A fully validated isotope dilution HPLC-MS/MS method for the simultaneous determination of succinylcholine and succinylmonocholine in serum and urine samples

Abstract The choriogonadotropin beta-subunit radioimminoassay has been used extensively to measure human choriogonadotropin in the sera of pregnant women and individuals with trophoblastic and nontrophoblastic tumors. Unmodified, this method cannot be used to measure choriogonadotropin in urine because of interfering substances. We circumvented the non-parallelism between the standards and serial dilutions of urine containing choriogonadotropin by adding pooled urine from men to the standard tubes and limiting the volume of urine to 100 microliter. This modified assay has a sensitivity of 3 int. units/liter of urine and is specific for choriogonadotropin concentrations of 40 int. units/liter of urine. Analytical recovery of choriogonadotropin added to urine ranged from 96 to 105%. The within-assay CV was 7.6%; the between-assay CV was 11.8%. Concentrations of choriogonadotropin in concurrently collected serum and urine samples from pregnant women correlated well. The test can be performed within 24 h by using the double-antibody method for separating bound from free hormone, or in 3 h with a dioxane method. The assay is about 20-fold more sensitive than the 2-min or 2-h slide and tube pregnancy tests, and seven-to 12-fold more sensitive than the radioreceptor assay.

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Spectrophotometric determination of methimazole in pharmaceutical, serum and urine samples by reaction with potassium ferricyanide-Fe(III)

Journal of Analytical Chemistry ◽

10.1134/s1061934810070099 ◽

2010 ◽

Vol 65 (7) ◽

pp. 707-712 ◽

Cited By ~ 14

Author(s):

Chunhong Dong ◽

Yan Zhang ◽

Li Guo ◽

Quan-min Li

Keyword(s):

Spectrophotometric Determination ◽

Potassium Ferricyanide ◽

Urine Samples ◽

Serum And Urine ◽

Serum And Urine Samples

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Maltotetraose as a substrate for enzyme-coupled assay of amylase activity in serum and urine.

Clinical Chemistry ◽

10.1093/clinchem/25.3.481 ◽

1979 ◽

Vol 25 (3) ◽

pp. 481-483 ◽

Cited By ~ 16

Author(s):

K J Whitlow ◽

N Gochman ◽

R L Forrester ◽

L J Wataji

Keyword(s):

Amylase Activity ◽

Biological Fluids ◽

Urine Samples ◽

Coupled Assay ◽

Serum And Urine ◽

Serum And Urine Samples

Abstract The use of maltotetraose ss a new substrate for the enzyme-coupled determination of amylase activity in biological fluids was developed by Beckman Microbics. We evaluated a manual and a centrifugal analyzer version of the method in comparison with two commonly used manual starch-dye amylase techniques: Roche Amylochrome and Pharmacia Phadebas. Both maltotetraose amylase procedures proved to be rapid and precise, and results correlated satisfactorily with the starch-dye methods for serum and urine samples.

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Nonenzymatic stopped-flow fluorimetric method for direct determination of uric acid in serum and urine.

Clinical Chemistry ◽

10.1093/clinchem/35.2.230 ◽

1989 ◽

Vol 35 (2) ◽

pp. 230-233 ◽

Cited By ~ 6

Author(s):

D Pérez-Bendito ◽

A Gómez-Hens ◽

M C Gutiérrez ◽

S Antón

Keyword(s):

Hydrogen Peroxide ◽

Uric Acid ◽

Direct Determination ◽

Urine Samples ◽

Stopped Flow ◽

Fluorimetric Determination ◽

Kinetic Measurements ◽

Serum And Urine ◽

Serum And Urine Samples

Abstract A simple, direct, sensitive, and selective stopped-flow method for the fluorimetric determination of uric acid in serum and urine samples is described. The variation of fluorescence intensity during the reaction between uric acid and 1,1,3-tricyano-2-amino-1-propene (triap) in the presence of hydrogen peroxide is monitored. For these kinetic measurements peroxide is monitored. For these kinetic measurements we used a versatile stopped-flow module that can be fitted to any fluorimeter. The linear range of the proposed method is 0.08-3.00 mg of uric acid per liter, and the detection limit is 0.03 mg/L. Within- and between-assay CVs and selectivity data are reported. Results for serum and urine samples correlated well with those obtained by the uricase method The proposed method is inexpensive and requires no sophisticated detection equipment.

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