Ayhan Filazi

Determination of melamine in milk and dairy products by high performance liquid chromatography

A simple, precise, accurate, and validated reverse-phase HPLC method was developed for the determination of melamine in milk (pasteurized and UHT milk) and dairy products (powdered infant formula, fruit yogurt, soft cheese, and milk powder). Following extraction with acetonitrile:water (50:50, vol/vol), samples were purified by filter (0.45 μm), separated on a Nucleosil C8 column (4.6 mm × 250 mm, 3 μm) with acetonitrile:10 mmol/L sodium L-octane sulfonate (pH 3.1; 15:85, vol/vol) as mobile phase at a flow rate of 1 mL/min, and determined by a photodiode array detector. A linear calibration curve was obtained in the concentration range from 0.05 to 5 mg/kg. Milk and dairy products were fortified with melamine at 4 levels producing average recovery yields of 95 to 109%. The limits of detection and quantification of melamine were 35 to 110 and 105 to 340 μg/kg, respectively. The method was then used to analyze 300 samples of milk and dairy products purchased from major retailers in Turkey. Melamine was not found in infant formulas and pasteurized UHT milk, whereas 2% of cheese, 8% of milk powder, and 44% of yogurt samples contained melamine at the 121, 694±146, and 294±98 μg/kg levels, respectively. These findings were below the limits set by the Codex Alimentarius Commission and European Union legislation. This is the first study to confirm the existence of melamine in milk and dairy products in Turkey. Consumption of foods containing these low levels of melamine does not constitute a health risk for consumers.

Metal concentrations in tissues of the Black Sea fish Mugil auratus from Sinop-Icliman, Turkey

Levels of five heavy metals [copper (Cu), lead (Pb), cadmium (Cd), chromium (Cr) and nickel (Ni)] were evaluated in liver and muscle tissues of fish (Mugil auratus) collected from the Black Sea at Sinop-Icliman, Turkey. Sampling and analysis methods are described. Variations of heavy metal concentrations with seasons are discussed. Cr and Ni concentrations were below the limits of detection (<0.05 and 0.1 ug/g dry weight) in all tissues and seasons. Cu, Pb and Cd were detected within these limits, as mg/kg dry weight, in liver tissue: 0.49-1.30, 0.60-1.21 and 0.15-0.50, and in muscle tissue: 0.30-1.00, 0.57-1.12 and 0.10-0.40, respectively. Cu, Pb and Cd concentrations in these tissues were elevated and the highest heavy metal concentrations were found in the liver. While Cu, Pb and Cd concentrations were highest in fish tissues collected in August 2000, the lowest concentrations of these metals were observed in fish tissues collected in May 2000. Pb had the highest level observed in fish tissues. According to the Turkish Food Codex Regulations residue limits, the cadmium level determined in fish tissues was high (0.1 mg/g) and the lead level, especially in liver tissue, was high in August (1 mg/ g), while other metals (Cu, Cr and Ni) were within the maximum residue limits.

The influence of amitraz on biochemical parameters in mice.

In this study, the effect of amitraz on biochemical parameters of mice was studied. Mice were given amitraz by gavage at 15 or 45 mg/kg body weight. Since the drug was diluted with dimethylsulphoxide (DMSO), it was administered to another experimental animal group in order to determine its own effects on biochemical parameters. Following drug administration, 48 hours passed to let hepatic lesions develop and after that 1 mL of blood was taken from each mouse. They were killed by ether euthanasia for histopathological examination. The result of the analyses revealed that amitraz had no effect on serum glucose concentration, whereas DMSO led to a significant decrease in blood sugar concentration. Increase in urea, phosphorous, aspartate transaminase and alanine amino transferase values were observed only in the group given 45 mg/kg body weight amitraz. A decrease in creatinine and alkaline phosphatase concentrations was observed in all groups. No differences were observed in serum calcium and bilirubin concentrations. No pathological changes were detected in the kidneys and livers. It was concluded that, even in asymptomatic amitraz toxicity cases, adverse effects on kidney and liver functions were likely to develop.

Residues of gentamicin in eggs following medication of laying hens.

