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Instrumenting scientific ideas
WORLD
PRECISION
INSTRUMENTS
LWCC-M-xxx
Measure low volume samples with UV/VIS
absorbance spectroscopy
Serial No._____________________
www.wpiinc.com
INSTRUCTION MANUAL
111717
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LWCC-M
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CONTENTS
ABOUT THIS MANUAL ................................................................................................................... 1
INTRODUCTION .............................................................................................................................. 1
General Warnings and Cautions ........................................................................................... 2
INSTRUMENT DESCRIPTION ........................................................................................................ 2
Parts List ...................................................................................................................................... 2
Unpacking ................................................................................................................................... 2
Hardware Description .............................................................................................................. 3
Required But Not Provided (see Accessories) .............................................................. 3
Assembly ............................................................................................................................... 3
OPERATING INSTRUCTIONS ......................................................................................................... 4
Transmission Verication ........................................................................................................ 4
Noise Determination ................................................................................................................ 4
Refractive Index ......................................................................................................................... 4
Measuring in a Continuous Flow ........................................................................................... 5
Measuring Discrete Samples with WPI’s Injection System .............................................. 5
INSTRUMENT MAINTENANCE ...................................................................................................... 6
Standard Cleaning .................................................................................................................... 6
Advanced Cleaning .................................................................................................................. 6
Storage ........................................................................................................................................ 7
ACCESSORIES................................................................................................................................... 7
TROUBLESHOOTING ..................................................................................................................... 8
Typical Contamination Eects ................................................................................................ 8
Additional Information on Contamination .......................................................................... 9
SPECIFICATIONS ............................................................................................................................ 10
Related Patents .......................................................................................................................10
INDEX ............................................................................................................................................... 11
WARRANTY .....................................................................................................................................12
Claims and Returns ................................................................................................................12
Copyright © 2017 by World Precision Instruments, LLC. All rights reserved. No part of this publication
may be reproduced or translated into any language, in any form, without prior written permission of
World Precision Instruments, Inc.
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LWCC-M
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ABOUT THIS MANUAL
The following symbols are used in this guide:
This symbol indicates a CAUTION. Cautions warn against actions that can cause
damage to equipment. Please read these carefully.
This symbol indicates a WARNING. Warnings alert you to actions that can cause
personal injury or pose a physical threat. Please read these carefully.
NOTES and TIPS contain helpful information.
Fig. 1—The LWCC-M is available with 10, 50 and 100mm pathlengths.
INTRODUCTION
The Micro Liquid Waveguide Capillary Cell (WPI #LWCC-M-xxx) is a ber optic, low
volume ow cell for UV/VIS/NIR absorbance analysis; xxx represents the pathlength in
mm. The LWCC-M is available with 10mm, 50mm and 100mm pathlengths. Based on
WPI’s established liquid core waveguide technology, the analyte solution functions as
the core of a uid-lled light waveguide. Wetted parts in the sample cell light path are
PEEK, fused silica and Teon. Optical bers are used to transport light to and from the
sample cell. The cell can be used in biochemistry for DNA, RNA and protein quantication,
colorimetric nutrient and trace metal analysis, drug discovery and dissolution testing,
process control and HPLC analysis.
Similar to optical bers, light is conned within the (liquid) core of an LWCC-M by total
internal reection at the core/wall interface. 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.
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General Warnings and Cautions
NOTE: Fluid pressure uctuation, cross-contamination and the introduction of small air
bubbles can cause baseline variations and measurement inaccuracies. Use the optional
Sample Injector Kit (WPI #58006) or the LWCC Injection System (WPI #89372) to minimize
the development of small air bubbles.
NOTE: WPI’s Waveguide Cleaning Kit (WPI #501609) is recommended for cleaning the
LWCC-M between uses and sample runs.
