Monitoring of Essential and Toxic Elements in Multivitamin/Mineral Effervescent Tablet Supplements and Safety Assessment.

Multivitamin/mineral (MVM) supplements are the most commonly utilized dietary supplements by many populations. However, there is a severe concern about their adverse effects due to elemental impurities. In the present study, it was aimed to determine the levels of 11 elemental impurities (Cd, Pb, As, Hg, Co, V, Ni, Se, Mo, Cu, and Cr) by inductively coupled plasma-mass spectrometry (ICP-MS) and evaluate the human health risk associated with the consumption of 33 MVM effervescent tablet supplements available in Turkey. The precision of the method in terms of relative standard deviation (RSD) was less than 4.6%. The accuracy of the method was tested with recovery experiments, and the results ranged between 86 and 107%. The impurity levels for Cd, Pb, As, Co, V, Ni, Se, Mo, Cu, and Cr were found between 0.011-0.050, 0.025-0.098, 0.018-0.056, 0.010-0.626, 0.027-0.290, 0.026-1.65, 1.92-21.83, 0.034-34.09, 0.140-183.9, and 0.033-13.10 µg/g, respectively, and Hg was not detected in any sample. The calculated concentrations for elemental impurities complied with EMA and USP guidelines, except one supplement for Se (21.83 µg/g) with a permitted limit of 15 µg/g. The hazard quotient (HQ) and hazard index (HI) levels were below 1 for all samples within the ranges of 3.4 × 10-1-1.4 × 10-6 for HQ and 7.8 × 10-1-1.4 × 10-6 for HI indicating that there is no risk for consumption. The carcinogenic risk (CR) of As was between 1.7 × 10-6 and 5.9 × 10-6, below the threshold value of 1 × 10-4. The results showed that there is no risk to human health.

GC-MS Based Metabolomics Analysis to Evaluate Short-Term Effect of Tumor Removal on Patients with Early-Stage Breast Cancer.

In this study, it was aimed to demonstrate the short-term effect of breast cancer surgery and tumor removal on the metabolomic profiles of patients with early-stage breast cancer. This cohort consisted of 18 early-stage breast carcinoma patients who had breast cancer surgery to remove tumor and surrounding tissues. The blood samples obtained preoperatively and 24 h after surgery were used in this investigation. Gas chromatography-mass spectrometry (GC-MS) based metabolomic analysis was performed to determine the metabolites. The GC-MS-based metabolomics profile enabled the identification of 162 metabolites in the plasma samples. Postoperatively, glyceric acid, phosphoric acid, O-phosphocolamine, 2-hydroxyethyliminodiacetic acid, N-acetyl-D-mannosamine, N-acetyl-5-hydroxytryptamine, methyl stearate, methyl oleate, iminodiacetic acid, glycerol 1-phosphate, ß-glycerol phosphate and aspartic acid were found to be significantly increased (P < 0.05 for all), whereas saccharic acid, leucrose, gluconic acid, citramalic acid and acetol were significantly decreased (P < 0.05 for all). Breast cancer surgery and tumor removal has an impact on the metabolomic profiles of patients with early-stage breast cancer. These findings can be used for understanding the pathogenesis of breast cancer biology and screening the success of the surgery.

A rapid on-line non-chromatographic hydride generation atomic fluorescence spectrometry technique for speciation of inorganic arsenic in drinking water.

A rapid on-line non-chromatographic hydride generation atomic fluorescence spectrometry is described and determination of inorganic arsenic (iAs (III) and iAs (V)) species is achieved within a single run. Thioglycolic acid (TGA) was used for on-line pre-reduction of iAs (V) and quantification of arsenic species was accomplished via calibration with one As form; as iAs (III). Samples and calibration standards were prepared in Tris buffer (pH:7.2) for selective hydride generation and without on-line pre-reduction, iAs (V) signal was negligible up to 150 ng ml-1. The limit of detection (LOD) values for iAs (III) and iAs (V) were 27 pg ml-1 and 36 pg ml-1, respectively. Recovery studies were performed, certified reference material (TMDA-61) was used to test the accuracy of the method and the results were in good agreement. iAs (V) was the main form in all water samples whereas iAs (III) concentration was

Pilot study of environmental monitoring of Konya region near abandoned mercury mine in Turkey.

Abandoned mines are an important global concern and continue to pose potential threats to human health including environmental damage/s. There is not any specific regulation for mining wastes in Turkey and this situation puts the mining wastes into the dangerous category. Therefore, this study focuses on the environmental effects of the abandoned mercury mines. To demonstrate environmental mercury contamination, fish samples were collected from two different regions which were contaminated and uncontaminated region. As a biomarker of environmental exposure the levels of Hg in fish samples were measured by Cold Vapor-Atomic Absorption Spectrometry (CVAAS). In fish samples, the levels of Hg were 0.504 ± 0.475 (mg/kg) (Mean ± SD) in Group 1 and 0.04 ± 0.054 (mg/kg) (Mean ± SD) in Group 2. Our data suggested that although mercury mine was closed long time ago, mining waste is still a problem and continues to contaminate the environment.

