Aquaculture is an important nutrient for humans, and their living environment, sea water, must be of high quality. Toxic metals are one of the most important causes of marine pollution and marine organisms can accumulate such compounds in their bodies. It is extremely important to evaluate the health risks of fish, which is the most consumed sea creature by humans, in terms of toxic elements for public health. In this study, some heavy metal concentrations were determined using FAAS in the muscle and liver tissues of Trachurus trachurus species grown in the Marmara Sea, and the carcinogenic and non-carcinogenic risk possibilities related to these heavy metals were evaluated. According to the results of the research, it was seen that there was no relationship between fish weight and length and element content in muscle tissue. Compared with muscle tissue, liver tissue accumulated more metal content. It was determined that all elemental concentrations in muscle tissue were below the permissible limit. In addition, it was observed that these fish species were weak in terms of nutritional elements. The estimated daily intake values of all elements were found to be much lower than the reference doses. The target hazard quotient and hazardous index values for essential and toxic elements were below the limit value. It was decided that daily consumption of these fish does not pose a lifelong carcinogenic and noncarcinogenic health risk. The Pb concentration detected in the liver was observed to exceed the permissible limit. This situation suggests that the Marmara Sea should be examined in terms of Pb pollution.

In this study, a sensitive electrochemical method was developed for the determination of hydroxylamine (H−A) using a curcumin‐modified pencil graphite electrode prepared with the electropolymerization of curcumin (PolyCurc‐PGE). The PolyCurc‐PGE showed a remarkable electrocatalytic response for H−A oxidation compared with bare PGE. Amperometric and cyclic voltammetric measurements were performed based on the electrocatalytic oxidation of H−A at PolyCurc‐PGE. Some parameters, such as monomer concentration, pH, and cycle number during electropolymerization, were optimized to obtain the best electrochemical response of the modified electrode towards H−A. Results show that the PolyCurc‐PGE gives a linear response towards H−A oxidation in the range from 0.50 μM to 500 μM (R2=0.9984). In addition, the sensitivity and detection limit (LOD) of PolyCurc‐PGE were found to be 5432 μA mM−1 cm2 and 0.15 μM H−A, respectively. The developed amperometric method was successfully applied to determine H−A in pharmaceutical and water samples, and acceptable results were obtained with high accuracy and precision.

Curcumin and its derivatives named curcuminoids are naturally occurring polyphenolic compounds extensively marketed as a nutraceutical. The wide therapeutic potential of curcumin is highly explored by the authors. Therefore, pharma industries made many clinical inventions to bring it to the market as a drug. In this study, a simple, rapid, and sensitive High Performance Liquid chromatographic (HPLC) method for simultaneous determinations of curcumin, desmethoxycurcumin (DMC), and bis-desmethoxycurcumin (BDMC) was optimized and validated. Separation of curcumin, DMC, and BDMC was performed using the C18 column. Six factors, including the solvent type, ratio of mobile phase, flow rate of mobile phase, column temperature, injection volume, and wavelength, were investigated. The LOD and LOQ were observed to be 0.001 and 0.003 mg/L, R2 value < 0,99, respectively. RSD (%) is 0.974 for inter-day, and 1,312 for intra-day. Taking into consideration the retention time, peak area, resolution, and tailing factor, the optimum conditions were preferred: methanol as solvent, THF/Citric Acid (40/60) as mobile phase, flow rate of mobile phase at 0.5 mL/min, temperature of column at 30oC, injection volume at 20 µL and wavelength at 425 nm. The method is further used to determine ppm levels of curcumin derivatives, and recovery was found to be 90%. The proposed analytical method can be used for the quantification of curcumin in medicinal plants.