INSTRUMENT DESCRIPTION
Parts List
After unpacking, verify that there is no visible damage to the instrument. Verify that all
items are included:
(1) LWCC-M
(1) Instruction Manual
(1) Quality Control documentation
Unpacking
Upon receipt of this instrument, make a thorough inspection of the contents and check
for possible damage. Missing cartons or obvious damage to cartons should be noted
on the delivery receipt before signing. Concealed damage should be reported at once
to the carrier and an inspection requested. Please read the section entitled “Claims and
Returns” on page 13 of this manual. Please contact WPI Customer Service if any parts
are missing at 941.371.1003 or customerservice@wpiinc.com.
Returns: Do not return any goods to WPI without obtaining prior approval (RMA
# required) and instructions from WPI’s Returns Department. Goods returned
(unauthorized) by collect freight may be refused. If a return shipment is necessary, use
the original container, if possible. If the original container is not available, use a suitable
substitute that is rigid and of adequate size. Wrap the instrument in paper or plastic
surrounded with at least 100mm (four inches) of shock absorbing material. For further
details, please read the section entitled “Claims and Returns” on page 13 of this manual.
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Hardware Description
Required But Not Provided (see Accessories)
• Fiber Optic Cables (2)
• Detection System including either a spectrophotometer or a spectrometer and
light source
Assembly
CAUTION: Unlike electrical cables, ber optic cables are fragile as they contain
glass and are subject to breakage. Avoid sharp bends in the cables and protect
them from impact or permanent damage may result.
External Fiber Optic Cable Connections
Light Input
500µm SMA
Light Output
500µm SMA
Fluid Input
800827 Connector
Fluid Output
800827 Connector
1.38”
1.00"
Fig. 2—LWCC-M-10 is shown. The LWCC-M-50 and LWCC-M-100 are longer.
The LWCC-M (10, 50, 100mm) has SMA 905 terminated (WPI #FO-500-SMA1M) ber optic
connections. The light source and detector can be connected to the LWCC-M via two SMA-
terminated ber optic cables with a core diameter of 500µm. The ber optic connections
are interchangeable in that either connector can be used to connect to the light source
or to the spectrometer. Use these ber optic connections to connect the LWCC-M to
a light source and spectrometer (detector) module of your spectrophotometer system.
Liquid Ports
As with the ber optic connectors, the liquid ports are also interchangeable. It makes
no dierence which port is the inow and which port serves as the outow. However, if
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an in-line lter is to be installed, connect it on the input side of the liquid ow path. Use
standard HPLC type 10-32 coned PEEK 1/16th tubing ttings (WPI #800827) to make
connections to the pump and waste receptacle.
OPERATING INSTRUCTIONS
CAUTION: Materials exposed to uid in the LWCC-M are PEEK, FEP and fused
silica. Any chemical that could attack these substances should not be used in the
LWCC-M. For example, hydrouoride (HF) will dissolve silica and PEEK will be
damaged by concentrated sulfuric and nitric acids (40% w/w or greater).
CAUTION: Keeping the LWCC-M clean is essential for a stable result. See
“Instrument Maintenance” on page 6.
Transmission Verication
1. Connect one 500µm diameter ber optic assembly to a light source and one 500µm
diameter ber optic assembly to the detector.
2. Use an SMA bulkhead adapter (WPI #13395) to butt-couple the bers. This is the
reference for the measurement of transmission.
3. Remove the SMA bulkhead adapter and insert the LWCC-M.
4. Record the percent transmission. Values for the 254nm and 540nm should exceed
40% and 50% respectively.
Noise Determination
Noise is determined using the ASTM E685-93 standard as reapproved in 2000. Use
methanol as the solvent at a ow rate of 1.0mL/min. Using the WPI test setup, noise
values are below 35µAU. See www.astm.org/Standards/E685.htm to obtain a copy of
the standards document.
Refractive Index
The refractive index between methanol and cyclohexane is measured using a ow rate
of 3.0mL/min. Because of the immiscibility of the solvents, ethanol is used between the
solvents to prevent unwanted interaction between methanol and clyclohexane. At the
280nm wavelength, RI values shown below are acceptable:
• LWCC-M-10 0–7
• LWCC-M-50 0–14
• LWCC-M-100 0–25
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Measuring in a Continuous Flow
This is the recommended method.
