Analytical applications of furnace atomic non-thermal excitation spectrometry (FANES) and molecular non-thermal excitation spectrometry (MONES). Part 4. Determination of trace amounts of phosphorus by FANES

Abstract

A method of determining phosphorus by furnace atomic non-thermal excitation spectrometry (FANES) has been developed. The phosphorus is introduced into the FANES source as a solution of sodium dihydrogen phosphate. The measurements are carried out at 213.5/213.6 and 253.3E53.5 nm, the transition at 213.5/213.6 nm being the more sensitive one. The thermal and chemical conditions were optimised, the best chemical modifier being La3+ ions as they stabilise phosphate ions as LaP04. Using the optimum amount of lanthanum (2 pg) the pre-treatment temperatures could be increased considerably (300 to 800°C at normal pressure and 350 to 400°C at low pressure). The best detection limit obtained is 90 pg of phosphorus, which is an improvement by a factor of 60 in comparison with the best values obtained with commercially available electrothermal atomisation atomic absorption spectrometric (ETAAS) instruments. Examples for real analyses with associated matrix interferences are given.

Figures of merit for furnace atomization plasma emission spectrometry

“…It is noteworthy that nonmetals such as P can be detected with the FANES and FAPES systems. In the present case, the LOD reported for P is superior to the best values obtained from either GFAAS, i.e., 3000 pg (15), or FANES, i.e., 150 pg (16).…”

“…This scan was obtained at a furnace temperature of 700 K and a forward plasma power of 50 W. A highly structured background is evident in the region 200-500 nm, containing intense molecular bands arising from CO, NO, OH, and N2 as well as intense lines from He I. Bands arising from the fourth positive system of CO have not been labeled on Figure 4a in an effort to keep the congestion of information to a minimum. However, the following band heads are evident: (3,10), (4,11), (5,12), (3,11), (6,14), (7,15), (4,13), (8,16), and (7,16) as the presence of other additional (unidentified) species. Beyond 500 nm, the plasma background is relatively structureless and, with the exception of some discharge gas lines, the few features evident in Figure 4e have not been identified.…”

Atomic absorption, atomic emission, and flame emission spectrometry

“…This was illustrated (291) by the determination of chloride and bromide using both atomic and ionic emission lines. For the determination of P, FANES gave a much lower detection limit than ETAAS (292). Molecular nonthermal excitation spectrometry (MONES) was used for the determination of P (293) and S (294).…”

A spectral phosphorus determination using its electrothermal and atomization with various chemical modifiers (Review)

“…Использование ЭТИ и ЭТА фосфора возможно также в вариантах спек-трометрии атомного нетермического возбуждения в печи (Furnace Atomic Non-thermal Excitation Spectrometric -FANES) [41] и спектрометрии молекуляр-ного нетермического возбуждения в печи (Molecular Non-thermal Excitation Spectrometry -MONES) [42]. Во всех этих методах анализа ЭТИ и ЭТА ве-дут в инертной атмосфере в электрически нагре-ваемых до 2700-2800 о С трубчатых печах или пе-чах с платформами, чаще всего графитовых.…”