EVOLUTION OF VACUUM PUMP
REQUIREMENTS FOR LIQUID
CHROMATOGRAPHY MASS
SPECTROMETRY
Andrew Chew and Ian Olsen
Edwards Global Technology Centre, UK
Wednesday 12th October, 2016
This talk is based on that made at IVC-20 in Korea, August 2016
DISCLAIMER
Edwards Ltd, disclaim any and all liability and any warranty whatsoever relating to the accuracy,
practice, safety and results of the information, procedures or their applications described herein.
Edwards Ltd does not accept any liability for any loss or damage arising as a result of any
reliance placed on the information contained in this presentation or the information provided
being incorrect or incomplete in any respect. Note that the information contained herein is only
advisory and, while Edwards can provide guidance with respect to the potential hazards of using
hazardous gases/materials, it is the end-user’s responsibility to conduct a risk
assessment/hazard analysis specific to their operations and environment and to comply with
government regulations
2
Evolution of vacuum requirements for liquid chromatography mass spectrometry A.D. Chew and I. Olsen
CONFIDENTIALITY STATEMENT
This presentation has been prepared exclusively for the benefit and use of Edwards and is
confidential in all respects. This presentation does not carry any right of publication or disclosure,
in whole or in part, to any other party. This presentation is the property of Edwards. Neither this
presentation nor any of its contents may be used for any purpose without the prior written
consent of Edwards. This presentation includes certain statements, estimates, targets and
projections as to anticipated future business performance. Such statements may reflect
significant assumptions and subjective judgements by Edwards which may or may not prove to
be correct. Edwards makes no representations as to the accuracy, completeness or fairness of
this presentation and so far as is permitted by law, no responsibility or liability whatsoever is
accepted by Edwards for the accuracy or sufficiency thereof or for any errors, omissions, or
misstatements relating thereto. The contents of this presentation is confidential and should not be
distributed.
3
Evolution of vacuum requirements for liquid chromatography mass spectrometry A.D. Chew and I. Olsen
ABSTRACT
In addition to partial pressure analysis and leak detection, ‘Mass Spectrometry’ incorporates a
large vacuum market and application sector including Pharmaceutical, Medical and Life
Sciences.
In this paper we will focus on the historical evolution of primary and secondary vacuum pump
requirements in Liquid Chromatography Mass Spectrometry (LCMS).
This will be discussed in relation to pump types and capacity divergence, capital cost, cost of
ownership, environmental impact, safety and communications protocols. Future trends and
market developments will also be discussed
4
Evolution of vacuum requirements for liquid chromatography mass spectrometry A.D. Chew and I. Olsen
PRIMARY PUMPS
A primary vacuum pump is a pump that exhausts to atmospheric pressure
Evolution of vacuum requirements for liquid chromatography mass spectrometry A.D. Chew and I. Olsen
5
Capacities
~1 to 2,000 m3/h
(mbar)
10-3 1 103
Atmosphere
Liquid Ring
Diaphragm
Oil Sealed Rotary Vane & Piston
Screw
Roots / Claw
Scroll
Typically operating in
the continuum flow
regime: Speed versus
Displacement
SECONDARY PUMPS
A secondary vacuum pump is a pump that continuously exhausts to a primary pump or requires a
primary pump to create a level of vacuum it can operate from. It is often referred to as a high
vacuum pump
10-9 10-6 10-3 1
TurbomolecularCryogenicIonizationDiffusion
Maximum
Exhaust
Pressure
Diffusion
Ion
Cryogenic
Turbomolecular
103
atmosphere
Other pumps
include: Drag, NEG
and TSP pumps
(mbar)
Evolution of vacuum requirements for liquid chromatography mass spectrometry A.D. Chew and I. Olsen
6
Capacities
~1 to 40,000 l/s
Typically operating in
the molecular flow
regime
Pump Type
Entrapment Gas Transfer
Kinetic Positive Displacement
VACUUM PUMP CLASSIFICATION
Evolution of vacuum requirements for liquid chromatography mass spectrometry A.D. Chew and I. Olsen
Gases retained in pump
Cryogenic & Ion
Diffusion & TurbomolecularScroll, Claw, Screw,
Piston, Oil Sealed,
Liquid Ring, Roots etc
Gases moved and compressed
7
WHAT IS A LIQUID CHROMATOGRAPHY MASS SPECTROMETER?
