Summary of Varian 356-LC
The Varian 356-LC detector is replacing the ProStar 355 detector. Order only the Varian
356-LC from now on!
The Varian 356-LC provides all of the performance of the ProStar 355, plus:
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Fully Integrated Galaxie™ Chromatography Data System (CDS) control
Extra Low-Volume cell for superior resolution
Automated operation for sequence analysis
The Varian 356-LC is the newest refractive index detector made by Polymer Labs, Varian.
Introduction
The Varian 356-LC detector is being introduced to replace the ProStar 355 detector, which will no
longer be sold. The new detector was designed and built at Polymer Labs, UK. The Varian 356LC is a high performance refractive index detector designed to meet virtually all customer needs
for refractive index detection. It has been designed to match the performance and specifications
of the ProStar 355, with the added advantage of Galaxie CDS control.
General Operation
Refractive index detectors are universal detectors designed for analysis of compounds that do not
strongly absorb UV light and, therefore, cannot be assayed with a UV detector. The usual
compounds analyzed are sugars, polymers, aliphatic amines, organic acids, and alcohols. The
Varian 356-LC is functionally identical to other deflection type refractive index detectors. A light
beam is focused towards a flow cell containing a reference and sample compartment. As the light
beam passes through both cell compartments, the light undergoes a deflection in proportion to
the difference in refractive index between the two liquids. The amount of deflection is measured
using a photodiode, which is subsequently converted to an electrical signal at the output.
Product Description and Capability
The Varian 356-LC is similar in performance to the ProStar 355, with the advantage of Galaxie
CDS control to improve capability and ease of use.
Sensitivity:
The Varian 356-LC provides three sensitivity settings, HIGH, STD & LOW, which can be selected
according to the type of analysis. For example, the LOW setting is ideal for preparative LC in
order to prevent the signal from saturating at the high concentrations typically encountered.
New User Interface:
The Varian 356-LC, like other Varian modules, has no front-panel display or hard-key control. Full
functionality is provided by Galaxie CDS software, which gives the user greater flexibility and
control than the ProStar 355.
Digital Signal Output:
The ProStar 355 was only able to offer an analog signal output, via the rear connector. The
Varian 356-LC now offers the user a digital data signal, which can be taken directly into a PC,
using an RS232 cable. This eliminates the need for an MIB800 module, to keeps cost down.
Automatic Control via Galaxie CDS
The Varian 356-LC control is fully integrated into Galaxie CDS software, allowing the user to
remotely control the detector for overnight operation. The user can also purge and A/Z the
detector remotely, allow complete automation of the system.
Product features and benefits
Feature
Benefit
Low dead-volume flow-cell
Improved resolution and sensitivity
Active temperature compensation
Lower base-line drift and improved reproducibility
Galaxie CDS Control
Improved productivity through automated, unattended
sequence runs
Easy to use and consistent user interface
Digital data output
Simple to set up
Better value – do not need an expensive analog to digital
interface board
Improved traceability using Galaxie CDS operation logs
Reduced maintenance and quick start-up as the LED is
always on and has a indefinite life time
Long-Life LED
Ordering Information
Varian 356-LC detector:
PL0880-0000. The Varian 356-LC is voltage independent and one part number suffices for all
voltages.
Varian 356-LC light source assembly:
PL0880-0110. Contact Technical Support. The Light Source is a low voltage LED, which is
designed to last for many years.
Varian 356-LC purge valve assembly:
PL0880-0210. Contact Technical Support. The most common supply needed for the Varian
356-LC is a replacement purge valve.
Varian 356-LC flow cell assembly:
Flow Cell PL0880-0120
Bottom Seals PL0880-0160
Top Seals PL0880-0150
The flow cell seals can deteriorate overtime, especially if exposed to incompatible solvents.
Therefore these parts are a common supply. In addition, if too much backpressure is put on the
flow cell by accident, it can leak. This requires a replacement flow cell. The flow cell is not simple
to replace and should by be performed by a qualified Varian service engineer.
