Silicon arsenic hydrides

Of all the reactions studied, only the synthesis of nitrogen oxides and acetylene in arcs or plasma torches and that of ozone in glow and corona discharges are of major importance. In addition, a few small-scale preparations of inorganic compounds have been developed, e.g. synthesis of hydrazine and of hydrides and halides of silicon, germanium, tin, lead, phosphorus or arsenic 3> ... 

Silicon may be present in various forms in some preparations, e.g. as tri-silicate in antacids, polydimethyl-siloxane or silicone oil (see also section VII, ref. 77). The sample may be evaporated to dryness and the residue fused with sodium bicarbonate or another fusion agent, or taken up in hydrofluoric acid provided strong heating and loss of silicon is avoided. A nitrous oxide/acetylene flame must be used. Chromium may be found in disinfectants and antiseptics. Unless dilution of the sample is possible the use of the injection-cup technique (see section II.A) may be preferable as otherwise large amounts of corrosive salts such as sodium hypochlorite will be aspirated. If iron is also present it may be necessary to use a nitrous oxide/ acetylene flame. Arsenic in arsenamide and lead arsenate preparations can be determined by boiling the sample in 5% nitric acid and aspiration of the sample [111]. Better sensitivity would be obtained using hydride generation (see section II.A). 

Ignition or explosive reaction with metals (e.g., aluminum, antimony powder, bismuth powder, brass, calcium powder, copper, germanium, iron, manganese, potassium, tin, vanadium powder). Reaction with some metals requires moist CI2 or heat. Ignites with diethyl zinc (on contact), polyisobutylene (at 130°), metal acetylides, metal carbides, metal hydrides (e.g., potassium hydride, sodium hydride, copper hydride), metal phosphides (e.g., copper(II) phosphide), methane + oxygen, hydrazine, hydroxylamine, calcium nitride, nonmetals (e.g., boron, active carbon, silicon, phosphoms), nonmetal hydrides (e.g., arsine, phosphine, silane), steel (above 200° or as low as 50° when impurities are present), sulfides (e.g., arsenic disulfide, boron trisulfide, mercuric sulfide), trialkyl boranes. 

---