Determination of exposure to major iodide ion uptake inhibitors through drinking waters.

Goiter, abnormal enlargement of the thyroid gland, is a significant worldwide public health problem. Iodine deficiency is known as the most common cause. Iodine is actively transported as iodide ion (I-) using Sodium Iodide Symporter (NIS) and sufficient blocking of I- transportation prevents the synthesis of thyroid hormones. The transportation can be blocked by some polyatomic anions known as I- uptake inhibitors. Perchlorate (ClO4-), thiocyanate (SCN-) and nitrate (NO3-) are reported as the major I- uptake inhibitors and exposure could be through various routes. Drinking water is an important exposure route. Since water is essential to sustain life, drinking water safety is very important for the protection of public health. However, as a result of natural and human-based processes, water can be contaminated and contamination of drinking water is a global food safety problem due to causing significant health and environmental problemsIn that context, this study aims to determine exposure levels to I- uptake inhibitors that arise from drinking waters at five different districts in Antalya, Turkey. Collected water samples contained NO3- and ClO4- in the range of 0.86-47.42 mg/L and

A novel technique for the reduction of pesticide residues by a combination of low-intensity electrical current and ultrasound applications: A study on lettuce samples.

In this study, effects of low-intensity electrical currents (200, 800 and 1400 mA), ultrasound frequencies (24 and 40 kHz) and their combinations were applied at the duration period of 2, 4, 6, 8, and 10 min for the degradation of captan, thiamethoxam and metalaxyl residues in lettuce samples. Residues of the pesticides were determined by gas chromatography with tandem mass spectrometry and electron capture detector. The results indicated that the combination of low-intensity electrical current and ultrasound was found to be effective for the reduction of the pesticides. The most effective combination was obtained to be current of 1400 mA and ultrasound frequency of 24 kHz at 10 min. Under this circumstance, 92.57, 81.99 and 93.09% of captan, thiamethoxam and metalaxyl residues were decreased, respectively. The findings suggest that the combination of low-intensity electrical current and ultrasound applications has an important potential for the degradation of pesticide residues.

Reduction of pesticide residues from tomatoes by low intensity electrical current and ultrasound applications.

In this study, effects of low intensity electrical current (EC) and ultrasound (US) treatments on the reduction of some important pesticides (captan, thiamethoxam and metalaxyl) residues in tomato samples were investigated. Three different currents (200, 800 and 1400mA) of EC were applied at various time intervals (2, 4, 6, 8 and 10min). Two kinds of US treatments including ultrasonic bath (UB) at 40kHz and ultrasonic probe (UP) at 24kHz were tested for the determination of US effectiveness. In addition, synergistic effects of US on EC treatments were evaluated. The most effective conditions for reduction of captan, thiamethoxam and metalaxyl residues were 1400mA+40kHz, 800mA+24kHz and 1400mA+24kHz, respectively. The residues of captan, thiamethoxam and metalaxyl were reduced in the order of 94.24%, 69.80% and 95.06% by using these combinations. EC and US strategies can be considered as effective treatments in industrial scale in order to remove the pesticide residues from vegetables.

Monitoring of metallic contaminants in energy drinks using ICP-MS.

In this study, an improved method was validated for the determination of some metallic contaminants (arsenic (As), chromium (Cr), cadmium (Cd), lead (Pb), iron (Fe), nickel (Ni), copper (Cu), Mn, and antimony (Sb)) in energy drinks using inductive coupled plasma mass spectrometry (ICP-MS). The validation procedure was applied for the evaluation of linearity, repeatability, recovery, limit of detection, and quantification. In addition, to verify the trueness of the method, it was participated in an interlaboratory proficiency test for heavy metals in soft drink organized by the LGC (Laboratory of the Government Chemist) Standard. Validated method was used to monitor for the determination of metallic contaminants in commercial energy drink samples. Concentrations of As, Cr, Cd, Pb, Fe, Ni, Cu, Mn, and Sb in the samples were found in the ranges of 0.76-6.73, 13.25-100.96, 0.16-2.11, 9.33-28.96, 334.77-937.12, 35.98-303.97, 23.67-60.48, 5.45-489.93, and 0.01-0.42 µg L-1, respectively. The results were compared with the provisional guideline or parametric values of the elements for drinking waters set by the WHO (World Health Organization) and EC (European Commission). As, Cd, Cu, and Sb did not exceed the WHO and EC provisional guideline or parametric values. However, the other elements (Cr, Pb, Fe, Ni, and Mn) were found to be higher than their relevant limits at various levels.

