Capillary electrochromatography (CEC) is a method of separating small particles based on their size and electrical charge. It can be used to determine the amount of proteins, drugs, hormones, toxins, and other substances in a liquid sample, such as blood or urine.


  This relatively new method is capable of separating molecules that differ by just one very small change in their structure, which may affect how the molecule functions within the body.

It is also capable of testing very small samples and can be performed more rapidly than older methods.


  Medical laboratories use CEC to measure levels of substances in blood and urine testing. For instance, CEC can be used to detect the levels of prescription or illegal drugs in the body.


  Pharmaceutical companies use CEC to perform chiral separation. Chiral molecules are two molecules created from the same building blocks but are mirror images of each other

. Many drugs are initially developed as a mixture of two chiral molecules, but often one of the molecules is more useful in the human body than the other. The reason for this probably has to do with how the shape of the molecule affects its interactions with cells in the human body.


CEC can be used to separate chiral molecules so that only the most beneficial form is packaged into a drug. Examples of drugs that can be separated by CEC include escitalopram (Lexapro®) and citalopram (Celexa®), two antidepressant medications that are chiral molecules.

الله يعطيك العافية عالموضوع

بس كأنو بكير...........ما

بس كيف هالطريقة بتفصل المركبات اليدوية chiral

مع أنو نفس الكتلة و التركيب و كل شي

بس التوضع الفراغي مختلف
                                                                                                             
                                                                                                   
                                                                                                 

Capillary electrochromatography (CEC) is an analytical method of growing interest to the pharmaceutical industry. Because CEC is a combination of high-performance liquid chromatography (HPLC) and capillary electrophoresis (CE) it has the advantages of the high selectivity of HPLC and the high efficiency of CE.



The capillaries can be packed with different packing materials. The mixed-mode phase consisting of a strong cation exchanger and alkyl chains on the silica surface has some advantages over conventional reversed-phase (RP) packing materials. In this article the authors describe the use of CEC to separate the active ingredients and preservatives in creams from different manufactures. On the basis of the high efficiency of CEC it was possible to develop one isocratic method for all the compounds in the different samples. The method was validated with regard to identification, reproducibility, linearity, limit of detection, and quantitation.

شكراً آيرون مان عالمعلومات المفيدة

بس ياترى هالجهاز كيف شكله

يعني شي غريب إنو نجمع بين الاستشراب و الرحلان الكهربائي....

و ياريت إذا في معلومات أكتر عن هالجهاز تزودنا فيها....

و دائماً هيك نزلنا مقالات تحليلية...

اقتباس

بس كيف هالطريقة بتفصل المركبات اليدوية chiral

مع أنو نفس الكتلة و التركيب و كل شي

بس التوضع الفراغي مختلف

Current chiral HPLC
methods are either direct, which utilizes chiral stationary phases (CSPs) and chiral 

additives in the mobile phase, or indirect, which involves derivatization of samples.
Direct chiral separations using CSPs are more widely used and are more predictable, in
mechanistic terms, than those using chiral additives in the mobile phase23.

However, there is no single CSP that can be considered universal, i.e., has the
ability to separate all classes of racemic compounds. Choosing the right CSP for the
enantioseparation of a chiral compound is difficult. The decision relies mostly on
empirical data22-23.

An alternative way of choosing a CSP is by using predictive empirical rules that have been developed based on empirical structures 24-26
All three components, analyte, CSP, and mobile phase, must be taken into
consideration when developing a chiral separation method.

Examples of the CSPs used for the separations of profens
with normal phase eluents are the derivatized polysaccharides72-81 adsorbed on
macroporous silica gel such as Chiralcel OD, Chiralcel OJ, and Chiralpak AD

اقتباس

بس ياترى هالجهاز كيف شكله 

يعني شي غريب إنو نجمع بين الاستشراب و الرحلان الكهربائي....

التقنية بتشبه HPLC بس الحركة تتم عن طريق EOF 

آيرن مان



ما طلعت الصورة.....    


ياريت تجرب طريقة تانية لوضعها.....


و شكراً كتيـــــــــــــــــر....