Cerium (IV)-Based Chemiluminescence Analysis of Analgin

Non-covalent binding and selective fluorescent sensing of dipyrone with a carbocyanine dye and cetyltrimethylammonium bromide

The work is aimed at the search of selective fluorescent sensors without using specific artificial receptors, antibodies, enzymes etc. With this end in view, methods based on non-covalent binding of target analytes are sought. We observed dramatic changes in the emission spectrum of a carbocyanine dye in a micellar surfactant solution (cetyltrimethylammonium bromide, CTAB) in the presence of dipyrone (metamizol, analgin): the 480 nm band intensity increases with a simultaneous decrease in intensity in near-IR region (720 nm). MALDI and NMR-¹H data show the intact molecules of dipyrone and the dye. The detection can be performed in the presence of other organic species and inorganic salts. Dipyrone testing is feasible within 5 × 10^-7-5 × 10^-4M with RSDs of 3.5% by using a visualizer instead of a spectrofluorimeter.

Use of an immiscible diluent in ionic liquid / ion pair LC for the assay of an injectable analgesic

Injectable solutions used in treatment of intense pain are based on combinations of active ingredients such as metamizole sodium (MTZ), pitofenone hydrochloride (PTF) and fenpiverine bromide (FPB). The simultaneous chromatographic assay of such combinations poses difficulties due to their structural variety, highly polar character, and wide concentration ranges (500 mg mL−1 for MTZ, 2 mg mL−1 for PTF and 0.02 mg mL−1 for FPB). Fast hydrolysis of MTZ on aqueous dilution causes additional problems due to impurity (MTC) formation. Sodium hexane sulphonate (10 mM) was used as ion pairing agent for PTF, FPB and MTC in a mobile phase consisting of 48/52 (v/v) methanol and aqueous 0.2% triethylamine at pH=3. The ionic liquid 1-butyl-1-methyl-pyrrolidinium tetrafluoroborate (10 mM) was used as mobile phase additive to preserve the MTZ peak symmetry. The minor active ingredient FPB was selectively extracted into 1-octanol by ion pair formation with picric acid. A 20 µL aliquot of the organic layer was directly injected into the column.

In vitro monitoring sub-nanogram amounts analgin in human urine by its inhibitory of the luminol-periodate chemiluminescence reaction using reagent immobilization release technique

A selective and sensitive as well as rapid chemiluminescence (CL) flow sensor for the determination of analgin is described. The analytical reagents involved in chemiluminescence reaction, luminol and periodate, were both immobilized on an anion-exchange column. The CL signals produced by the reaction between luminol and periodate, which were eluted from the column through water injection, were decreased in the presence of analgin. Analgin was sensed by measuring the decrement of CL intensity, and which was observed linear over the logarithm of analgin concentration range of 0.1 to 50.0 ng mL(-1), and the limit of detection was 0.04 ng mL(-1) (3ó). At a flow rate of 2.0 mL min(-1), including sampling and washing, the detection could be performed in 0.5 min with a relative standard deviation of less than 3.0%. The proposed procedure was applied successfully in the monitoring of analgin in human urine samples without any pre-treatment process. It was found that the analgin concentration reached its maximum after being orally administrated for 4 h, and the analgin metabolism ratio in 10 h was 9.28% in the body of volunteers. The flow sensor offered reagentless procedures and remarkable stability in determination of analgin, and could be easily reused over 80 h.

Analytical applications of flow injection with chemiluminescence detection--a review

This paper reviews the literature on analytical applications of flow injection (FI) techniques with chemiluminescence (CL) detection from 1995-1999. The focus is on the application of FI-CL to the quantitative determination of specific analytes in real sample matrices. Therefore, entries have been tabulated under the most appropriate application area, ie pharmaceutical, environmental, foods and beverages and biomedical, as defined by the matrix that has been analysed. Each table lists analytes alphabetically and gives details of the exact sample matrix, the limit of detection (as reported in the original paper) and comments on the CL reaction used.