No abstract

No abstract

A simple and sensitive preconcentration strategy using sequential electrokinetic and hydrodynamic injection modes in micellar electrokinetic chromatography with diode array detection was developed and applied for the separation and determination of anticancer agent, 5‐fluorouracil and its metabolite, 5‐fluoro‐2′‐deoxyuridine, in human plasma. Sequential injection modes with increased analyte loading capacity using the anionic pseudo‐stationary phase facilitated collection of the dispersed neutral and charged analytes into narrow zones and improved sensitivity. Several important parameters affecting sample enrichment performance were evaluated and optimized in this study. Under the optimized experimental conditions, 614‐ and 643‐fold and 782‐ and 803‐fold sensitivity improvement were obtained for 5‐fluorouracil and its metabolite when compared with normal hydrodynamic and electrokinetic injection, respectively. The method has good linearity (1–1,000 ng/ml) with acceptable coefficient of determination (r2 > 0.993), low limits of detection (0.11–0.14 ng/ml) and satisfactory analyte relative recovery (97.4–99.7%) with relative standard deviations of 4.6–9.3% (n = 6). Validation results as well as the application to analysis of human plasma samples from cancer patients demonstrate the applicability of the proposed method to clinical studies.

No abstract

The presence of heavy metals in the environment can have a negative impact on living beings and the environment. This study aimed to evaluate the potential human health risks associated with exposure to heavy metals in drinking water from Kulim Hi-Tech Park (KHTP), Malaysia. Thirty water samples were collected from different locations within and around KHTP, and the concentration of five heavy metals (iron (Fe), manganese (Mn), zinc (Zn), cadmium (Cd), and nickel (Ni)) was determined using atomic absorption spectroscopy. The mean concentration of these heavy metals ranged from 0.0177 ±0.0017 mg/L to 0.8652 ±0.0606 mg/L, with the mean concentration order being Ni> Fe> Zn > Mn> Cd. Iron, cadmium, and nickel exceeded the permissible limits. The Hazard Quotient (HQ) values for Fe, Zn, and Mn were ranked in the order of Fe > Zn > Mn. However, the individual and total HQ and Hazard Index (HI) values were below 1, suggesting no expected negative impact on human health. Nevertheless, the Excess Lifetime Cancer Risk (ELCR) values for Cd and Ni in the entire population of adults and children ranged from 2.35E-02 to 5.79E-03, indicating that the levels of Cd and Ni in water resources in KHTP and its surrounding area may be above safe levels and require proper remediation to minimize the risk to human health. The study establishes a baseline for heavy metal contamination in KHTP and nearby water resources, emphasizing the need for further research to safeguard Kulim's environment and residents.