Evaluation of heavy metal risk potential in Bogacayi River water (Antalya, Turkey).

This study analyzed 25 river water samples collected from the Bogacayi River in Antalya, Turkey, to evaluate the potential risk of pollution by heavy metals. Concentrations of As, Ba, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Se, Sr, and V were determined by inductively coupled plasma mass spectrometry (ICP-MS). The method was validated prior to analysis in terms of linearity, limit of detection (LOD), limit of quantification (LOQ), and recovery. In addition, a certified standard (SPS-SW2 surface water) was used to verify method trueness. Method validation data and results obtained from the certified material suggested that the method could be applied to determine elemental compositions of the samples. Although various concentrations of As, Ba, Cd, Cr, Cu, Mn, Ni, Pb, and Sr were found in the samples, no Hg, V, Co, and Se concentrations were found. The highest concentration of Pb, Cd, and As was found in the samples from the 22nd, 16th, and 5th sampling stations, respectively. Concentrations of the studied elements were aligned from high to low as Sr > Ba > Ni > Cr > Cu > Mn > Pb > As > Cd. To evaluate the risk potential of metallic pollution, the data were used to calculate the heavy metal pollution index (HPI). The HPI values were found to be in the range from 7.81 to 43.97 (mean 25.48). Samples from upstream seemed to show lower risk potentials (<15) than those from downstream (>30); however, all HPI values were lower than 100, which is the critical HPI value for drinking safety.

Determination of major sodium iodide symporter (NIS) inhibitors in drinking waters using ion chromatography with conductivity detector.

Goiter is an important health problem all over the world and iodine deficiency is its most common cause. Perchlorate, thiocyanate and nitrate (called as major NIS inhibitors) are known to competitively inhibit iodide uptake by the thyroid gland and thus, human exposure to major NIS inhibitors is a public health concern. In this study, an ion chromatographic method for the determination of most common NIS inhibitor ions in drinking waters was developed and validated. This is the first study where an analytical method is used for the determination of major NIS inhibitors in drinking water by an ion chromatography system in a single run. Chromatographic separations were achieved with an anion-exchange column and separated ions were identified by a conductivity detector. The method was found to be selective, linear, precise accurate and true for all of interested ions. The limits of the detections (LOD) were estimated at 0.003, 0.004 and 0.025mgL(-1) for perchlorate, thiocyanate and nitrate, respectively. Possible interference ions in drinking waters were examined for the best separation of NIS inhibitors. The excellent method validation data and proficiency test result (Z-score for nitrate: -0.1) of the FAPAS(®) suggested that the developed method could be applied for determination of NIS inhibitor residues in drinking waters. To evaluate the usefulness of the method, 75 drinking water samples from Antalya/Turkey were analyzed for NIS inhibitors. Perchlorate concentrations in the samples ranged from not detected (less than LOD) to 0.07±0.02mgL(-1) and the range of nitrate concentrations were found to be 3.60±0.01mgL(-1) and 47.42±0.40mgL(-1). No thiocyanate residues were detected in tested drinking water samples.

Elution of monomer from different bulk fill dental composite resins.