1. To help prevent clogging the ports, lter all samples using a 0.2µm vacuum ltration
disc before injection into the LWCC-M.
2. Using ber optic cables, connect the LWCC-M to a light source and a detector.
3. Clean the LWCC-M using the standard cleaning procedure described in “Instrument
Maintenance” on page 6.
4. Connect the liquid source to the LWCC-M system. A pressure of approximately
1.5–3.0 PSI is necessary to run liquid through the LWCC-M.
5. At a rate of 1mL/min., ush the LWCC-M with de-ionized water or experimental buer
solution using a pump or a syringe. Observe the light intensity or absorbance baseline
on the detector. Continue ushing until the signal is stable. See “Troubleshooting”
on page 8 if the signal does not stabilize.
Measuring Discrete Samples with WPI’s Injection System
The sample measurement
procedure can be improved
using the optional LWCC
Injection system (WPI # 89372)
as discrete, reproducible
sample volumes can be
introduced to the LWCC-M
with a seamless transition from
the baseline solution to sample
at a continuous flow rate.
The LWCC Injection System,
together with a pump and
liquid waveguide capillary cell
(LWCC-M), provides an ecient,
continual flow for injecting a
sample through the LWCC-M.
Fig. 3—The LWCC Injection System is shown with MINISTAR peristaltic pump and LWCC-M.
Pump and LWCC-M are sold separately.
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INSTRUMENT MAINTENANCE
Thorough and consistent cleaning routines are essential for maintaining the instrument
and ensuring optimal operation.
Standard Cleaning
With normal use, the LWCC-M-10 will rarely need cleaning. If measurement results
diminish, clean your LWCC-M-10. Use the cleaning kit for liquid waveguides (WPI
#501609).
1. Connect the exit tubing (for example, silicon or equivalent) from a uid port (output)
of the LWCC-M to a waste container.
2. Rinse the cell thoroughly using Ultra Pure water. Obtain a new reference intensity
and take a baseline absorbance reading.
3. Inject 1cc “Cleaning Solution 1” into the opposite LWCC-M uid port (input).
4. Inject 1cc “Methanol Solution 2” into the uid port (input) of the LWCC-M.
5. Inject 1cc “HCl Solution 3” into the uid port (input) of the LWCC-M.
6. Flush out the cleaning solutions with distilled, Ultra Pure, reverse osmosis or
equivalent quality water and take an absorbance reading.
7. Repeat these cleaning cycles until a stable absorbance signal can be obtained.
8. If the UV readings are still low after cleaning, swab the ber optic surfaces of the
sample cell with a ber optic Q-tip dipped in isopropyl alcohol.
NOTE: The sample injector kit (WPI #58006) can be used to conveniently ll all LWCC-M
models. Using the sample injector, the injection volume of the cleaning solutions per
cycle can be reduced to the internal volume of the LWCC-M (for example, 0.26mL for
a 100cm LWCC-M).
Advanced Cleaning
1. Connect the exit tubing (for example, silicon or equivalent) from a uid port (output)
of the LWCC-M to a waste container.
2. Rinse the cell thoroughly using Ultra Pure water. Obtain a new reference intensity
and take a baseline absorbance reading.
3. Fill the LWCC-M with a 10% solution of Contrad-NF (available from Decon Labs,
Inc.–www.deconlabs.com part #6002). Allow the solution to sit inside the cell for 20
minutes.
4. Flush out the Contrad-NF solution with distilled, Ultra Pure, reverse osmosis or
equivalent quality water and take an absorbance reading.
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5. Repeat steps 3–4 until a stable absorbance signal can be obtained.
NOTE: For removal of persistent contamination, the 10% Contrad-NF solution can be
heated to 60ºC prior to injection into the LWCC-M.
Storage
CAUTION: Do not leave the LWCC-M “half dried” and open to the air. Oxygen
in the air may facilitate the growth of microorganisms inside the device.
To store the instrument, clean the LWCC-M and then remove all liquid using a peristaltic
pump or syringe. Seal the uid ports using either the caps provided or an alternative.
