Detection Faraday

Stevenson, L, Apple, L, Cormack, P,A, Graham, D, Smith, W,E, Corish, P, Lipscomb, S,J, Holland, E,R, and Prince, P,D, (2006) SERRS labelled beads for multiplex detection, Faraday Discussions, 132, 303-8 discussion 309-19,... 

Calcium hexacyanoferrate (II) (IIH2O) [ 13821 -08-4] M 490.3. Recrystd three times from conductivity H2O and air dried to constant weight over partially dehydrated salt. [Trans Faraday Soc 45 855 1949.] Alternatively the Ca salt can be purified by pptn with absolute EtOH in the cold (to avoid oxidation) from an air-free saturated aqueous soln. The pure lemon yellow crystals are centrifuged, dried in a vacuum desiccator first over dry charcoal for 24h, then over partly dehydrated salt and stored in a dark glass stoppered bottle. No deterioration occurred after 18 months. No trace of Na, K or NH4 ions could be detected in the salt from the residue after decomposition of the salt with cone H2SO4. Analyses indicate 1 Imols of H2O per mol of salt. The solubility in H2O is 36.45g (24.9 ) and 64.7g (44.7 ) per lOOg of solution. [J Chem Soc 50 1926.]... 

Lead nitrate [10099-74-8] M 331.2, m 470°. Ppted twice from hot (60°) cone aqueous soln by adding HNO3. The ppte was sucked dry in a sintered-glass funnel, then transferred to a crystallising dish which was covered by a clock glass and left in an electric oven at 110° for several hours [Beck, Singh and Wynne-Jones Trans Faraday Soc 55 331 1959], After 2 recrystns of ACS grade no metals above 0.001 ppm were detected. 

Consideration of Faraday s law shows the advantage of electrochemistry for analytical purposes. With currents as small as 10 A easily measurable, conversion rates of as little as eq/s are readily detectable. This means detection limits in the range... 

The specimen chamber (or target chamber) may contain a number of samples and standard specimens mounted on the same sample holder. Also here are the X-ray detection system and a Faraday cup which monitors the proton current incident... 

The measurement is always relative, that is, in 14C measurements the amount of 14C is always related to that of 13C or 12C. The more abundant isotope is detected by a Faraday detector while the less abundant isotope is detected by a specialized device... 

To obtain a mass spectrum, ions need to be converted into a usable signal by a detector. The simplest form of ion detection is a photographic plate or a Faraday cup for the direct measurement of the charge. In a Faraday cup the induced current is generated by an ion which hits the surface of a dynode and emits... 

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