flow Cells See LEDspec on page 192 See Mini★Star on page 168 Liquid Waveguide Capillary Cell SPECTROSCOPY Liquid Waveguide Capillary Cells (LWCC) are fiber optic cells that combine an increased optical pathlength (50–500 cm) with small sample volumes (125–1250 mL). They can be connected via optical fibers to a spectrophotometer with fiber optic capabilities. Ultra-sensitive absorbance measurements can be performed in the ultraviolet (UV), visible (VIS) and near-infrared (NIR) to detect low sample concentrations in a laboratory or process control environment. According to Beer’s Law the absorbance signal is proportional to chemical concentration and light path length. Compared with a standard 1 cm cell, a 1 mAU signal is enhanced fifty-fold with a 50 cm cell to 50 mAU, using WPI’s patented aqueous waveguide technology*. The LWCC can be connected directly to a pump or can even be filled using a syringe. Based on fiber optics, the LWCC is designed for use with WPI’s LEDspec photometric detector (see pages 192-193). Pathlength, internal volume, and wavelength range (measured with ultrapure water and a Tidas II spectrophotometer Pathlength [cm] LWCC-3050 LWCC-3100 LWCC-3250 LWCC-3500 50 100 250 500 internal Volume [µL] 125 250 500 1250 Wavelength Range [nm] measured with Tidas II 230-800 230-730 250-730 280-730 LWCC Key features Typical Efficiency Curves for LWCC Percent Transmission (%T) 50 40 30 20 10 0 200 Pathlength 50cm 100cm 250cm LWCC SPECifiCAtiOnS WAVEGUIDE MATERIAL OPTICAL PATHLENGTH INNER DIAMETER INTERNAL VOLUME SAMPLE INLET/OUTLET COMPRESSION FITTING FIBER INPUT MINIMUM PRESSURE* SOLVENT RESISTANCE SHIPPING WEIGHT Fused silica tubing coated with a low refractive index polymer 50-500 cm 550 μm ≈ 5 - 1250 μL 1/16”, 1/32” SMA, ID = 400 μm 1.5 - 3 PSI Most organic & inorganic solvents 1.4 kg (3 lb) 300 400 500 600 700 800 900 Wavelength (nm) These spectra show the optimal detection limits for LWCCs of varying pathlength. World Precision Instruments UK: Tel: +44 (0)1462 424700 • wpiuk@wpi-europe.com *A one-meter Type II waveguide of 550 µm ID requires about 1.5 PSI for water flow of 1 mL/min. 200 www.wpiinc.com Germany: Tel: +49 (0)30-6188845 • wpide@wpi-europe.com US: Tel: 941-371-1003 • sales@wpiinc.com