• 主页
  • 查找结果
  • Exploring the possibilities of capacitively coupled contactless conductivity detection in combination with liquid chromatography for the analysis of polar compounds using aminoglycosides as test case.

Exploring the possibilities of capacitively coupled contactless conductivity detection in combination with liquid chromatography for the analysis of polar compounds using aminoglycosides as test case.

Journal of pharmaceutical and biomedical analysis (2015-01-01)
Péter Jankovics, Shruti Chopra, Mohamed N El-Attug, Deirdre Cabooter, Kris Wolfs, Béla Noszál, Ann Van Schepdael, Erwin Adams
摘要

The analysis of highly polar (often charged) compounds which lack a strong UV absorbing chromophore is really challenging. Despite the numerous analytical methods published, the demand for a simple, robust and cheap technique for their analysis still persists. Here, reversed phase (RP) liquid chromatography (LC) with capacitively coupled contactless conductivity detection (C(4)D) was explored for the first time as a possible method for separation and detection of various aminoglycoside (AMG) antibiotics which were taken as typical test compounds: tobramycin (TOB), spectinomycin, streptomycin, amikacin, kanamycin A and kanamycin B. C(4)D was performed using a commercially available as well as a laboratory made cell. As ion-pairing reagents (IPR) four perfluorinated carboxylic acids were used: pentafluoropropionic acid, heptafluorobutyric acid, nonafluoropentanoic acid (NFPA) and pentadecafluorooctanoic acid (PDFOA). 0.125 mM NFPA-acetonitrile (ACN) (90:10) or 0.125 mM PDFOA-ACN (70:30) as mobile phases were suitable to detect TOB with reasonable retention times. However, NFPA was preferred for practical reasons. Its applicable concentration range in the mobile phase was strongly restricted by loss of chromatographic performance at lower levels and excessive background conductivity at higher levels. Overall repeatability and robustness of the method were rather poor which was explained by the relatively low IPR levels. Selectivity between the tested AMGs was mainly influenced by the number of protonated amino groups per molecule making it impossible to separate compounds of equal net charges. Problems encountered with gradient elution, hydrophilic interaction liquid chromatography (HILIC) and separation at high pH without IPRs are also discussed.

材料
货号
品牌
产品描述

Sigma-Aldrich
乙腈, anhydrous, 99.8%
Sigma-Aldrich
氢氧化钠 溶液, BioUltra, for molecular biology, 10 M in H2O
Sigma-Aldrich
氢氧化钠 溶液, 1.0 N, BioReagent, suitable for cell culture
Sigma-Aldrich
全氟丁酸, 98%
Sigma-Aldrich
乙腈 溶液, contains 0.1 % (v/v) trifluoroacetic acid, suitable for HPLC
Sigma-Aldrich
全氟辛酸, 95%
Sigma-Aldrich
乙酸, natural, ≥99.5%, FG
Sigma-Aldrich
L-苏氨酸, reagent grade, ≥98% (HPLC)
Sigma-Aldrich
L-苏氨酸, from non-animal source, meets EP, JP, USP testing specifications, suitable for cell culture, 99.0-101.0%
Sigma-Aldrich
DL-甲硫氨酸, ≥99%
Sigma-Aldrich
五氟丙酸, 97%
Sigma-Aldrich
乙腈 溶液, contains 0.1 % (v/v) formic acid, suitable for HPLC
Sigma-Aldrich
全氟戊酸, 97%
Sigma-Aldrich
七氟丁酸, ≥99.0% (GC)
Sigma-Aldrich
乙腈, HPLC Plus, ≥99.9%, poly-coated bottles
Sigma-Aldrich
乙酸, ≥99.5%, FCC, FG
Sigma-Aldrich
5α-二氢睾酮, ≥97.5%
Sigma-Aldrich
乙酸, for luminescence, BioUltra, ≥99.5% (GC)
Sigma-Aldrich
氢氧化钠, BioUltra, for luminescence, ≥98.0% (T), pellets
Sigma-Aldrich
氢氧化钠, ultra dry, powder or crystals, 99.99% trace metals basis
Sigma-Aldrich
L-苏氨酸, BioXtra, ≥99.5% (NT)
SAFC
L-苏氨酸
Sigma-Aldrich
DL-缬氨酸, ReagentPlus®, ≥99.0% (NT)
Sigma-Aldrich
DL-甲硫氨酸, BioReagent, suitable for cell culture, suitable for insect cell culture, ≥99%
Sigma-Aldrich
乙腈, electronic grade, 99.999% trace metals basis
Sigma-Aldrich
DL-亮氨酸, ≥99% (HPLC)
Sigma-Aldrich
乙腈 溶液, contains 0.05 % (w/v) ammonium formate, 0.1 % (v/v) formic acid, 5 % (v/v) water, suitable for HPLC
Sigma-Aldrich
DL-甲硫氨酸, 99%, FCC, FG
Sigma-Aldrich
乙腈, ≥99.5%, ACS reagent
Sigma-Aldrich
3-乙基-2,4-戊二酮,互变异构体的混合物, 98%