Electron-capture gas chromatographic determination of cyanide, iodide, nitrite, sulfide, and thiocyanate anions by phase-transfer-catalyzed derivatization with pentafluorobenzyl bromide.

A sensitive gas chromatographic method has been established for the simultaneous determination of biologically active inorganic anions, including cyanide, iodide, nitrite, sulfide, and thiocyanate anions as their volatile organic derivatives. The method is based on the formation of ion pairs from the anions and a complex cryptand and on the resulting neutral ion-pair partition to an organic phase for derivatization with pentafluorobenzyl bromide. Several parameters affecting the partition and derivatization of the anions were investigated. Individual and simultaneous determination of the anions can be achieved at sub-nmol levels with an electron-capture detector. Partial application of the method for the analysis of cyanide, nitrite, and thiocyanate in real samples proved satisfactory.

Determination of thiocyanate anion by high-performance liquid chromatography with fluorimetric detection.

A simple and sensitive high-performance liquid chromatographic (HPLC) method was established for the trace determination of thiocyanate anion as a fluorogenic derivative. The method is based on the chemical derivatization of thiocyanate anion with 3-bromomethyl-7-methoxy-1,4-benzoxazin-2-one. The resulting derivative was separated by a Nova-Pak C18 reversed-phase column. Optimization conditions for the derivatization of thiocyanate anion were investigated by HPLC with fluorimetric detection. The linear range for the quantitation of thiocyanate anion was 1-0.05 nmol in 0.1 mL of sample; the detection limit (with a signal-to-noise ratio of 5) of a 20-microL injected aliquot was approximately 3.3 +/- 1.2 fmol. Application of the method to the analysis of thiocyanate anion in saliva and plasma proved to be feasible.

Determination of thiocyanate anion as an organic derivative by gas chromatography.

A simple and sensitive gas chromatographic method has been established for the determination of biologically active thiocyanate anion as pentafluorobenzyl thiocyanate. The method is based on the partition of an ion-pair from the thiocyanate anion and a complex crypstand to a benzene layer for derivatization with pentafluorobenzyl bromide. The resulting derivative was analyzed by gas chromatography with electron capture detection. The quantitation range for thiocyanate anion was over 0.086 and 3.45 nmol. The detection limit of thiocyanate in 0.2 ml sample is about 34 pmol. The effects of several parameters such as base or acid, reaction time and the amount of pentafluorobenzyl bromide were evaluated for the optimization of partition and derivatization of thiocyanate anion. Application of the method to the analysis of thiocyanate in waste water and human saliva proved to be feasible.