Syringe sampling technique for individual colorimetric analysis of reactive gases

Improvements in colorimetric analysis of chlorine and hydrogen fluoride by syringe-sampling technique

“…Chlorine. At concentrations above approximately 100 ppm Clg, the working o-tolidine solution (0.005 g/1., Meador and Bethea, 1970) was unusable. Under those conditions, the orange color formed by the reaction between CI2 and the o-tolidine became immediately pronounced and then faded completely within 5-10 min.…”

“…This adaptation of the lanthanum-alizarin-complexari method to the syringe-sampling procedure for airborne fluoride provides a greatly extended useful range with a fivefold increase in sensitivity over the ferric sulfosalicylate fluoride bleaching method used by Meador and Bethea (1970).…”

“…The syringe-sampling technique of Meador and Bethea (1970) has been extended to the colorimetric analysis of high concentrations of CI2 in stack samples. Additional work has also led to a change in the colorimetric procedure used for the analysis of trace quantities of HF in both ambient and stack samples.…”

Ensayos de materiales en atmósferas simuladas. I. Criterios para el diseño de sistemas de simulación

“…Fluoruro sódico con ácido sulfúrico (42,43) Reación química. Hidrógeno con trifluoruro de cobalto (37) Permeación (44) Inyección. Atomización de soluciones de ácido fluorhídrico (45) Evaporación a partir de soluciones de ácido fluorhídrico (46) aerosoles sólidos no suelen considerarse excesivamente peligrosos para la mayoría de los materiales y se les atribuyen efectos puramente antiestéticos; no obstante, cada vez son más frecuentes las opiniones acerca de la acción catalítica que puedan ejercer en las reacciones de los contaminantes entre sí y con la superficie de los materiales en las que se han depositado.…”

Determination of low concentrations of hydrogen chloride in moist air

“…Analysis of low concentrations of HC1 is a formidable experimental problem due to the chemical reactivity of hydrogen chloride in the presence of ambient moisture. Many techniques (6,7) and instruments (8) have been used for the analysis of hydrogen chloride including selective ion electrode (9), chemiluminescence (10), correlation spectrophotometry and coulometric methods (11).…”