OBJECTIVE: The purpose of this study was to evaluate the elution of Bis-GMA, TEGDMA, HEMA, and Bis-EMA monomers from six bulk fill composite resins over four different time periods, using HPLC. METHODS: Six different composite resin materials were used in the present study: Tetric Evo Ceram Bulk Fill (Ivoclar Vivadent, Amherst, NY), X-tra Fill (VOCO, Cuxhaven, Germany), Sonic Fill (Kerr, Orange, CA, USA), Filtek Bulk Fill (3M ESPE Dental Product, St. Paul, MN), SDR (Dentsply, Konstanz, Germany), EQUIA (GC America INC, Alsip, IL). The samples (4mm thickness, 5mm diameter) were prepared and polymerized for 20s with a light emitted diode unit. After fabrication, each sample was immediately immersed in 75wt% ethanol/water solution used as extraction fluid and stored in the amber colored bottles at room temperature. Ethanol/water samples were taken (0.5mL) at predefined time intervals:10m (T1), 1h (T2), 24h (T3) and 30 days (T4). These samples were analyzed by HPLC. The obtained data were analyzed with one-way ANOVA and Tukey HSD at significance level of p<0.05. RESULTS: Amount of eluted Bis-EMA and Bis-GMA from Tetric Evo Ceram Bulk Fill and amount of eluted TEGDMA and HEMA from X-tra Fill higher than others composites (p<0.05). SIGNIFICANCE: Residual monomers were eluted from bulk fill composite resins in all time periods and the amount of eluted monomers was increased with time.

An eco-friendly, quick and cost-effective method for the quantification of acrylamide in cereal-based baby foods.

BACKGROUND: The presence of acrylamide in cereal-based baby foods is a matter of great concern owing to its possible health effects. Derivatization followed by gas chromatography/mass spectrometry (GC/MS) is one of the most common methods to quantify acrylamide. However, it requires the use of toxic chemicals and is time-consuming. The aim of this study was to develop an eco-friendly, rapid and inexpensive method for the determination of acrylamide in cereal-based baby foods. RESULTS: The method involves defatting with n-hexane, extraction into water, precipitation of proteins, bromination, extraction into ethyl acetate and injection into a GC/MS system. The effects of defatting, precipitation, treatment with triethylamine, addition of internal standard and column selection were reviewed. A flow chart for acrylamide analysis was prepared. To evaluate the applicability of the method, 62 different cereal-based baby foods were analyzed. The levels of acrylamide ranged from not detected (below the limit of detection) to 660 µg kg(-1). CONCLUSION: The method is more eco-friendly and less expensive because it consumes very little solvent relative to other methods using bromine solutions and ethyl acetate. In addition, sample pre-treatment requires no solid phase extraction or concentration steps. The method is recommended for the determination of trace acrylamide in complex cereal-based baby food products.

Acrylamide exposure among Turkish toddlers from selected cereal-based baby food samples.

In this study, acrylamide exposure from selected cereal-based baby food samples was investigated among toddlers aged 1-3 years in Turkey. The study contained three steps. The first step was collecting food consumption data and toddlers' physical properties, such as gender, age and body weight, using a questionnaire given to parents by a trained interviewer between January and March 2012. The second step was determining the acrylamide levels in food samples that were reported on by the parents in the questionnaire, using a gas chromatography-mass spectrometry (GC-MS) method. The last step was combining the determined acrylamide levels in selected food samples with individual food consumption and body weight data using a deterministic approach to estimate the acrylamide exposure levels. The mean acrylamide levels of baby biscuits, breads, baby bread-rusks, crackers, biscuits, breakfast cereals and powdered cereal-based baby foods were 153, 225, 121, 604, 495, 290 and 36 µg/kg, respectively. The minimum, mean and maximum acrylamide exposures were estimated to be 0.06, 1.43 and 6.41 µg/kg BW per day, respectively. The foods that contributed to acrylamide exposure were aligned from high to low as bread, crackers, biscuits, baby biscuits, powdered cereal-based baby foods, baby bread-rusks and breakfast cereals.