Development of a new magnetic solid-phase extraction method prior to HPLC determination of naproxen in pharmaceutical products and water samples.

In this study, a new magnetic solid phase extraction based on magnetic composite modified with biochar obtained from pumpkin peel was developed for the enrichment and extraction of Naproxen in lake water, tablet and urine samples. The effects of main parameters such as pH, extraction time, amount of adsorbent and sample volume, which affect magnetic solid phase extraction, were investigated. Under optimal conditions, intraday and interday precision values for naproxen were below 5.9, with accuracy (relative error) better than 7.0 %. The detection limit and preliminary concentration factor were 12 ng/mL and 10, respectively. The method proposed here can be used for routine analysis of naproxen in lake water, urine and tablets.

The relationship between lymphocyte DNA damage, coronary artery disease, and blood trace elements.

Somatic DNA damage and causative factors (occupational exposures, foods, habits, etc.) are thought to contribute to the pathogenesis of atherosclerosis, although knowledge about their role in coronary artery disease (CAD) is still insufficient. This study aimed to determine the effects of lymphocyte-DNA damage and blood trace element concentrations on CAD. The single-cell alkaline comet was used in the measuring of the lymphocyte DNA damage in blood samples obtained from patients (n = 99) whose CAD grade was determined by the syntax score while the angiographic intervention was carried out. Blood trace element (n = 14) concentrations were monitored by the inductively coupled plasma-optical emission spectroscopy (ICP-OES) after microwave digestion. The relationship between the DNA damage frequencies of the participants and their syntax scores, blood trace element concentrations, and other demographic and clinic parameters were statistically analyzed. Significant correlations were detected between comet data and syntax score (r = 0.858, P < .001), age (r = 0.337, P < .001), blood-urea (r = 0.360, P < .001), creatinine (r = 0.388, P < .001), HbA1c (0.218, P < .05), ECG-QRS time (r = 0.286, P < .01), ECHO-EF (r = -0.377, P < .001), and platelet (r = -0.222, P < .05). The DNA damage frequencies of the groups formed according to their CAD scores were significantly different from the control group (P < .001) and also each other (P ≤ .01). Comet frequencies and CAD grades were found to be correlated with aging (P < .05). DNA damage frequency and syntax score values were significantly (P < .05) higher in males compared to females. Syntax scores were correlated with aging (r = 0.348, P < .01), ECHO-EF (r = 0.374, P < .001), blood-urea (r = 0.398, P < .001), creatinine (r = 0.433, P < .001), glucose (0.218, P < .05), and HbA1c (r = 0.200, P < .05). Significant correlations were observed between trace elements and demographic values, blood parameters, diseases, angio parameters, ECHO, and ECG parameters. It was observed that the concentrations of trace elements detected in the blood were 93.4% correlated with each other. Lymphocyte DNA damage is a strong biomarker for the atherosclerotic indicator of CAD. Aging is an effective factor both in the DNA damage frequency and CAD risk index. Creatinine and urea are factors that have the power to change the CAD risk index and DNA damage frequency. The higher DNA damage and CAD risk were monitored in males compared to females. The relationship between some biomarkers and blood trace element concentrations showed that further studies are needed to more accurately evaluate the relationship between trace elements, DNA damage frequencies, and CAD.

Development of quantum dot-phthalocyanine integrated G-quadruplex /double-stranded DNA biosensor.

In the present study, the phthalocyanine (Pc) integrated mercaptopropionic acid capped quantum dot (mpa@QD) biosensor has been developed for the quantitative determination of G-quadruplex and double-stranded DNA. The working principle of the developed biosensor platform is based on the quenching of the emission signal of the mpa@QD in the presence of Pc (closed position) and the recovery of the fluorescence signal in the presence of DNA (open position). The parameters affecting biosensor performance, such as Pc type and concentration, were optimized. Since the developed biosensor aimed to determine G-quadruplex and double-stranded DNA in biological samples, the effect of common ions (such as Na+, Mg2+) and serum albumin found in many biological matrices on the biosensor performance were examined. The effect of common ions on biosensor signal was negligible, except Zn2+. The analytical properties of the biosensor, such as linear range, calibration sensitivity, relative standard deviation %, the limit of detection, and quantification, were determined. The limit of detection and quantification values were found 0.055 µM and 0.18 µM for AS1411, 0.061 µM and 0.20 µM for Tel21, 0.038 µM and 0.13 µM for Tel45 and 0.091 µM and 0.30 µM for ctDNA. Several different synthetic samples were prepared. The spiked synthetic samples such as mammalian cell medium were used to evaluate the analytical performance of Pc-mpa@QD. All synthetic samples were prepared with polyethylene glycol, which resembles biological samples' crowded environment.

