TY - JOUR
T1 - Determination of salicylate, gentisic acid and salicyluric acid in human urine by capillary electrophoresis with laser-induced fluorescence detection
AU - Zaugg, Sandra
AU - Zhang, Xin
AU - Sweedler, Jonathan
AU - Thormann, Wolfgang
N1 - Funding Information:
The excellent technical assistance for SA monitoring with the photometric assay and FPIA provided by Mrs. Yolanda Aebi is gratefully acknowledged. This work was partly sponsored by the Swiss National Science Foundation. The wavelength-resolved CZE-LIF work was supported by the USA National Science Foundation (CHE 9877071) and the Camille Dreyfus teacher scholar award to JVS.
PY - 2001/3/5
Y1 - 2001/3/5
N2 - Acetylsalicylic acid (Aspirin) is rapidly metabolized to salicylic acid (salicylate) and other compounds, including gentisic acid and salicyluric acid. Monitoring of salicylate and its metabolites is of toxicological, pharmacological and biomedical interest. Three capillary electrophoresis (CE) methods featuring alkaline aqueous buffers, laser-induced fluorescence (LIF) detection and no solute extraction or derivatization have been explored. A competitive binding, electrokinetic capillary-based immunoassay is developed that recognizes the presence of salicylate and gentisic acid in urine. Differentiation of the two compounds, however, is problematic. With appropriate ultraviolet excitation, many salicylate-related compounds are fluorescent so that CE with direct urine injection and LIF detection permits the determination of salicylate, gentisic acid and salicyluric acid. Using a HeCd laser with 325 nm produces interference-free monitoring of all three compounds. Using 257 nm excitation from a frequency doubled Ar ion laser, native fluorescence of an endogenous urinary compound that co-migrates with gentisic acid is observed. With wavelength-resolved fluorescence detection, however, the two substances are distinguished. Furthermore, this technique, with comparison to literature data, permits the putative assignment of several peaks to other salicylate metabolites, namely glucuronide conjugates of salicylate and salicyluric acid. All three CE-LIF techniques have been applied to toxicological patient urines and urines collected after ingestion of 500 mg acetylsalicylic acid. CE results compare favorably with those obtained by a commercial fluorescence polarization immunoassay and by a conventional photometric assay.
AB - Acetylsalicylic acid (Aspirin) is rapidly metabolized to salicylic acid (salicylate) and other compounds, including gentisic acid and salicyluric acid. Monitoring of salicylate and its metabolites is of toxicological, pharmacological and biomedical interest. Three capillary electrophoresis (CE) methods featuring alkaline aqueous buffers, laser-induced fluorescence (LIF) detection and no solute extraction or derivatization have been explored. A competitive binding, electrokinetic capillary-based immunoassay is developed that recognizes the presence of salicylate and gentisic acid in urine. Differentiation of the two compounds, however, is problematic. With appropriate ultraviolet excitation, many salicylate-related compounds are fluorescent so that CE with direct urine injection and LIF detection permits the determination of salicylate, gentisic acid and salicyluric acid. Using a HeCd laser with 325 nm produces interference-free monitoring of all three compounds. Using 257 nm excitation from a frequency doubled Ar ion laser, native fluorescence of an endogenous urinary compound that co-migrates with gentisic acid is observed. With wavelength-resolved fluorescence detection, however, the two substances are distinguished. Furthermore, this technique, with comparison to literature data, permits the putative assignment of several peaks to other salicylate metabolites, namely glucuronide conjugates of salicylate and salicyluric acid. All three CE-LIF techniques have been applied to toxicological patient urines and urines collected after ingestion of 500 mg acetylsalicylic acid. CE results compare favorably with those obtained by a commercial fluorescence polarization immunoassay and by a conventional photometric assay.
KW - Gentisic acid
KW - Salicylate
KW - Salicyluric acid
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U2 - 10.1016/S0378-4347(00)00507-7
DO - 10.1016/S0378-4347(00)00507-7
M3 - Article
C2 - 11254191
AN - SCOPUS:0035809816
VL - 752
SP - 17
EP - 31
JO - Journal of Chromatography B: Biomedical Sciences and Applications
JF - Journal of Chromatography B: Biomedical Sciences and Applications
SN - 1387-2273
IS - 1
ER -