Abstract: Adrenaline(I), noradrenaline(II) and dopamine(III) were selectively adsorbed from plasma on a column (1 cm x 4.6 mm) of benzeneboronic acid gel (Affi-Gel 601) or from urine on a column (2 cm x 3.8 mm) of dihydroxyboryl-silica or Aba-silica, and were eluted with aqueous H3PO4 containing 2 mM Na decyl sulfate(IV). The eluted catecholamines were enriched as ion pairs on a column (2 cm x 4.6 mm) of Supelcosil LC-18-DB (5 µm), before elution with methanol - buffer solution (1:4) and separation on a column (7.5 cm x 4.6 mm) of Supelcosil LC-18-DB (3 µm), with phosphate buffer (pH 6.65) - citrate buffer (pH 6.65) - methanol (3:3:2) (containing 2 mM (IV) and 0.3 mM EDTA) as the mobile phase (0.9 mL min-1). III was detected by coulometry at +0.3 V, and I and II by fluorimetry, as the trihydroxyindoles after post-column derivatization, at 510 nm (excitation at 400 nm). The limits of detection were 0.05, 0.04 and 1.6 pmol for I, II, and III, respectively, with coefficient of variation between 2 and 4%.

Abstract: Aqueous samples were analyzed directly whereas viscous samples, e.g., shampoo, were diluted 25-fold with H2O; samples containing H2O-insoluble components were extracted by the method of Engelhardt and Klinkner (Ibid., 1985, 20, 559). Analysis was carried out by HPLC on a column (15 cm x 4.6 mm) of PLRP-S (5 µm). The mobile phase (1 mL min-1) was 0.05 M H2SO4 and detection was by fluorescence at 460 nm (excitation at 390 nm) after derivatization of analytes with 5,5-dimethylcyclohexane-1,3-dione(I). The detection limits of formaldehyde and acetaldehyde were 1 and 0.5 ng, respectively. A method for preparation of stable I with low background fluorescence is described.

Abstract: Sulfated polysaccharides, including heparin and carrageenans, were determined by the formation of fluorescent complexes with Ce3+. The reaction system incorporated a strong cation-exchange tubular membrane reactor (SciTech, Umea, Sweden). In one mode, Ce2(SO4)3 was added to the carrier solution flowing in the internal channel, and 50 mM H2SO4 flowed in the external channel; the anionic polymers were equilibrated initially with aqueous Ce(SO4)2 of the same concentration. as the carrier, and unreacted Ce3+ was removed by the H2SO4. In the other mode, the carrier was 50 mM ammonium acetate pumped through the reactor, and Ce3+ was introduced from 2 to 4 mM Ce2(SO4)3 in 50 mM H2SO4 flowing in the external channel. The fluorescence of the products was measured at 350 nm (excitation at 250 nm). Either mode could be used in flow injection analysis; the second mode was used in conjunction with size-exclusion LC on a column (30 cm x 1 cm) of Superdex (13 µm) in which the carrier also constituted the mobile phase. Samples could be desalted on a Biosil guard column (8 cm x 7.8 mm; 5 µm particles) for flow injection analysis. Response to anionic polymers was high and that to low-mol.-wt. acids was small or absent; there was a small negative response to oxalic acid. The detection limit in flow injection analysis was 1 pmol with 50 mM ammonium acetate and 0.1 pmol with water as carrier for heparin, and response was rectilinear over three decades of concentration.