1. Gentamicin was injected subcutaneously and intramuscularly into 5 groups of 10 laying hens and its concentration was determined in albumen, yolk and whole egg. 2. Groups 1 and 3 were intramuscularly injected with doses of 10 and 25 mg/kg while groups 2, 4 and 5 were subcutaneously injected with doses of 10, 25 and 50 mg/kg, respectively. 3. The final gentamicin concentration in albumen was measured on d 3 for groups 1 and 2; on d 4 for groups 3 and 4, and on d 5 for group 5. Concentrations in yolk and whole egg were measured on d 7, 10 and 12. 4. Gentamicin recovery was as follows: 2% in groups 1 and 2, 2·5% in groups 3 and 4, and 3% in group 5. 5. Most of the residue (∼90%) was recovered from the yolk.

Effects of Polychlorinated Biphenyls 28, 30 and 118 on Bovine Spermatozoa In Vitro

Decline of semen quality due to endocrine-disrupting chemicals is of concern globally. Among endocrine disrupting chemicals (EDC), Polychlorinated biphenyls (PCB) are associated with reduced semen quality in various epidemiological studies. In this study, we evaluated the direct effects of selected PCBs (28, 30 and 118) on fresh spermatozoa of Simmetial bulls aged 2-4 years were evaluated in vitro by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and computer assisted semen analysis (CASA) (SCA; Microptics) analysis. IC50 values were found as 8.45, 5.45 and 9.55 ng/ml for PCB 28, 30 and 118, respectively. Total motility, progressive motility and viability decreased dependent on dose and duration of exposure (0, 2, 4 h). Total motility at IC50 doses decreased the most in PCB 28 (72.24%) followed by 30 (60.75%) and 118 (64.77%) at 2nd hour following exposure. Motility results were found to be in accordance with the vitality and morphology data where total abnormalities (especially reacted acrosome rate) were found to have increased.

Depletion of florfenicol and florfenicol amine residues in chicken eggs.

Abstract 1. The aim of this study was to develop a suitable method for the analysis of florfenicol (FF) and its metabolite florfenicol amine (FFA) in chicken eggs and to determine FF and FFA residue depletion in eggs of laying hens. 2. The analytes were extracted from yolk, albumen and whole egg by phosphate buffer and ethyl acetate. Following purification, samples were analysed by high-performance liquid chromatography. 3. Fifty laying hens were divided into 5 groups, and each hen received doses of 20 mg/kg FF: Group 1 (received a single oral dose by gavage); Group 2 (a single intramuscular dose); Group 3 (a single subcutaneous dose); Group 4 (multiple oral doses for 3 d) and Group 5 (multiple oral doses for 5 d). 4. Limits of detection and of quantitation values were 1.94 and 6.45 g/109 g (ppb) for FF, respectively, and 0.48 and 1.58 ppb for FFA, respectively. Relative standard deviation values of intra-day and inter-day variation below 11% also confirmed the usefulness of the method for analysing FF and FFA in eggs. 5. From the first day of both oral and parenteral administration, FF and FFA were detected at 0.1% and 0.08% of dosage, respectively, and 57% of the drugs were eliminated from the egg yolk. Elimination time of FF was 8 d in Groups 1, 2 and 3; 9 d in Group 4 and 10 d in Group 5.

Measurement of selected polychlorinated biphenyls (PCBs) in water via ultrasound assisted emulsification–microextraction (USAEME) using low-density organic solvents

Despite bans and restrictions for their adverse health effects including endocrine disruption, due to their stability in the environment, polychlorinated biphenyls (PCBs) are still of concern for their residues in several matrices. This study employed low-density ultrasound-assisted emulsification-microextraction (USAEME) to measure selected PCBs (28, 52, 101, 118, 138, 153, and 180) in water samples for gas chromatography-mass spectrometry analysis. Among tested solvents (isooctane, chloroform, hexane, and cyclohexane), 200 μL isooctane resulted in the highest yield for a 10 mL sample. The optimized method was validated and yielded recoveries of 87.29-92.83% with the limit of detection and limit of quantification (LOQ) values 3-12 ng/L and 10-40 ng/L, respectively. Twelve tap water samples collected in September 2014 were screened using this simple, rapid, and validated method. PCB concentrations in two samples were above the LOQ values; one sample contained 1,380 ng/L of PCB 118, 530 ng/L of PCB 138, and 152 ng/L of PCB 153, and the other contained 444 ng/L of PCB 138. Despite the city water supply being clean and the municipality employing all available measures to ensure clean water supply, the general public must be made aware of the regular maintenance of local water pipelines and storage tanks for the prevention of PCB contamination.

