An evaluation of some fluorescent dyes for water tracing

Abstract

Eight fluorescent dyes (amino G acid, photine CU, fluorescein, lissamine FF, pyranine, rhodamine B, rhodamine WT, and sulpho rhodamine B) were compared in laboratory and field experiments to assess their utility in quantitative tracing work. The properties considered included sensitivity and minimum detectability, the effect of water chemistry on dye fluorescence, photochemical and biological decay rates, adsorption losses on equipment and sediments, toxicity to man and aquatic organisms, and cost. The orange fluorescent dyes are more useful than the blue and green because of the lower background fluorescence at the orange wave band, which permits higher sensitivities to be obtained. Pyranine fluorescence is strongly affected by pH over the range encountered in natural waters, which precludes its simple use in quantitative work. Amino G acid, photine CU, pyranine, and fluorescein all have high photochemical decay rates. Pyranine, lissamine FF, and amino G acid are the dyes most resistant to adsorption, but rhodamine WT, fluorescein, and sulpho rhodamine B also have moderately high resistance. Rhodamine B is readily adorbed by most materials. Rhodamine WT (orange), lissamine FF (green), and amino G acid (blue) are the three tracer dyes recommended; they may be used simultaneously to trace three injection sites with the filter combinations suggested. 1972]. Of the commonly used fluorescent dyes, fluorescein (Colour Index (CI)45350 [Society of Dyers and Colourists, 1971]) has been used since the end of the nineteenth cent•ury [Dole, 1906]. It is visibly detectable in low concentrations but has very poor stability under sunlight. Thus in the early 1960's, when workers in the United States and Japan were assessing fluorescent dyes for quantitative tracing work in surface waters, they adopted the equally fluorescent dye rhodamine B (CI 45170 [Pritchard and Carpenter, 1960]). However, it became apparent that rhodamine B was readily adsorbed onto sediments, and subsequently, sulpho rhodamine B (CI 45100) was introduced. Although this dye was resistant to adsorption, it was comparatively expensive and was later replaced by the cheaper Copyright ¸ 1976 by the American Geophysical Union. Paper number 6W0149. dye rhodamine WT, which was developed specifically for tracing work (U.S. patent 3, 367, 946). Reynolds [1966] used the green dye pyranine (CI 59040) for tracing percolation water because it was very resistant to adsorption. Recently, a group of' blue fluorescent dyes, known as optical brighteners because of their use in whitening paper, textiles, and other off-white products, have been applied to water tracing [Glover, 1972].There has been a little previous work on the suitability of rhodamine WT for water tracing, but considerably more data are available for fluorescein, sulpho rhodamine B, and rhodamine B. However, much of this information cannot be directly compared between one study and another because of differences in experimental techniques. Furthermore, little work has been presented on the use of pyranine, the...

Natural dispersion in a small lake

“…This occurred between 22 and 46 min after the dye release (we were not concerned about photochemical decay of the dyes, because it only becomes significant after several hours for sodium fluorescein, and after many days for Rhodamine WT, see Smart and Laidlaw 1977). At the other extreme we followed Okubo's (197 1) recommendation to ignore data taken before the dye patch had grown large enough to have "forgotten" its initial conditions (i.e.…”

An assessment of steady-state propane-gas tracer method for reaeration coefficients — Cowaselon Creek, New York

“…17 is a very reasonable approximation because the dye loss involved is normally small (Smart and Laidlaw, 1977).…”

“…Remembering that the transverse variation of high as 5 to 7 percent at some sections in the summer tests, the reliability of the mass recovery calculation for the October test w dye cloud area, a, was as th only one transverse sampling does not appear to be very high. In a comparable streiam test of rhodamine WT, Smart and Laidlaw (1977) reported no loss for the resjdence time of 3.5 hours and 2 percent loss for 7.4 hours, despite the fact that1 the stream contained a large growth of weeds. The best current judgement Appears to be that the fractional dye loss for the residence time of a few hours is on the order of 5 percent or less.…”

Tracer tests in fractured rocks with a new fluorescent dye—pyrene-1,3,6,8-tetra sulphonic acid (PTS) / Tests de traçage en roches fracturées avec un nouveau produit fluorescent—l'acide pyrène 1.3.6.8 tétra sulfonique (PTS)

“…The field tests had two main goals: (a) the examination of the PTS-transport behaviour in the fissured aquifers in comparison to pyranine and uranine, which are regarded by Smart & Laidlaw (1977) as non-reacting dyes under favourable conditions in porous aquifers; and (b) the estimation of rock parameters at the LRL ore dike and the fault-zone AU 126 of the GTS. Rock parameters found at the LRL were compared to those previously obtained by Himmelsbach et al (1998) who used deuterium, pyranine and uranine.…”

“…In comparison to the commonly used uranine, the PTS tracer has a very low degradation in the presence of light and in column experiments in tertiary sand and quaternary gravel it shows significantly lower sorption at lower pH values (<pH 7) than uranine (Einsiedl et al, 1999). Generally, fluorescent tracers show different transport behaviour depending on the pH value (Smart & Laidlaw, 1977;Einsiedl, 1999). However, at pH values above 9, all used fluorescent dyes should have an anionic character and in consequence low or non-reacting transport behaviour.…”