Atomic emission characteristics of a premixed acetylene-nitrous oxide, total consumption flame.
It is well known that most of the burners presently used to produce high temperature, premixed flames have the tendency to be discouragingly wasteful of the sample solution, often bringing only a small fraction of the amount used into the flame. This paper reports on the construction and performance of a highly efficient total consumption burner that produces a nonturbulent acetylene-nitrous oxide flame from premixed gases. The eighteen flame emission detection limits tabulated for a select group of elements compare favorably with the best values heretofore reported in the literature, and the apparent freedom of alkaline earth emission from phosphate interference indicates the total consumption flame here described to be less subject to chemical interference than is the conventional diffusion flame. The relatively low cost burner that has been developed is convenient to operate and can be quickly assembled from commercially available components.
Characteristics of premixed, laminar CO/N2O flames
Several properties are studied of fuel-rich (CO:N2O = 1.5:1) and stoichiometrie (CO:N2O = 1:1) carbon monoxide/nitrous oxide flames with varying water content up to 10%. Flame temperatures, ranging from 2680 to 2860°K. are measured with the line-reversal method, and compared with calculated adiabatie values. Excess concentrations of H and OH radicals are determined by the LiOH/Li method; the ratios [H]/[H2O] appear to exceed their (calculated) equilibrium values by a factor 1.5 to 3.0. even after 10 msec rise time of the flame gases. Burning velocities of the various mixtures, estimated from the height of the combustion cones, range from 30 to 75 cm/see and are markedly dependent on the water content of the mixture. The absolute spectral intensity of the (quasi) continuous emission of the burnt pases was measured and was found to have the same dependence on CO and O concentrations as in CO/air flames. Electron concentrations of 109 to 1010 cm−3, measured with a HF resonance method, are tentatrvely attributed to (thermal) ionization of NO.
A STUDY OF THE FLAME EMISSION CHARACTERISTICS OF LANTHANUM IN AN AQUEOUS- ALCOHOLIC MEDIUM
Abstract The determination of lanthanum by measuring its flame emission at several wave lengths has been evaluated by means of two recording spectrophotometers equipped with special photomultiplier detecting devices. In addition, a comparison of the effect of an aqueous and alcoholic medium was carried out. In general, the interference from foreign ions is least at the higher wave length of 743 mμ. In most cases, especially with transition elements, the interference is lessened when 1 : 1 water-methanol solution is used. The exceptions to this rule are titanium,thorium and zirconium which cause less interference in an aqueous solution. The method used in conjunction with a standard addition technique, has been applied to the determination of lanthanum in solutions of thorium oxide, uranium, glass, and didymium oxide mixtures.