title: Chromatographic separation of clenbuterol by bonded phases bearing nano-baskets of p-tert-calix[4]-1,2-crown-3, -crown-4, -crown-5 and -crown-6.
abstract: BACKGROUND
  Clenbuterol (salbutamol), which increases muscle mass and decreases adipose tissue, is misused as a nutrient-repartitioning agent in livestock. In this paper a new sensitive method for determining clenbuterol in livestock is presented. The novelty of this approach is the separation and determination of salbutamol enantiomers with marked quantitative merits.
  
  
  RESULTS
  Four proton di-ionisable Nano-baskets, namely 5,11,17,23-tetrakis(1,1-dimethylethyl)-25,26-bis(carboxy-methoxy)calix[4]arene-27,28-crown-3, -crown-4, -crown-5 and -crown-6 in the cone conformation, were synthesised and used to prepare bonded phases for high-performance liquid chromatography separation. The new synthesised bonded phases were characterised and optimised. The bonding interactions of solute/bonded phases were examined and the main interactions are reported.
  
  
  CONCLUSIONS
  The clenbuterol levels in six samples of livestock meat (pork, pork casing, beef, beef casing, mutton and mutton casing) were analysed and the results revealed that for the best bonded phases the limits of detection and quantitation were 0.06 and 0.2 µg mL(-1) respectively.
authors.affiliation: Department of Chemical Engineering, Shahreza Branch, Islamic Azad University, Shahreza, Iran.
authors.forename: Bahram
authors.initials: B
authors.lastname: Mokhtari
authors.forename: Kobra
authors.initials: K
authors.lastname: Pourabdollah
mesh_terms: D000318:Adrenergic beta-Agonists; D000420:Albuterol / Q000032:analysis*; D000818:Animals; D047250:Calixarenes / Q000737:chemistry*; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002976:Clenbuterol / Q000032:analysis*; D043844:Crown Ethers / Q000737:chemistry*; D005506:Food Contamination / Q000517:prevention & control*; D007536:Isomerism; D057230:Limit of Detection; D058751:Livestock; D008460:Meat / Q000032:analysis*; D008461:Meat Products / Q000032:analysis; D012756:Sheep; D013552:Swine
chemical_list: D000318:Adrenergic beta-Agonists; D043844:Crown Ethers; D047250:Calixarenes; D000420:Albuterol; D002976:Clenbuterol