ACCESSORIES
Table 1: Accessories
Part Number Description
FO-500AS-SMA 1M, SMA/500µm core, anti-solarization
FO-500-SMA1M 1M, SMA/500µm core, UV-enhanced
15807 Cleaning solution concentrate–100g (Solution 1)
58450 External syringe adapters
89372 LWCC Injection System
501609 Waveguide cleaning kit
500320 Silicone tubing for Peri-Star pump. 1.6mm ID x 1.6W
800490 Fiber optic foam swabs (5)
MINISTAR Miniature DC Peristaltic Pump
PERIPRO-8LS Peri-Star™ 8-channel, low rate peristaltic pump
PERIPRO-4LS Peri-Star™ 4-channel, low rate peristaltic pump
TIDAS-1 Tidas I high performance photodiode array
spectrometer module
TIDAS-BASIC Tidas E high performance ber optic based photodiode
array Spectrophotometer
D4H D4H™ deuterium/halogen light source
FO-6000 Tungsten light source
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TROUBLESHOOTING
The LWCC-M is a highly sensitive device, and it is extremely important to keep it clean.
This is especially important when working in the ultraviolet range, where unexpected
results may often be produced by contamination of the experimental solution. The high
sensitivity of the LWCC-M may create some problems that can be easily overcome with
care and forethought — the user may need to develop new skills in handling both the
equipment and the samples being examined.
Typical Contamination Eects
Issue Possible Cause Solution
Transmission in both UV and VIS ranges
becomes low or very unstable
A contamination layer (such
as biofilm) sticking to the
LWCC-M wall
Flush cell for 30 seconds each of each of
the three cleaning solvents in the waveguide cleaning kit (WPI Part #501609).
Prepare a 10% Surfactant using Contrad-
NF concentrate followed by HPLC grade
Methanol and HPLC grade 2N HCl solution.
A particle trapped in the
LWCC-M
Attach 1–5cc syringes with luer ttings to the
SAMPLE IN and SAMPLE OUT ports on the
LWCC-M. Fill one syringe with distilled water
and inject it into the LWCC-M. Use the other
syringe to push the water back through the
LWCC-M in the opposite direction. Continue
using both syringes to move the liquid
rapidly through the LWCC-M in alternating
directions.
UV transmission is
low. VIS is ne and
stable.
Optic ber and silica tubing
are coated by a layer of
metal corrosion.
Flush with 1N HCl.
Optic ber and silica tub-
ing is coated by a layer of
organics.
Flush with an organic solvent, such as
acetonitrile.
Transmission
below 250nm is
low. VIS is ne
and stable
Contamination of ber
optic cable end-faces with a
metal lm generated during
repeated connection
attempts
Wipe all ber optic end-faces, ber
connections on the LWCC-M using a ber
optic foam swab (WPI #800490) dipped in
methyl alcohol.
NOTE: Do NOT use cotton swabs (Q-Tips).
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Additional Information on Contamination
The following notes regarding contamination have been collated at WPI during the
development and testing of the LWCC-M:
• Most syringe lters contain some contaminants that absorb UV. More than likely,
this is caused by the (plastic) mold release agent used in manufacturing. The rst
few milliliters of solution coming from a new lter will have some absorption in the
UV range.
• The rst two loads of solution from most new plastic syringes often have some
contamination that absorbs UV. In addition, when plastic syringes are used to transfer
organic solvents, the rubbery gasket material in the plunger absorbs some of the
chemical. If the syringe is later used to transfer aqueous solution, the chemical will
slowly leach out. Since most organic solvents have an absorbance in the UV range,
the liquid initially released from the syringe might be found to have a dierent
spectrum than last of the liquid in the syringe, the latter having been contaminated
by the chemical in the plunger. Some commonly used organic solvents which have
“relatively low” UV absorption and are suitable for UV detection in conventional
spectrometers might not be problem-free when used in LWCC-M.