Determination of nitrogen mustard hydrolysis products in rat urine samples using GC-MS.

A gas chromatographic-mass spectrometric method was developed, validated and demonstrated by measuring the levels of nitrogen mustard hydrolysis products in the urine collected from dosed rats. The recovery values for trimethylsilyl derivatives of EDEA and MDEA are between 82-95% and 88-112%, respectively. In vivo studies performed by using three different doses (0.5 mg/kg, 1.0 mg/kg, and 2.0 mg/kg) of HN2 base of nitrogen mustard. MDEA concentrations were between 43.1-232.2 ng/mL. The limit of detection (S/N = 3) values are 2.5 ng/mL and 1.6 ng/mL for EDEA and MDEA, respectively, and the precision of the method in terms of RSD is between 5-8%.

Selenium effects on arsenic cytotoxicity and protein phosphorylation in human kidney cells using chip-based nanoLC-MS/MS.

Although arsenic toxicity is well known, little is known of how it exerts its effects at the proteome level. Protein phosphorylation is an important post-translational modification in the regulation of cell signaling. Despite the importance of protein phosphorylation, the identification and characterization of phosphorylated proteins, as influenced by interaction between arsenic and selenium species have not been fully studied. The aim of this study is to identify phosphorylation in arsenic toxified cells, with and without selenium present. Here, we identify the phosphorylated proteins related to post translational modifications (PTMs) after inorganic arsenic (iAs) and selenomethionine (SeMet) were inoculated together with HEK293 human kidney cells. In this study, using TiO(2)-based nanoLC-phosphochip® coupled to ESI-MS we observed phosphorylated peptide enrichment and significant reduction in sample complexity. The identification of phosphorylated proteins in highly complex digests of cell lysate were markedly different with As toxification only, or when in the presence of SeMet. Several phosphorylation sites and proteins are identified using Spectrum Mill and Mascot protein data base search engines. Cytotoxicity studies showed that SeMet significantly reduces the cytotoxic effect of iAs in HEK293 cells, while inorganic selenium did not.

Arsenic-induced protein phosphorylation changes in HeLa cells.

Arsenic is well documented as a chemotherapeutic agent capable of inducing cell death while at the same time is considered a human carcinogen and an environmental contaminant. Although arsenic toxicity is well known and has formed an impressive literature over the time, little is known about how its effects are exerted at the proteome level. Protein phosphorylation is an important post-translational modification involved in the regulation of cell signaling and likely is altered by arsenic treatment. Despite the importance of phosphorylation for many regulatory processes in cells, the identification and characterization of phosphorylation, as effected by arsenic through mass spectrometric detection, are not fully studied. Here, we identify phosphorylated proteins, which are related to post-translational modifications after phenylarsine oxide (PAO) inoculation to HeLa cells. PAO was chosen because of its high cytotoxicity, measured earlier in these labs. In this study, size exclusion chromatography coupled to inductively coupled plasma mass spectrometry (SEC-ICP-MS) is used to establish several molecular weight fractions with phosphorylated proteins by monitoring (31)P signal vs. time via ICP-MS. SEC-ICP-MS fractions are collected and then separated by the nano-LC-CHIP/ITMS system for peptide determination. Spectrum Mill and MASCOT protein database search engines are used for protein identification. Several phosphorylation sites and proteins related to post-translational modifications are also identified.

Determination of tin by in situ trapping of stannane on a resistively heated iridium treated tungsten coil surface and interference studies.

A novel method was developed for the in situ trapping of stannane on an iridium-coated tungsten coil. Coating the tungsten coil with iridium has significantly improved the sensitivity. The tungsten coil can either be used as an on-line atomizer or as a trapping surface. The interference effect of some hydride-forming elements such as, As(III), Se(IV), Te(IV), Sb(III) was investigated. The interference effect of Sb(III) and Se(IV) could not be completely eliminated using in situ trapping mode but the magnitude of their interferences was reduced significantly when compared to quartz T-tube atomizer. The limit of detection with iridium-coated tungsten coil for a 60s trapping period (sample volume 6 ml) was found to be 0.065 ng ml(-1) and the calibration was linear over the range of 0.5-4.0 ng ml(-1). The precision of the analytical method was determined to be 2.2% RSD (n=11) for 1.0 ng ml(-1) Sn concentration. Analytical performance of the proposed method was checked by analyzing tap water, spring water and mineral water samples for Sn. The accuracy of the method was tested with two different certified reference materials; fortified water TMDA 61 (NWRI) and Dogfish Liver DOLT-3 (NRC). The results were in a good agreement with the certified values at 95% confidence level.