Product Positioning
The Varian 356-LC can be positioned in two different ways:
It is a high performance general use refractive index detector.
The high performance position arises from the low noise, low sensitivity to temperature changes,
advanced capabilities such as automatic flush of the detector cell and automated optical auto
zero.
It is an ideal detector for automated analysis, especially for reverse of normal phase
applications.
The automation position arises from the ability to automatically flush the reference cell, to
automatically zero the detector and equilibrate the detector using Galaxie CDS. This is most
emphasized when using either reverse or normal phase chromatography because the customer
may want to change the mobile phase conditions for different analyses automatically while
keeping the same column. Even if the solvents are premixed and positioned in the A and B
reservoir, there will still be a change in the refractive index when the new solvent is used. The
optical auto zero and the reference cell flush will reset the detector so that it is at its most
sensitive with the new solvents.
Comparison with the PL-ELS 2100
The PL-ELS 2100 evaporative light scattering detector is also regarded as a universal detector
and is often seen to compete or even replace the RI in certain application areas, such as sugars.
The positioning of the ELSD against the LC-356 must be clear, as Varian sell both products.
Both ELS and RI detection have their strengths and weaknesses (see comparison table below).
However, ELSDs are typically more expensive than RID, and there is no justification for the
higher cost and added complexity of method development if the RI detector can already
adequately perform the analysis.
Competition
Detector type
Varian 356-LC
Differential
refractometer
1 - 1.75
HP 1100
Differential
refractometer
1 - 1.75
Refractive index
range
Noise(RIU)
<5 x 10-9
+/- 2.5 x 10-9
-7
Drift (RIU/h)
<2.5 x 10
2.0 x 10-7
Temperature control OFF, 30-50 °C
Ambient +5 to 55 °C
(1 °C increments)
Flow cell
6 µL
8 µL
Electronic autozero Yes
Yes
Optical autozero
Yes, Automated Yes, automated
Auto purge
Yes, Automated Yes, automated
Polarity reversal
Yes
Yes
User interface style Galaxie CDS
Gameboy
Waters 2414
Differential
refractometer
1 - 1.75
Shimadzu RID 10A
Differential
refractometer
1 - 1.75
1.5 x 10-9
2.5 x 10-9
-7
+-1.0 x 10
1x10-7
OFF, 30-55 °C
OFF, 30-60° C
(1 °C increments) (1° C increments)
10 µL
9 µL
Yes
Yes
Yes
Yes
Yes, automated ?
Yes
Yes
Keys, LCD
Keys, LCD
Varian 356-LC specifications
Detector type
Deflection
RI range (RIU)
1.0 ~ 1.75
Range (RIU)
150 – 600 x 10-6 /FS
Linearity (µRIU)
600
Sensitivity (mv/µRIU)
LOW (2), STD (4), HIGH (8)
Short-term noise (nRIU)
< 5.0
Drift (nRIU)
< 250
Response time (s)
0.1 - 5.0
Temperature control
OFF, 30–50 °C (1 °C increments)
Cell volume
6 µL
Light source
LED 880 nm
Analogue output
1 V FSD
Digital output
24 bit (10 Hz) via serial port
Polarity
Positive / Negative
External communication
RS232
Autozero
Yes
Purge
Yes
Flow rate range
0.1 - 10 mL/min
Pressure rating
100 kPa (15 psi)
Internal volume- inlet
15 µL
Internal volume- outlet
459 µL
Total internal volume
Normal operation 474 µL
Purge mode 491 µL
Wetted material
316 SST, quartz glass, PTFE, perfluoroelastomer
Power requirements
AC 100~240 V 50/60 Hz
Power consumption
150 W (max)
Dimensions (wxdxh)
(unpacked)
296 x 475 x 212 mm
Dimensions (packed)
460 x 775 x 385 mm
Weight (unpacked)
11 kg
Weight (packed)
13.5 kg
PC control (software)
Galaxie Chromatography Data System
Remote operation
Remote purge and autozero
Safety features
Error and leak detection