Amino Acids and Catecholamines Analysis in Microdialysates
High speed, sensitive and small sample needs for separation of primary amino acids and catecholamines
This method couples capillary electrophoresis separation with LIF detection to provide the analyst with a selective and sensitive tool for the analysis of biological samples.
Since the quantification method requires less than 1 µL of sample, neurochemist can increase the number of tests on the same sample to provide other analytical data with complementary methods.
Primary amino acids and catecholamines separate in a single run
Limit of detection :
- Glutamate: 6.8 x 10-10 mol/L (2.2 x 10-17 moles)
- Gaba: 6.4 x 10-10 mol/L (2.0 x 10-17 moles)
- Aspartate: 9.0 x 10-10 mol/L (2.9 x 10-17 moles)
(LOD calculated for a S/N ratio of 3)
Run time : 16 minutes
Sample injection of 32 nl
(microdialysate diluted 1/5)
NDA labelling reagent:
NDA is a fluorogenic dye which fluoresces weakly in its native form but has a good fluorescent yield when reacted with CN- and a primary amine.
Such derivatives are excitable at 410 nm or 442 nm, using respectively diode or HeCd lasers.
Derivatization procedure: refer to TN002
Instruments | Capillary Electrophoresis: Agilent 3D CE Detector: Picometrics ZETALIF LASER detector Laser: Diode laser, 410 nm, 10 mW |
Samples | Standards : 10-7 M (labelled at 10-6 M and diluted 10 times prior to injection) Microdialysate: diluted 5 times in distilled water |
Methods | Capillary: 50 µm ID, 65 cm length (50 cm effective length) Standard Injection : 10 seconds at 50mbar, i.e. 14.8 nL injected (working temp. 25°C) Microdialysate Injection: 15 seconds at 0.7 PSI, i.e. 32 nL injected. |
