A stable and accurate frequency standard based on the 40.5 GHz ground-state hyperfine transition in 199Hg1 ions is described. The ions are confined in a cryogenic linear Paul (rf ) trap and laser cooled to form a linear crystal. With seven ions and a Ramsey interrogation time of 100 s, the fractional frequency stability is 3.3 s2d 3 10213t21y2 for measurement times t , 2 h. The ground-state hyp...

A cloud point extraction process using the nonionic surfactant Triton X-114 for extracting mercury from aqueous solutions was investigated. The method is based on the complexation reaction of Hg(II) with Thio-Michler's Ketone (TMK) and micelle-mediated extraction of the complex. The optimal extraction and reaction conditions (e.g., pH, reagent concentration, effect of time) were studied, and th...

Thiol-functionalized mesostructured silica with anhydrous compositions of (SiO(2))(1)(-)(x)()(LSiO(1.5))(x)(), where L is a mercaptopropyl group and x is the fraction of functionalized framework silicon centers, are effective trapping agents for the removal of mercuric(II) ions from water. In the present work, we investigate the mercury-binding mechanism for representative thiol-functionalized ...

The influence of halide and isothiocyanate ions of the reduction wave of aquopentamminecobalt(‡V) and aquopentamminechromium(‡V) ions at the dropping mercury electrode has been studied by the measurements of current-potential and current-time curves. The cobalt (‡V) complex ion gives a kinetic-controlled reduction wave at more positive potentials than that of the reduction of cobalt(‡V) to coba...

The properties of dry collodion membranes previously described allow the prediction that cells of these membranes will concentrate solutes under certain conditions. Three such cases have been studied experimentally. 1. A membrane containing thiosulphate and immersed in a solution of iodine concentrates iodide ion. 2. A membrane containing sodium chromate and immersed in mercury chloride concent...

BACKGROUND Associations between cardiovascular diseases and mercury have been frequently described, but underlying mechanisms are poorly understood. OBJECTIVES We investigate the procoagulant activation of erythrocytes, an important contributor to thrombosis, by low-level mercury to explore the roles of erythrocytes in mercury-related cardiovascular diseases. METHODS We used freshly isolate...

The EPA's recommended maximum allowable level of inorganic mercury in drinking water is 2 ppb (10 nM). To our knowledge, the most sensitive colorimetric mercury sensor reported to date has a limit of detection (LOD) of 800 pM. Here, we report an instrument-free and highly practical colorimetric methodology, which enables detection of as low as 2 ppt (10 pM) of mercury and/or silver ions with th...

The protease inhibitive assay for heavy metals is a novel and robust detection method suitable for preliminary screening method for detecting heavy metals in agriculture and environment samples. Stem bromelain has been previously showed to be sensitive towards mercury and copper. However, commercial preparation is in crude form and contains possible interfering entities. Using ion exchange and ...

Mercury is one of the most acutely toxic substances at trace level to human health and living thing. Developing a rapid, cheap and water soluble metal sensor for detecting mercury ions at ppb level remains a challenge. Herein, a metal sensor consisting of MPA coated Mn doped ZnSe/ZnS colloidal nanoparticles was utilized to ultrasensitively and selectively detect Hg(2+) ions with a low detection...