MicroVette™
MicroVette™ is a UV/VIS optical sample cell for microliter volumes. The cell combines the technology of a micro-colorimeter developed by Dr. G. L. Vogel (American Dental Association Health Foundation) with WPI's proprietary Liquid Waveguide Capillary Cell (LWCC). Only 4 microliters of fluid sample are required to achieve a 23 mm long light pathlength. The cell is loaded by placing the sample onto the sample well using a regular 10 microliter pipette. The sample is introduced into the cell by capillary action. After each measurement, the sample is flushed out by vacuum suction. A drop of acetone cleans and dries the cell for the next measurement. The complete process takes less than one minute. With the current platform, the cell can be built to match a customer’s specification. Pathlength can vary from 23 mm (4 microliters sample) to 100 mm (15 microliter sample).
Two fiber optic cables are used to connect the MicroVette to a spectrophotometer. The launch cable is used to couple light from a light source to the sample chamber, which is designed using waveguide principles. The return guides the light from the sample chamber to a spectrophotometer. The MicroVette is ideally suited for measurements with WPI spectrophotometers (TIDAS II) and spectrometer modules (PDA , (TIDAS I) and CCD, SpectraUSB and light sources (D2H, D2Lite™).
To exemplify the performance of the MicroVette, Bovine Serum Albumin (BSA) dissolved in a phosphate buffer BSA has been analyzed in a MicroVette with a 10 cm optical pathlength. Absorbance spectra and a calibration curve are shown. Each spectra has been obtained from a sample volume of 15 µL.
A vacuum source that can produce greater than -5 psi of vacuum is needed to unload the cell. A liquid trap assembly, consisting of a liquid trap, silicon tubing and a low-noise vacuum pump can be used to conveniently remove the sample from the MicroVette.
MICROVETTE SPECIFICATIONS
Wavelength range 200 nm-1000 nm
Linear range 0 - 2.0 AU minimum
Transmission at 550 nm 20%*
Transmission at 250 nm 16%*
Cuvette volume/pathlength 4 µl/23 mm (minimum), for each additional µl of sample, the pathlength increases by 7 mm. Maximum is 15 µl at 100 mm.
Fiber optic connections SMA 200 µm
* using 200 micron core fiber as 100% transmission reference
MICROVETTE MicroVette Optical sample Cell
Specify pathlength when ordering
.OPTIONAL ACCESSORIES
58200 Liquid Trap Assembly
501609 Waveguide Cleaning Kit
LV 140-Y Vacuum Pump (120 V)
LV 140 - Z Vacuum Pump (240 V)
FO-200AS-SMA Fiber Optic Cable, 1m, SMA, 200 µ core, anti-solarization, 2 required
KITMV MicroVette Start-up Kit includes Liquid Trap Assembly, Waveguide Cleaning Kit, two fiber optic cables and vacuum pump
References