• A beaker of freshly ltered water sitting overnight in open air will probably have an
increased absorbance in the UV range because of dust from the air or growth of
microorganisms.
• Some plastic tubing will release a substance that absorbs UV. In WPI’s lab, silicone
tubing used in a peristaltic pump constantly released a contaminant even after a
week of washing.
• A bubble in the LWCC-M will result in unstable readings. Additional liquid circulating
through the device will usually push the bubble out. If the bubble doesn’t clear easily,
try introducing a larger bubble followed by liquid. This will usually pick up a small
bubble that may cling and cause problems.
• Avoid introducing particulate into the LWCC-M. If trapped in the LWCC-M, particles
can scatter light and may cause unstable spectrometer readings. The LWCC-M
contains two potential “bottlenecks” at the ber-capillary interface. Due to the diverse
applications of LWCC-M, no in-line lter can be installed which will t all users’ needs.
It is imperative, therefore, that a proper in-line lter be added to the LWCC-M if
the solution contains large particles. When the LWCC-M is directly connected a
chromatography column, a lter might not be necessary.
NOTE: If you have a problem/issue with that falls outside the definitions of this
troubleshooting section, contact the WPI Technical Support team at 941.371.1003 or
technicalsupport@wpiinc.com.
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SPECIFICATIONS
This instrument conforms to the following specications:
M-10 M-50 M-100
Optical Pathlength 10 mm 50 mm 100 mm
Internal Volume 2.4 µL 12 µL 24 µL
Wavelength Range 200 – 1000 nm
Fiber Connection (SMA) 500 µm
Transmission @ 254 nm *
> 25% > 20% >15%
Transmission @500 nm * > 40% > 35% >30%
Maximum Pressure 1000 PSI
Refractive Index @ 280 nm** < 15 mAU <20 mAU <30 mAU
Wetted Material PEEK, Fused Silica, PTFE
* Reference: Two 600 µm bers, butt-coupled
** Measured using ASTM E 685 - 93, includes intrinsic solvent absorbance
WPI U.S. Patents: 5,444,807; 5,570,447; 5,604,587; 6,603,556; 6,385,380.
Fig. 4—This graph show the percentage of light transmission at various wavelengths. The
higher the light transmission percentage, the greater the resolution.
Related Patents
Micro Chemical Analysis Employing Flow Through Detectors, 1995, U.S. Patent No.
5,444,807.
Aqueous Fluid Core Waveguide, 1996, U.S. Patent No. 5,507,447.
Long Capillary Waveguide Raman Cell, 1997, U.S. Patent No. 5,604,587.
Chemical Sensing Techniques Employing Liquid-Core Optical Fibers, U.S. Patent No.
6,016,372
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WARRANTY
WPI (World Precision Instruments, Inc.) warrants to the original purchaser that this equipment, including its
components and parts, shall be free from defects in material and workmanship for a period of one year*
from the date of receipt. WPI’s obligation under this warranty shall be limited to repair or replacement, at
WPI’s option, of the equipment or defective components or parts upon receipt thereof f.o.b. WPI, Sarasota,
Florida U.S.A. Return of a repaired instrument shall be f.o.b. Sarasota.
The above warranty is contingent upon normal usage and does not cover products which have been
modied without WPI’s approval or which have been subjected to unusual physical or electrical stress
or on which the original identication marks have been removed or altered. The above warranty will not
apply if adjustment, repair or parts replacement is required because of accident, neglect, misuse, failure
of electric power, air conditioning, humidity control, or causes other than normal and ordinary usage.
To the extent that any of its equipment is furnished by a manufacturer other than WPI, the foregoing
warranty shall be applicable only to the extent of the warranty furnished by such other manufacturer. This
warranty will not apply to appearance terms, such as knobs, handles, dials or the like.
WPI makes no warranty of any kind, express or implied or statutory, including without limitation any
warranties of merchantability and/or tness for a particular purpose. WPI shall not be liable for any
damages, whether direct, indirect, special or consequential arising from a failure of this product to operate
in the manner desired by the user. WPI shall not be liable for any damage to data or property that may
be caused directly or indirectly by use of this product.
