Atomization efficiencies in halocarbon-loaded acetylene-air flames—I. Monochlorides of readily volatilized elements

Matrix Effect of Alkali and Alkaline Earth Metal Halides on Fluorescence Quantum Yield of Indium in Laser‐Induced Fluorescence Flame Spectrometry

“…Sec ond, the re leased non-metal at oms may lead to a chem i cal re ac tion with the analyte to form an in dium monohalide compound, which causes sup pres sion of the LIF sig nal. 3,4,30,31 Third, the ma trix it self or the re leased spe cies, in clud ing the elec trons, may in ter fere with the ex cited state of In, thereby en hanc ing the radiationless collisional de ac ti va tion. 9,10,32 In this work, the nor mal ized flu o res cence sig nal is treated to pre vent de vi a tions due to vari a tions of the at om iza tion ef ficiency un der the con di tions with and with out the ma trix added.…”

“…34 Given the elec tron num ber den sity, n e , the ra di a tive life time, o, of the ex cited state and the quench ing rate co ef ficient of elec tron-atom col li sions, the quan tum yield, Y, may be cal cu lated as fol lows: 9,32 (3) Among those pa ram e ters re quired, the elec tron num ber density may be de ter mined from the equi lib rium con stant for flame ion iza tion. Ac cord ing to the Saha equa tion, this ion ization equi lib rium con stant for the analyte or the ma trix in the flame can be ex pressed in terms of the re lated par ti tion function by 33 (4) where nA, nA+, and ne de note the num ber den si ties of at oms, ions and elec trons, re spec tively, h is the Planck's con stant, Qi and Q A are the elec tronic par ti tion func tion of the ion and the atom, re spec tively, and Vi is the ion iza tion po ten tial. The ion tem per a ture is con sid ered to be equal to the elec tron tem per ature un der the con di tions of ther mal equi lib rium.…”

“…A better un der stand ing of the in ter fer ence mech a nisms in volved seems to be cru cial to re duc ing ef fectively the ma trix in ter fer ence and mea sur ing trace analytes pre cisely, in ad di tion to op ti miz ing the op er at ing con di tions. Es sen tially the re sul tant in ter fer ence may cause such ef fects as shift ing the ion iza tion equlibrium of the analyte, 1,2 in ducing chem i cal re ac tions, 3,4 vary ing the prop er ties of analyte vol a til iza tion 5,6 and at om iza tion, 7,8 quench ing the analyte pop u la tion in the ex cited state, 9,10 chang ing the trans port prop er ties of so lu tions into a flame or an ICP sys tem, 11,12 reform ing the spa tial dis tri bu tion of the analyte pop u la tion, 13,14 caus ing broad en ing of the line shape 15,16 and af fect ing the diffu sion of the con cen tra tion gra di ent 17,18 and sys tem tem per ature. 19,20 The phys i cal and chem i cal phe nom ena in volved are very com pli cated and thus the in ter pre ta tion is very di ver sified.…”

“…[1][2][3][4] The for mer pro cess re sults in a sub stan tial increase in the num ber of the elec trons, which may sup press the ion iza tion of the analyte be ing de tected. On the other hand, the chem i cal re ac tion with the ma trix added may con sume the analyte and thus de press the ab sorp tion sig nal.…”

Atomic Absorption, Atomic Emission, and Flame Emission Spectrometry

“…Kantor and Ernyei (289,290) examined the effects of halocarbons, introduced as vapors, on the atomization efficiencies of several elements. In some cases, signal depression was attributed to the formation of monochloride (289) or dichloride (290) species, and in others incomplete solute vaporization (290) was blamed. LASER TECHNIQUES Omenetto (291) reviewed the use of tunable lasers in atomic spectrometry, with particular reference to laser-excited atomic fluorescence and laser-enhanced ionization spectrometry.…”