The synthesis and characterization of iron nanoparticles with lemon peel and its use in magnetic solid phase extraction for trace levels of lead (II).

In this study, a new magnetic solid phase extraction method (MSPE) was developed for the enrichment and separation of trace amount Pb(II) on the magnetic nanoparticles synthesized using lemon peel (Fe3O4-LP). The determination of Pb(II) in the samples was performed with inductively coupled plasma mass spectrometry. The Fe3O4-LP was characterized by scanning electron microscopy, X-ray powder diffractometry, Brunauer-Emmett-Teller surface area analysis, and vibration sample magnetometry. The effect of different parameters such as pH, adsorption and elution time, concentration of eluent and volume and matrix effect on the recovery of Pb(II) was investigated for the MSPE. Considering preconcentration factor, the detection limit value of the proposed method was calculated to be 39 ng/L for Pb (II). The accuracy of the developed method was tested with analysis of the BCR 185 R Bovine Liver and 2976a Mussel Tissue certified reference materials. The results were in good agreement with the certified values.

Determination of sunset yellow, allura red, and fast green using a novel magnetic nanoadsorbent modified with Elaeagnus angustifolia based on magnetic solid-phase extraction by HPLC

Abstract Sunset yellow (SY), allura red (AR) and fast green (FG) are frequently used in commercial food products, although they are considered to be hazardous to public health due to their toxic efficacy and high exposure risk potency. In this study, a new, rapid, and reliable method based on a magnetic solid-phase extraction (MSPE) was developed for the simultaneous determination of SY, AR, and FG. Fe3O4 modified with Elaeagnus angustifolia was used for the first time as an adsorbent (Fe3O4-EA) in MSPE. It was characterized with scanning electron microscopy, Brunauer Emmet Teller surface area analysis and X-ray diffraction. MSPE parameters were optimized in terms of pH, adsorption, and elution time and elution volume. High-performance liquid chromatography was used for dye quantitation. Analytical separation was performed by applying ammonium acetate buffer, acetonitrile, and methanol as the mobile phase to a C18 reverse-phase analytical column. Intraday and inter-day repeatability of the method performed at the concentration of 0.2, 1.0 and 2.0 µg/mL exhibited <8.1% RSD (n=3). The limit of detection values was between 0.05-0.1 µg/mL. The adsorption data of SY, AR and FG on Fe3O4-EA were fitted with the Langmuir model with qmax values of 45.0, 70.4 and 73.0 mg/g, respectively.

Determination of color additive tartrazine (E 102) in food samples after dispersive solid phase extraction with a zirconium-based metal-organic framework (UiO-66(Zr)-(COOH)2).

A new and rapid dispersive solid phase extraction method by using a green-synthesised UiO-66(Zr)-(COOH)2 (Zr-BTeC) adsorbent with body-centred cubic (bcu) topology was developed for determination of tartrazine in food samples. Zr-BTeC was used for the first time as an adsorbent for tartrazine. It was synthesised and characterised by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, Brunauer-Emmett-Teller surface area analysis, and zeta potential measurements. Tartrazine was determined at 405 nm spectrophotometrically. Experimental conditions were optimised in order to achieve quantitative recoveries. The sample acidity was found to be 0.02 mol L-1 HCl. The amount of Zr-BTeC was 10 mg. Both adsorption and elution contact times were only 5 s without the need for vortexing. Elution was with 2 mL of 0.5 mol L-1 NH3. A sample volume of 45 mL was selected as optimum. The adsorption capacity for tartrazine with Zr-BTeC was found to be 185 mg g-1 and the adsorbent was reusable up to 40 cycles. The tartrazine concentrations found by the developed method in food supplements were compared with the results obtained by HPLC method for the same samples. Statistical analysis results showed that there are insignificant differences between the results of the two methods (p = .05). The method was successfully applied to the determination of tartrazine in spiked chewing gums, lemon flavoured icing glaze, and jelly samples.

Characterization of persimmon fruit peel and its biochar for removal of methylene blue from aqueous solutions: thermodynamic, kinetic and isotherm studies.

The persimmon fruit peel (PFP) and its biochar (PFP-P) were evaluated for removal of methylene blue (MB) from aqueous solutions and characterized in detail. The pyrolysis of the PFP improved carbon content, surface area, and surface electronegativity of the biochar produced. The effect of initial solution pH, initial MB concentration, contact time, and temperature on the biosorption efficiency of MB on the PFP was investigated through the biosorption experiments in a batch system. The PFP showed higher biosorption removal efficiency than PFP-P due to the existence of hydroxyl and carboxyl functional groups. The maximum biosorption capacity of the PFP was found using 2 g/L of the adsorbent, at a contact time of 180 min and pH of 7. The adsorption kinetics and equilibrium isotherms were well represented by the pseudo-second-order model and the Langmuir model, respectively. The maximum biosorption capacity obtained from the Langmuir isotherm model was 303 mg g-1. Also, the PFP showed an efficient removal efficiency for removal of MB in tap water, seawater, and river water. The high MB biosorption capacity of PFP can be a promising alternative for cationic dye removal at neutral pH.