Claims and Returns
Inspect all shipments upon receipt. Missing cartons or obvious damage to cartons should be noted on
the delivery receipt before signing. Concealed loss or damage should be reported at once to the carrier
and an inspection requested. All claims for shortage or damage must be made within ten (10) days after
receipt of shipment. Claims for lost shipments must be made within thirty (30) days of receipt of invoice
or other notication of shipment. Please save damaged or pilfered cartons until claim is settled. In some
instances, photographic documentation may be required. Some items are time-sensitive; WPI assumes
no extended warranty or any liability for use beyond the date specied on the container
Do not return any goods to us without obtaining prior approval and instructions from our Returns
Department. Goods returned (unauthorized) by collect freight may be refused. Goods accepted for
restocking will be exchanged or credited to your WPI account. Goods returned which were ordered by
customers in error are subject to a 25% restocking charge. Equipment which was built as a special order
cannot be returned.
Repairs
Contact our Customer Service Department for assistance in the repair of apparatus. Do not return goods
until instructions have been received. Returned items must be securely packed to prevent further damage
in transit. The Customer is responsible for paying shipping expenses, including adequate insurance on
all items returned for repairs. Identication of the item(s) by model number, name, as well as complete
description of the diculties experienced should be written on the repair purchase order and on a tag
attached to the item.
* Electrodes, batteries and other consumable parts are warranted for 30 days only from the date on which
the customer receives these items.
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INDEX
15807 .............................7
58006 ..........................2, 6
58450 .............................7
89372 ....................... 2, 5, 7
500320 .............................7
501609 ....................... 2, 7, 8
800490 ..........................7, 8
A
accessories .........................7
B
bubble .............................9
bubbles ............................2
C
cables .............................3
chromatography ..................2, 9
contaminants .......................9
contamination ......................8
continuous ow .....................5
Contrad-NF ......................6, 8
cotton swabs ........................8
D
D4H .............................7
dust .............................9
F
FEP .............................4
ber optic cables ....................3
lter ..........................4, 9
FO-500AS-SMA ......................7
FO-500-SMA1M .....................7
FO-6000 ............................7
H
hydrouoride .......................4
I
injection system .....................5
L
LEDspec ............................2
light source ................... 3, 5, 7
liquid ports .........................3
M
microorganisms .....................9
MINISTAR ...........................5
mold release agent ..................9
N
nitric acid ...........................4
O
organic solvents .....................9
P
particle .............................8
particulate ..........................9
parts list ............................2
PEEK .............................4
Q
Q-Tips .............................8
R
returns .............................2
S
specications ..................... 10
spectrophotometer ..............1, 3
sulfuric acid .........................4
T
TIDAS-BASIC ........................7
Tidas E .............................7
TIDAS E .............................2
troubleshoot ........................7
U
unpacking ..........................2
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USA
International Trade Center, 175 Sarasota Center Blvd., Sarasota FL 34240-9258
Tel: 941-371-1003 • Fax: 941-377-5428 • E-mail: sales@wpiinc.com
UK
1 Hunting Gate, Hitchin, Hertfordshire SG4 0TJ
Tel: 44 (0)1462 424700 • Fax: 44 (0)1462 424701 • E-mail: wpiuk@wpi-europe.com
Germany
Zossener Str. 55, 10961 Berlin
Tel: 030-6188845 • Fax: 030-6188670 • E-mail: wpide@wpi-europe.com
China & Hong Kong
WPI Shanghai Trading Co., Ltd.
Rm 25e, No8 Dongfang Rd., Pudong District, Shanghai, 200120 PR China
Tel: +86 21 6888 5517 • E-mail:chinasales@china.wpiinc.com
Brazil
Av. Conselheiro Nébias, 756 sala 2611, Santos-CEP: 11045-002, São Paulo Brazil •
Tel: (013) 406-29703 • E-mail: info@brazil.wpiinc.com
Internet
www.wpiinc.com • www.wpi-europe.com • www.wpiinc.cn
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