Vanadium(IV) and vanadium(V) can be determined by using differential pulse cathodic stripping voltammetry technique (DPCSV). Cupferron (ammonium N-nitrosophenylhydroxylamine) was used as ligand to form complex compounds with vanadium ions in Britton-Robinson buffer (BRB) solution. At concentration lower than 1.0×10(-6) M, both V(IV) and V(V) cupferron complexes showed a single cathodic peak at -0.576 V in BRB of pH 4; thus V(IV) and V(V) ions cannot be differentiated at low concentration. However, the ionic species of vanadium can be differentiated at high concentration in the presence of cupferron. Parameters including pH of BRB solution, initial potential and accumulation potential were optimized. Under the optimized parameters, the limit of detection (LOD) was 0.09 nM, and the peak current was linear in the concentration range 0.01-0.9 µM total vanadium ions. The determination of V(IV) and V(V) ions was carried out at higher concentration in the sample using calibration plot method. At higher concentration range of 10-60 µM V(IV) and V(V) ions were determined with LOD of 1.2 and 1.1 µM, respectively. The developed method was successfully applied to 10,00,000 fold diluted Benfield sample and 0.6227 M total vanadium ions were determined. The determination of V(IV) and V(V) ions were also successfully carried out in artificial sample as well as Benfield sample (dilution factor, 10,000). The concentration of V(IV) and V(V) ions was 22.52 µM and 38.91 µM, respectively, giving total vanadium concentration of 0.6143 M in Benfield sample.
Introduction: One of the risk factors for cancer is the habit of smoking. Some carcinogenic substances in ciga-rettes are nicotine and nitrosamine. In cigarette smoke there are free radical molecules or Reactive Oxygen Species (ROS) that can cause DNA mutations that can disrupt the balance of cell metabolism. One of them is the apoptosis, apoptosis is a programmed cell death mechanism. In cancer conditions there are apoptotic disorders and excessive proliferation of cells. The process of apoptosis is influenced by the death receptor, Tumor Necrosis Factor apoptosis inducing ligand R1 (TRAIL R1). This study aims to determine the effect of smoke exposure to expression of TRAIL R1 on the mucosal epithelium of the tongue of the Wistar rat (Rattus Novergicus). Methods: The subjects of this study were 24 male Rattus Novergicus with the age range of 12-14 weeks and weighing ± 170 grams. Divided into 4 groups with 2 control groups 4 weeks (K4), 8 weeks (K8) and 2 treatment groups each given 2 cigarettes / day ex-posure to cigarette smoke for each rat for 4 weeks (P4) and 8 weeks (P8). Results: The results showed that exposure to cigarette smoke can cause interference with TRAIL R1 expression. There was a significant difference in TRAIL R1 expression between the control and treatment groups and there was a significant difference in TRAIL R1 expression between the duration of cigarette smoke exposure (P4 and P8). Conclusion: Exposure to cigarette smoke can interfere with the process of apoptosis.