Identification of Ɛ-Caprolactam and Melamine in Polyvinyl- Pyrrolidone Powder by Double Injection Micellar Elektrokinetic Chromatography

Abstract

A double-injection micellar electrokinetic chromatography (DIMEKC) method for the identification of Ɛ-caprolactam and melamine deliberately added to povidone (polyvinylpyrrolidone) products has been developed. The separations were performed in 89 mM phosphate buffer (pH 7.4) containing 52 mM sodium dodecyl sulfate (SDS) in fused silica capillaries with UV absorption detection at 200 nm. The identification relied on the agreement between the calculated migration time (t mig(c) ) of the analytes and the migration time (t mig ) of their corresponding reference standards being analysed simultaneously within a double injection run. The migration time of the analytes was calculated from the partial migration times (t mig(p) ) as described in this paper. The migration time ratios (t mig(c) / t mig ) varied between 0.997 and 1.005 (i.e., 1.001 ± 0.004), indicating good agreement between the observed and calculated migration times. Identification of Ɛ-Caprolactam and Melamine in Polyvinyl-

Double‐injection capillary electrophoresis for the identification of analytes

“…A mixture of povidone, melamine, paracetamol, and caprolactam was analyzed in double injection SDS micellar EKC mode [16], Fig. 2.…”

“…The t PE was 1.0 min (t ramp = 0.1 min; n = 4). Coffee, tea, Treo, Koffein Recip, and Panodil tabelts were analyzed at the same conditions as those in Table 1 [16]. Somatropin (hGH) was analyzed at 30°C in a 60 × 70 cm × 50 m double coated capillary (Polybrene/Chondroitin sulfate A) using 100 mM ammonium phosphate (pH 6.0) as BGE.…”

Identification of human chorionic gonadotropin hormone in illegally distributed products by MALDI-TOF mass spectrometry and double-injection capillary zone electrophoresis

“…It is to be noted that variations in the migration time differences, being used for the migration time calculations, will be signicantly smaller than variations in the migration times. 24 Variations in the migration time differences were determined to be less than 1.0%. It is to be noted that the type of capillary coating can affect the precision of the EOF and migration times.…”