Platinum plasmas

Chen et al. utUized a direct chemical reaction with a given solution (wet treatment) to modify the surface of the silicone rubber. The presence of a layer of PEO on a biomaterial surface is accompanied by reductions in protein adsorption, and cell and bacterial adhesion. In order to obtain a PEO layer on top of the silicone rabber surface, the surface was firstly modihed by incorporating an Si-H bond using (MeHSiO) , and followed by PEO grafting to the surface using a platinum-catalyzed hydrosilylation reaction. These PEO-modified surfaces were demonstrated by fibrinogen adsorption both from buffer and plasma, as well as albumin adsorption from buffer. Reductions in protein adsorption of as much as 90% were noted on these surfaces. 

Solid metal electrodes are usually polished mechanically and are sometimes etched with nitric acid or aqua regia. Purification of platinum group metal electrodes is effectively achieved also by means of high-frequency plasma treatment. However, electrochemical preparation of the electrode immediately prior to the measurement is generally most effective. The simplest procedure is to polarize the electrode with a series of cyclic voltammetric pulses in the potential range from the formation of the oxide layer (or from the evolution of molecular oxygen) to the potential of hydrogen evolution (Fig. 5.18F). 

Turyan and Mandler [483] determined ppt levels of mercury in seawater by first converting mercury salts to elemental mercury using stannous chloride, the mercury was then trapped on gold deposited on platinum gauze and released by heating prior to determination by inductively coupled plasma mass spectrometry. 

Debrak and Denoyer [484] determined mercury at the ppt level in seawater by the addition of tin chloride to produce hydrogen vapour, and trapping on gold-platinum gauze, prior to heating and detection of the mercury released by inductively coupled plasma mass spectrometry. 

Figure 2.9 Inductively coupled plasma detection of diaminodichloroplatinum(n). Conditions column, Shodex OH, 25 cm x 4.1 mm i.d. eluent, 0.01 m phosphoric acid flow rate, 1 ml min-1 detector, emission at platinum line 265.9 nm. Samples cis and trans diaminodichloroplatinums. The second peaks are considered to be their oligomers.

G. K. Poon, P. Mistry, F. I. Raynaud, K. R. Harrap, B. A. Murrer, C. F. J. Barnard, Determination of Metabolites of a Novel Platinum Anticancer Drug JM216 in Human Plasma Ultrafiltrates ,./. Pharm. Biomed. Anal. 1995, 13, 1493 - 1498. 

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