Liquid Waveguide Capillary Cells
Liquid Waveguide Capillary Cells (LWCC) are optical sample cells that combine an increased optical pathlength (2 –100 cm) with small sample volumes (5 – 1250 µL). 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, a chromatography column, or can even be filled using a syringe. Modular-based sample systems can be assembled using WPI’s PDA TIDAS I, TIDAS II or CCD, SpectraUSB based spectrometer modules and WPI’s range of UV/VIS light sources D2H, D2Lite™, and FO-6000.
References
Sample Absorbance Spectra
LWCC Specifications
LWCC Key features
Related Patents

1. Micro Chemical Analysis Employing Flow Through Detectors, 1995, U.S. Patent No. 5,444,807.

2. Aqueous Fluid Core Waveguide, 1996, U.S. Patent No. 5,507,447.

3. Long Capillary Waveguide Raman Cell, 1997, U.S. Patent No. 5,604,587.

4. Chemical Sensing Techniques Employing Liquid-Core Optical Fibers, U.S. Patent No. 6,016,372

Applications

LWCCs have been used in a variety of applications, such as liquid chromatography detection and stopped-flow detection, drinking water analysis, as well as environmental and oceanographic monitoring systems (see References). To exemplify the capabilities of the LWCC, absorbance spectra of Bovine Serum Albumin (BSA) dissolved in a phosphate buffer were measured in a LWCC-2 with 50 cm optical pathlength. The absorbance spectra were acquired with a TIDAS II (TIDAS-BASIC) and a 50 cm LWCC of Type II (LWCC-2). The liquid samples were drawn into the LWCC with a liquid injector assembly (WPI #58006) and a Peri-Star™ peristaltic pump (WPI #500291).
WPI's Liquid Waveguide Capillary Cells are made of fused silica tubing with an outer coating of a low refractive index polymer. This results in high signal stability and easy removal of air bubbles trapped in the sensor cell due to the hydrophilic character of the cell wall.
These unique instruments were invented, patented and optimized by WPI during the last seven years of research in this field*. They feature a number of advantages over conventional absorbance cells and flow cell arrangements. Designed for use with fiber optics, they require only small sample volumes and have a high optical throughput.
Order Numbers
LWCC-2002 Liquid Waveguide Capillary Cell, pathlength = 2 cm
LWCC-2005 Liquid Waveguide Capillary Cell, pathlength = 5 cm
LWCC-2010 Liquid Waveguide Capillary Cell, pathlength = 10 cm
LWCC-2050 Liquid Waveguide Capillary Cell, pathlength = 50 cm
LWCC-2100 Liquid Waveguide Capillary Cell, pathlength = 100 cm
LWCC-2200 Liquid Waveguide Capillary Cell pathlength = 200 cm
LWCC-2500 Liquid Waveguide Capillary Cell pathlength = 500 cm
Accessories


A sample injector assembly can be used to conveniently fill an LWCC with sample solution using a peristaltic pump. Please note that the LWCC requires 2 optical fibers to connect to spectrophotometer system. Choose between anti-solarized 400 micron core or UV-enhanced cables (may be ordered in 1 or 3 meter lengths).
58006 Sample Injector Assembly
500291 Peri-Star™ Peristaltic Pump, 6 roller for smooth liquid injection (110V)
FO-400-SMA1M Fiber Optic cable, 1 m, SMA, 400 µm core, UV-enhanced, 2 required
501609 Waveguide Cleaning Kit MSDS
KITLWCC LWCC Start-up Kit, includes FO-400 SMA 1 M (two), 58006, 500291, 501609
DOWN LOAD WPI'S LWCC DATA SHEET