Strong anion exchange

In another example, a multiresidue method using HPLC/ESI-MS was developed to determine six imidazolinone herbicides in five different soil types. Good recoveries (80-120%) and adequate sensitivity at the 2.0 ngg level were obtained for the compounds investigated. In the method, a 50-g soil sample was extracted for 1 h in 0.5N NaOH solution. A portion of the extract was acidified, to precipitate the humic acids, and the supernatant was then loaded on to a preconditioned trifunctional Cig SPE cartridge and eluted with ethyl acetate. Further cleanup was achieved using a tandem strong anion-exchange (SAX)-SCX SPE combination. Analytes were eluted... 

Anions Column packed with anionic luminol derivative bound to a strong anion-exchange resin, displaced derivative-H202-[Fe(CN)6]3- CL 1.0 pM SO42--5.0 pM Br" 34... 

Smith et al (76,773 analyzed hydralazine in a drug mixture containing hydralazine hydrochloride, hydrochlorothiazide, and an impurity derived from the latter. The column was 1 m x 2.1 mm (ID) stainless steel, packed with a strong anion exchanger on 30 Jm Zipax . The mobile phase was pH 9 2 borate buffer containing 0.005M sodium sulfate (5 methanol), at 1.7 ml per minute. Detection was by ultraviolet absorption at 25 nm. 

A high-performance liquid chromatographic method for nalidixic acid on a strong anion-exchange resin column has been reported, using a mobile phase of 0.01 M sodium tetraborate at pH 9.2 and 0.003 M sodium sulfate. The relative retention time for nalidixic acid in the system reported by Sondach and Koch was 0.86 with sulfanilic acid as the standard at... 

Wang J, Ashley K, Marlow D, England EC, Carlton G. Field method for the determination of hexavalent chromium by ultrasonication and strong anion-exchange solid-phase extraction. Anal. Chem. 1999 71 1027-1032. 

---