slag. Additionally, the dissociation pathways of molecular slag components were determined and studied in different plasma temperatures with equilibrium composition computation in order to determine the relations between the slag and plasma compositions.
With the strict standards for steel quality and high production rates, the demand for faster and more convenient slag composition analysis for both electric arc and ladle furnaces has become a major ...issue in industrial steel plants. To overcome the time-delay between slag sampling and results of the slag composition analysis, an on-line slag composition analysis is required. Such a method that can be used in on-line analysis and is also chemically sensitive to the slag composition is optical emission spectroscopy. In this work, the optical emissions from the arc have been measured in an industrial ladle furnace and used for slag composition analysis. This article focuses on CaF2 and MgO, since the CaF2 is a common additive material in the ladle treatment and high MgO content means that the ladle refractory lining is dissolving into the slag. The analysis has been carried out by comparing emission line ratios to the XRF analyzed ratios of CaF2/MgO and MnO/MgO, respectively. The results show that several atomic emissions lines of calcium, magnesium, and manganese can be used to evaluate the CaF2/MgO and MnO/MgO ratios in the slag. It was found out that the plasma temperature derived from Ca I emission lines has a non-linear relation with the CaF2 content of the slag. Additionally, the dissociation pathways of molecular slag components were determined and studied in different plasma temperatures with equilibrium composition computation in order to determine the relations between the slag and plasma compositions.
Medium-chain acyl-CoA dehydrogenase deficiency (MCADD) is the most prevalent mitochondrial fatty acid β-oxidation disorder. In this study, we assessed the variability of the lipid profile in MCADD by ...analysing plasma samples obtained from 25 children with metabolically controlled MCADD (following a normal diet with frequent feeding and under l-carnitine supplementation) and 21 paediatric control subjects (CT). Gas chromatography-mass spectrometry was employed for the analysis of esterified fatty acids, while high-resolution C18-liquid chromatography-mass spectrometry was used to analyse lipid species. We identified a total of 251 lipid species belonging to 15 distinct lipid classes. Principal component analysis revealed a clear distinction between the MCADD and CT groups. Univariate analysis demonstrated that 126 lipid species exhibited significant differences between the two groups. The lipid species that displayed the most pronounced variations included triacylglycerols and phosphatidylcholines containing saturated and monounsaturated fatty acids, specifically C14:0 and C16:0, which were found to be more abundant in MCADD. The observed changes in the plasma lipidome of children with non-decompensated MCADD suggest an underlying alteration in lipid metabolism. Therefore, longitudinal monitoring and further in-depth investigations are warranted to better understand whether such alterations are specific to MCADD children and their potential long-term impacts.
•Rapid FPSE-HPLC-FLD procedure for the determination of three PAHs.•Direct analysis of human plasma samples.•Synergistic effect on sensitivity and selectivity from FPSE-HPLC-FLD configuration.•First ...FPSE application for human exposure evaluation.•Analytical parameters comparable to hyphenated instrumentations.
Following the convenient, yet very powerful pathway to create designer extraction sorbent using sol-gel chemistry, a novel sol-gel phenyl/methyl/poly(dimethylsiloxane) sorbent coating was created on polyester fabric substrate for fabric phase sorptive extraction (FPSE) and was subsequently applied to monitor human exposure to selected polycyclic aromatic hydrocarbons (PAHs) including pyrene, chrysene, and benzoapyrene in plasma samples obtained from tobacco smoker volunteers using high performance liquid chromatography-fluorescence detector (HPLC-FLD). A rapid FPSE-HPLC-FLD method was developed that adequately resolved the PAHs chromatographically, after their successful extraction from human plasma using fabric phase absorption extraction (FPSE) and subsequently analysed in the liquid chromatographic system by means of an analytical column (InterSustain C-18 column 150 × 4.6 mm, 5 μm) using acetonitrile (ACN) and water as mobile phases in gradient elution mode. With the optimized conditions, the retention times were found to be 6.168, 7.214, and 10.404 min for pyrene, chrysene, and benzoapyrene, respectively. The total chromatographic runtime was limited to 12.5 min.
The method, validated through the calculation of all the analytical parameters according to the International Guidelines, was applied to the analysis of real samples collected from informed volunteers. The proposed approach which included the use of sol-gel phenyl/methyl/poly(dimethylsiloxane) immobilized on hydrophobic polyester substrate and C18 stationary phase used in HPLC, has shown a high potential as a rapid tool for future clinical, forensic and toxicological applications, also in the light of the LOD and LOQ values comparable to those normally obtainable with more sophisticated, and expensive instruments that often require highly trained personnel. The results reported here further consolidate the application of FPSE in the analysis of biological samples for both diagnostic and analytical-clinical purposes.
COVID‐19 is a systemic infectious disease that may affect many organs, accompanied by a measurable metabolic dysregulation. The disease is also associated with significant mortality, particularly ...among the elderly, patients with comorbidities, and solid organ transplant recipients. Yet, the largest segment of the patient population is asymptomatic, and most other patients develop mild to moderate symptoms after SARS‐CoV‐2 infection. Here, we have used NMR metabolomics to characterize plasma samples from a cohort of the abovementioned group of COVID‐19 patients (n = 69), between 3 and 10 months after diagnosis, and compared them with a set of reference samples from individuals never infected by the virus (n = 71). Our results indicate that half of the patient population show abnormal metabolism including porphyrin levels and altered lipoprotein profiles six months after the infection, while the other half show little molecular record of the disease. Remarkably, most of these patients are asymptomatic or mild COVID‐19 patients, and we hypothesize that this is due to a metabolic reflection of the immune response stress.
We have used NMR‐based metabolomics to characterize plasma samples from a cohort of recovered COVID‐19 patients, six months on average after diagnosis. Our results show that half the patient population have abnormal metabolism and altered lipoprotein profiles while the other moiety shows little molecular record of the disease.
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