Solid-Phase Extraction Method by Magnetic Nanoparticles Functionalized with Murexide for Trace U(VI) from Sea Water Prior to Spectrophotometric Determination.

In this study, magnetic nanoparticles (Fe3O4/SiO2/APTES) functionalized with murexide were used for the determination of uranium(VI) in sea water by spectrophotometric method in perchloric acid medium using Arsenazo-III as chromogenic reagent. The effects of some analytical parameters, such as pH, contact time, and eluent volume, on the recovery of uranium(VI) were examined in synthetic sea water. The optimum conditions were achieved with a 15 min adsorption time and 2 min elution time with 1 mL of 5 mol L-1 HClO4 at pH of 6.5 and 25 mg of the magnetic sorbent. The linear range, detection limit, and precision (as RSD%) of the method were found to be 0.02-4.0 mg L-1, 0.001 mg L-1 and 3.0%, respectively. The proposed method is simple, rapid, and cost-effective for the determination of U(VI) in sea water, with a total analysis time of approximately 30 min. The adsorption isotherm was well fitted to the Langmuir model, with a correlation coefficient of 0.9997 and Qmax value was found to be 77.51 mg g-1. The magnetic sorbent was successfully used for the rapid determination of trace quantities of U(VI) ions in different sea waters, and satisfactory results were obtained.

Triethylamine-assisted Mg(OH)2 coprecipitation/preconcentration for determination of trace metals and rare earth elements in seawater by inductively coupled plasma mass spectrometry (ICP-MS).

In this paper, we report an improved magnesium hydroxide, Mg(OH)2, coprecipitation method for the determination of 16 trace elements (Al, V, Cr, Mn, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Sb, Sn and Pb) and 18 rare earth elements (REEs), including Sc, Y, U and Th in seawater and estuarine water samples. The procedure involves coprecipitation of the trace elements and REEs on Mg(OH)2 upon addition of a small volume of triethylamine (TEA) followed by analysis of the dissolved pellet solutions by inductively coupled plasma mass spectrometry (ICP-MS). Three-step sequential coprecipitation was carried out on 10 mL aliquots of seawater to eliminate the matrix ions and to preconcentrate the analytes of interest into a 1 mL final volume. Spike recoveries varied from 85% (Th) to 105% (Y). Calcium (Ca), sodium (Na) and potassium (K) matrices were virtually eliminated from the analysis solutions. Collision reaction interface (CRI) technology utilizing H2 and He gases was employed to determine its effectiveness in removing the spectral interferences originating from the residual Mg matrix, TEA and plasma gases. H2 was more effective than He in reducing spectral interferences from TEA and plasma gases. Limits of detection (LODs) ranged from 0.01 ng L-1 (Ho) to 72 ng L-1 (Al). The method was validated by using certified seawater (CASS-4) and estuarine water (SLEW-3) reference materials. Precision for five (n = 5) replicate measurements were between 1.2% (Pr) and 18% (Lu). Fe, Pb, Sn, and Zn impurities in TEA were significant in comparison to the levels in CASS-4 and SLEW-3, while relatively high background signals impacted determinations of low levels of Sc and Th. The effects of these hurdles on precision and accuracy were alleviated by measuring these elements in spiked CASS-4 and SLEW-3.

Use of Water Soluble and Phosphorescent MPA-capped CdTe Quantum Dots for the Detection of Urea.

OBJECTIVES: To describe a method for the determination of urea in blood serum using urease enzyme and 3-MPA-capped CdTe quantum dots. MATERIALS AND METHODS: The method is based on the increase in pH of the solution as a result of the reaction between urea and urease, which causes an increase in the phosphorescence signal of MPA-CdTe quantum dots in the pH range of 2.5-5.0. Under the optimum conditions, the linear range of urea was 0.016-0.16 mM (1-10 mg/L) and the limit of detection based on 3 s/b was calculated as 0.003 mM (0.17 mg/L). The relative standard deviation was calculated as 3.4% at 4 mg/L urea concentration (n=7). RESULTS: The method was applied to human serum samples. The same samples were analyzed by an independent laboratory and the results were not statistically different, at 95% confidence level (F test). CONCLUSION: The proposed method does not need sample pretreatment, is simple, selective, and cost-effective for the determination of urea in serum samples.