Determination of Polychlorinated Biphenyls in Marine Sediments by Ultrasound-Assisted Isolation and Dispersive Liquid–Liquid Microextraction and Gas Chromatography–Mass Spectrometry

ABSTRACT A new method is reported to determine polychlorinated biphenyls (PCBs) in marine sediments using ultrasound-assisted extraction and dispersive liquid–liquid microextraction with gas chromatography–mass spectrometry. To optimize the method, acetone, acetonitrile, and methanol were characterized for extraction from the sediments. Acetone provided the highest yield. A lower-density solvent system was utilized with isooctane and acetone, and the upper solvent was characterized by gas chromatography–mass spectrometry. The optimized procedure was validated. Sediments were fortified with PCBs 28, 52, 101, 118, 138, 153, and 180 at six concentrations from 0.25 to 8.0 ng g−1 and used to prepare matrix-matched calibration curves. Samples were analyzed using this optimized procedure. The linearity was satisfactory in all cases, with correlation coefficients from 0.9989 to 0.9995. The limits of detection and quantification were from 0.021 to 0.057 ng g−1 and 0.069 to 0.190 ng g−1, respectively. The recovery values at three fortified concentrations were 90.07–100.4% and the relative standard deviations were less than 7.6%. The reported extraction method uses a low-density, low-toxicity solvent; a sample syringe as the extraction device; and does not require additional purification after extraction from sediment. The protocol is sensitive, convenient, and ecofriendly and was used to determine PCBs in marines with satisfactory results.

Phthalate induced toxicity in prostate cancer cell lines and effects of alpha lipoic acid

OBJECTIVE The effects of dimethyl phthalate, diethyl phthalate, diisobutyl phthalate, di-n-butyl phthalate, benzylbutyl phthalate, di-2-ethylhexyl phthalate were investigated on human prostate cancer cell lines DU145 and PC3 in vitro. MATERIALS AND METHODS Standards of dimethyl phthalate, diethyl phthalate, di-isobutyl phthalate, dibutyl phthalate, benzyl butyl phthalate, and di-ethyl hexyl phthalate were used. Alpha lipoic acid was used as antioxidant compound. DU145 and PC3 human prostate carcinoma cells were used. MTT assay were used for cytotoxicity assay. RESULTS A low dose proliferative effect of phthalates in vitro was observed. With the hypothesis of the inhibition of aerobic glycolysis activity in cancer treatment, α-lipoic acid was applied to cells; where as a contrary to previous studies, no change in the cell proliferation was observed. In combination with ALA, at IC50 and lower doses, an increase of the cytotoxic effect was found for DIBP, DBP and BBP; while for DMP, DEP and DEHP, a decrease was observed for DU145 cells. In PC3 cells, a decrease was observed for DMP, DEP and DBPs; while no significant difference were observed for DEHP, DIBP and BBP. CONCLUSSION The present study demonstrates preliminary information regarding the low dose proliferative effects of phthalates in prostate cancer in vitro (Tab. 2, Fig. 2, Ref. 65).

Unio sp. primary cell culture potential in ecotoxicology research

Abstract Primary tissue cultures from Unio pictorum were developed for utilization in ecotoxicology studies. Cytotoxic effects of selected plasticizers (BPA, DiNP, DiDP, DMP) were tested on digestive gland, gonad, gill and mantle cells. DiNP on gill and BPA on digestive gland were the highest and lowest cytotoxic compounds (IC50 0.111, 170.718 ppt). Mantle cells were the most suitable, reliable and easy to maintain cells; for toxicity assays. Unio primary cell culture provide valuable tool for testing/screening effects of xenobiotics in vitro, have potential for further development in terms of potential cryopreservation and stability comply with the 3 R principle.