ABSTRACT
BACKGROUND: Voltammetric analysis of the neurotransmitter epinephrine (EP) was performed using bismuth immobilized on a carbon nanotube paste electrode (BCE), whose properties were compared with those of a carbon nanotube paste electrode (CE). BCE was found to be more efficient in detecting EP. METHODS: The analytical parameters used were 0.3 V square-wave (SW) stripping voltammetric amplitude, 400 Hz frequency, -0.8 V initial potential, and 0.015 V increment potential. The optimized conditions were applied to an assay of a carp's front fin. RESULTS: A BCE was inserted into a carp's front fin muscle, and a stimulus was given every 50 s. This circuit is easy to use and does not require much analytical preparation time. CONCLUSIONS: The working electrode is miniscule, and its detection limit is very low. The in vivo muscle's chronoamperometric nerve currents were analyzed. These results have potential for applications in medical diagnostics, pharmaceuticals, interface controllers, and other fields.
ABSTRACT
The presence of trace metal cadmium assay was investigated with a copper immobilized on a graphite carbon electrode (GPC), the modified property of which was determined with handheld voltammetric systems. Following the determination of the analytical stripping conditions of 0.45 V amplitude, 30 Hz frequency, -1.4 V initial potential, and 4.0 mV increment potential, only a 60-s experimental accumulation time was used. Using these conditions, the analytical detection limit approached the nano range. At this condition, the analytical application was performed on distilled alcoholic drinks for food manufacturing systems. This developed technique is faster and less costly than the common voltammetric and spectrophotometric methods.
Subject(s)
Alcoholic Beverages/analysis , Cadmium/analysis , Electrochemical Techniques/methods , Trace Elements/analysisABSTRACT
A method of detecting lead was developed using square wave anodic stripping voltammetry (SWASV) with DNA-carbon nanotube paste electrode (CNTPE). The results indicated a sensitive oxidation peak current of lead on the DNA-CNTPE. The curves were obtained within a concentration range of 50 ngL(-1)-20 mgL(-1) with preconcentration time of 100, 200, and 400 sec at the concentration of mgL(-1), µgL(-1), and ngL(-1), respectively. The observed relative standard deviation was 0.101% (n = 12) in the lead concentration of 30.0 µgL(-1) under optimum conditions. The low detection limit (S/N) was pegged at 8 ngL(-1) (2.6 × 10(-8) M). Results showed that the developed method can be used in real-time assay in vivo without requiring any pretreatment and pharmaceutical samples, and food samples, as well as other materials requiring water source contamination analyses.
ABSTRACT
A mercury film (MF) is prepared by an electrochemical deposition on a glassy carbon electrode (GCE), and employed for an analysis of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) using square-wave stripping voltammetry (SWSV). RDX was deposited at -0.15 V (vs. Ag/AgCl) for 120 s, then reduced at -0.7 V on the MF coated GCE(MFGCE). Optimal experimental conditions were searched and reported for the analysis. Two linear concentration ranges were observed: one in a lower RDX concentration range of 0.2-10 mg l(-1) and the other in a higher RDX concentration range of 10.0-100.0 mg l(-1) with a 120 s of pre-concentration time. At RDX concentrations of 2 and 8 mg l(-1), the relative standard deviations in measured concentrations (n=16) were 9.79 and 0.49%, respectively. The detection limit found to be 0.12 mg l(-1) with the 120 s accumulation time. The method was applied to determine RDX in several soil samples that yielded a relative error of 1% in the concentrations.
