Development of rapid, sensitive and selective fluorimetric method for determination of 1-naphthalene acetic acid in cucumber by using magnetite-molecularly imprinted polymer.

In this study, a novel method based on the determination of 1-naphthalene acetic acid with the usage of magnetite-molecularly imprinted polymer prior to fluorimetric detection has been developed. Magnetite-molecularly imprinted polymer has been used for the first time as selective adsorbent for the determination of 1-naphthalene acetic acid. The adsorption capacity of the synthesized polymer was found to be 2.18 ±â€¯0.36 mg g-1 (n = 3). Limit of detection (LOD) and limit of quantification (LOQ) of the method were found to be 0.75 and 2.50 µg L-1, respectively. Linearity of the calibration graph for the proposed method was observed within the range of 20-700 µg L-1. The proposed method seems to be rapid where the detection procedure for 1-naphthalene acetic acid can be completed within a total time of 1 h. The same imprinted polymer can be used for the determination of 1-naphthalene acetic acid with quantitative sorption and recovery values repeatedly for at least ten times. The effects of some potential organic interferences were investigated. Proposed method has been successfully applied to determine 1-naphthalene acetic acid in cucumber, where the recoveries of the spiked samples were found to be in the range of 93.7-104.5%. Characterization of the synthesized polymer was also evaluated. By combining the high capacity, cheapness, reusability and selectivity of the magnetic adsorbent with the dynamic calibration range, rapidity, simplicity, and sensitivity of fluorimetry, the proposed method seems to be an ideal method for the determination of trace levels of 1-naphthalene acetic acid.

Highly sensitive and selective method for the rapid determination and preconcentration of haloperidol by using a magnetite-molecularly imprinted polymer.

A sensitive and selective method based on the determination of haloperidol with the usage of magnetite-molecularly imprinted polymer and high-resolution liquid chromatography has been developed. This novel method is rapid as the detection procedure for haloperidol can be completed within a total time of 1 h. The same imprinted polymer can be used for the determination of haloperidol at least 20 times. The proposed method has been succesfully applied to synthetic urine and serum samples and the recoveries of the spiked samples were in the range of 94.7-100.7%. The limit of detection and limit of quantification of the method were 2.25 and 7.50 µg/L, respectively. Linearity of the calibration graph was observed within the range of 10-250 µg/L. By combining the high capacity, high selectivity, and reusability of the magnetic adsorbent with the dynamic calibration range, high sensitivity and high resolution of liquid chromatography with quadrupole time-of-flight mass spectrometry, the proposed method is an ideal method for the determination and preconcentration of trace levels of haloperidol. A magnetite-molecularly imprinted polymer has been used for the first time as a selective adsorbent for the determination of haloperidol.

Sandpaper Wastes as Adsorbent for the Removal of Brilliant Green and Malachite Green Dye.

Sandpaper wastes were used as adsorbent after pyrolysis at 500 °C and calcination at 800 °C for the removal of brilliant green and malachite green cationic dye from an aqueous solution. The effects of the pH, the adsorbent dose, the contact time, and the initial dye concentration on the removal efficiencies were investigated. The isotherm studies were conducted by using the Langmuir, Freundlich, and Dubinin-Radushkevich models, and thermodynamic studies were also performed. The adsorption of the Brilliant green and malachite green were found to comply with the Langmuir isotherm model and the Freundlich isotherm model, respectively. The thermodynamic studies showed that the adsorption of dyes were endothermic. The E values obtained from the Dubinin-Radushkevich isotherm showed that the adsorption mechanism was chemical in nature. Furthermore, the three kinetic models (pseudo first-order, pseudo second-order, and intraparticle diffusion) were investigated. It was found that the pseudo second-order kinetic model fitted well for adsorption of dyes.

Selective and sensitive fluorimetric determination of carbendazim in apple and orange after preconcentration with magnetite-molecularly imprinted polymer.

In this study, magnetite-molecularly imprinted polymer has been used for the first time as selective adsorbent before the fluorimetric determination of carbendazim. Adsorption capacity of the magnetite-molecularly imprinted polymer was found to be 2.31±0.63mgg-1 (n=3). Limit of detection (LOD) and limit of quantification (LOQ) of the method were found to be 2.3 and 7.8µgL-1, respectively. Calibration graph was linear in the range of 10-1000µgL-1. Rapidity is an important advantage of the method where re-binding and recovery processes of carbendazim can be completed within an hour. The same imprinted polymer can be used for the determination of carbendazim without any capacity loss repeatedly for at least ten times. Proposed method has been successfully applied to determine carbendazim residues in apple and orange, where the recoveries of the spiked samples were found to be in the range of 95.7-103%. Characterization of the adsorbent and the effects of some potential interferences were also evaluated. With the reasonably high capacity and reusability of the adsorbent, dynamic calibration range, rapidity, simplicity, cost-effectiveness and with suitable LOD and LOQ, the proposed method is an ideal method for the determination of carbendazim.

Determination of essential and non-essential elements in various tea leaves and tea infusions consumed in Turkey.

Tea is one of the most popular beverages in the world. Thus, the chemical components in tea are of great interest, especially in relation to health. In this study, 12 tea samples (10 black, 1 white and 1 green) and 5 herbal tea samples were purchased from supermarkets in Izmir, Turkey. Sample preparation has been performed using wet and microwave digestion procedures. The elemental content (Fe, Zn, Cu, Mn, Ni, Na and K) in the digests and infusions has been analysed. Generally, elemental contents in tea leaves were found to be higher than those in tea infusions. The accuracy of the method was checked and confirmed by standard reference material analyses. The comparison of wet and microwave digestion has not shown significantly different results. Therefore, the microwave digestion procedure was preferred because it is less laborious. The elemental intake related to tea consumption has also been studied.

Determination of arsenic leaching from glazed and non-glazed Turkish traditional earthenware.

Glazed and non-glazed earthenware is traditionally and widely used in Turkey and most of the Mediterranean and the Middle East countries for cooking and conservation of foodstuff. Acid-leaching tests have been carried out to determine whether the use of glazed and non-glazed earthenware may constitute a human health hazard risk to the consumers. Earthenware was leached with 4% acetic acid and 1% citric acid solutions, and arsenic in the leachates was measured using hydride generation atomic absorption spectrometry. Arsenic concentrations in the leach solution of non-glazed potteries varied from 30.9 to 800 µg L⁻¹, while the glazed potteries varied generally from below the limit of detection (0.5 µg L⁻¹) to 30.6 µg L⁻¹, but in one poorly glazed series it reached to 110 µg L⁻¹. Therefore, the risk of arsenic poisoning by poorly glazed and non-glazed potteries is high enough to be of concern. It appears that this is the first study reporting arsenic release from earthenware into food.

Highly sensitive sensing of zinc(II) by development and characterization of a PVC-based fluorescent chemical sensor.

A sensor membrane with excellent performance based on 1-methyl-1-phenyl-3-[1-hydroxyimino-2-(succinimido)ethyl]cyclobutane has been developed for the determination of zinc(II) ions. The sensing membrane is capable of determining zinc(II) with an outstanding high selectivity over a dynamic range between 8.0×10(-8) and 1.6×10(-4) mol L(-1) with a limit of detection of 2.5×10(-8) mol L(-1) (1.6 µg L(-1)). It can be easily and completely regenerated by using 0.1 mol L(-1) EDTA solution. The optical sensor developed here was found to be stable, cost effective, easy to prepare, and has unique selectivity towards Zn(2+) ion with respect to common metal ions. The proposed sensor was then applied for the determination of zinc in tap water and hair samples with satisfactory results.