A capillary electrophoresis chip for the analysis of print and film photographic developing agents in commercial processing solutions using indirect fluorescence detection

Abstract

The separation and detection of both print and film developing agents (CD-3 and CD-4) in photographic processing solutions using chip-based capillary electrophoresis is presented. For simultaneous detection of both analytes under identical experimental conditions a buffer pH of 11.9 is used to partially ionise the analytes. Detection is made possible by indirect fluorescence, where the ions of the analytes displace the anionic fluorescing buffer ion to create negative peaks. Under optimal conditions, both analytes can be analyzed within 30 s. The limits of detection for CD-3 and CD-4 are 0.17 mM and 0.39 mM, respectively. The applicability of the method for the analysis of seasoned photographic processing developer solutions is also examined.

Determination of the ascorbate content of photographic developer solutions using miniaturised isotachophoresis on a planar chip

“…The analysis of 5 different developer solutions, four fresh and one aged, was performed and the results are shown in Table 4. The ascorbate concentrations of the fresh samples (#1-4) were found to range between 0.0164 ± 0.0043 mol dm 23 and 0.0341 ± 0.0040 mol dm 23 , the errors shown being the SD based on 5 replicate runs. All of these concentrations are within the 0-0.0568 mol dm 23 range expected.…”

“…The following chemicals were used to produce these electrolytes: glycolic acid (99%, Fluka, Gillingham, Dorset, UK); tris(hydroxymethyl) aminoethane (Tris) (99.9%, Aldrich); hydroxyethyl cellulose (HEC) (molecular weight ca. 250 000) (Aldrich); glycylglycine (99+%, Acros, Loughborough, UK) and 0.05 mol dm 23 barium hydroxide volumetric standard (Riedel-de Haën, Gillingham, Dorset, UK). Model samples were prepared using L-ascorbic acid (99+%, Aldrich).…”

“…Model samples were prepared using L-ascorbic acid (99+%, Aldrich). Diethylenetriaminepentaacetic acid (DTPA) samples were prepared using the anhydrous form of this acid (98%, Aldrich) dissolved in 0.1 mol dm 23 sodium hydroxide (1.0 mol dm 23 volumetric standard, Aldrich). All samples and electrolytes were prepared using > 18 MW water (Elga Maxima Ultra Pure, Vivendi Water Systems, High Wycombe, UK).…”

“…A calibration curve was produced for ascorbate using five replicates of six samples with concentrations ranging from 0.01 mmol dm 23 to 0.5 mmol dm 23 . Good linearity was obtained with a correlation coefficient of 0.992 achieved.…”

“…The analysis of photographic developer solutions, albeit ones which do not contain ascorbic acid, has also been achieved using miniaturised CZE on a glass device. 22,23 This paper presents the first use of miniaturised ITP for analysing industrial process streams. The potential of this technique for such analyses is demonstrated through the analysis of ascorbate in photographic developer solutions on a planar PMMA separation device fitted with integrated conductivity detectors.…”