Analytical chemistry technique that combines physical separation capabilities of liquid
chromatography (or HPLC) with the mass analysis capabilities of mass spectrometry (MS).
Essentially, a mass spectrometer identifies chemical compounds
Typical mass range from 100 to 50,000 amu cf RGAs 1 to 200
Used by forensic, environmental or clinical scientists, biochemists, homeland security specialists
or food safety agencies
e.g. medical application can span medical/clinical diagnosis, drug discovery, clinical trials and
purity testing of the final product during their synthesis and manufacture
Evolution of vacuum requirements for liquid chromatography mass spectrometry A.D. Chew and I. Olsen
8
WHAT IS A LIQUID CHROMATOGRAPHY MASS SPECTROMETER?
9
Evolution of vacuum requirements for liquid chromatography mass spectrometry A.D. Chew and I. Olsen
Sample prepared and introduced
Ionisation by different techniques eg ESI or APCI
Analysers separate ions which have different mass-to-charge ratio.
They are accelerated, focused or brought to resonance by electrical and/or magnetic fields
Selected ions are directed into the detection chamber for quantification
Results are output to a PC for data analysis
Mass
Sorting
Data
Analysis
Inlet
Ionization
Analyser
Ion
Detection
Detection
Source
+
Sample
Introduction
EXAMPLE LCMS - QUADRUPOLE
Evolution of vacuum requirements for liquid chromatography mass spectrometry A.D. Chew and I. Olsen
1 to 3 mbar
Chamber 2Chamber 1Air
1013 mbar
@ 200C
Chamber 3
Backing Port
f0
.2-0
.4 x
0.1
mm
f 0
.6-0
.9 x
0.1
mm
f 3
.0-5
.0 x
1.0
mm
1000 sccm
1.0 x 10-3
mbar
1.0 x 10-6
mbar
Split flow
Turbo
Primary/Backing Pump OR
Higher Vacuum (Lower pressure)
10
The function of a primary pump is to operate as
a backing pump for the turbo-molecular
pumps(s) and to remove carrier gas and/or
solvent carry over
High vacuum conditions prevent collisions of ions
with residual molecules in the analyser during the
flight from the ion source to the detector: they
increase the efficiency of ion transfer and
detection
What types of LCMS are there?
Single quadrupole 1,500 - 3,000 amu Simple
Ion trap 1,500 - 3,000 amu
Triple quadrupole 1,500 - 3,000 amu
Time of Flight 15,000 -20,000 amu
Quadrupole Time of Flight 16,000 – 30,000 amu
FT Ion Cyclotron Resonance 40,000 - 50,0000 amu Sophisticated
PRIMARY PUMP PROGRESSION11
Evolution of vacuum requirements for liquid chromatography mass spectrometry A.D. Chew and I. Olsen
Sogevac SV40Bi
Sogevac SV65Bi
Sogevac SV120Bi2 x Sogevac SV65Bi
XDS46i & XDS100B
Ebara EV-SA20
Agilent MS40+
1990s 20102005 20152000
XDS35i
Busch R5 Range
nXL110i & nXL200i
25 slm
LCMS VACUUM HISTORY: 1990S – 2000S – 2016 - FUTURE
Primary pumps
Typically operating in the 1 to 8 mbar
range
Gradually increasing in size for
improved ‘sensitivity’
More recently smaller in size for entry
level LCMS
‘Wet’ to ‘Dry’ - no oil to dispose of and
typically lower power/heat
Evolution of vacuum requirements for liquid chromatography mass spectrometry A.D. Chew and I. Olsen
12
LCMS VACUUM HISTORY: 1990S – 2000S – 2016 - FUTURE
Secondary pumps: TMPs
Turbomolecular replaced (1990s) oil
diffusion pumps - no ‘accidents’ and
lower CoO (power)
Initially pure turbo stages and then
additional drag stage (of various types)
added.
“Splitflow” pumps introduced in early
2000s reducing pump count
Edwards adds third viscous
“regenerative” stage
Evolution of vacuum requirements for liquid chromatography mass spectrometry A.D. Chew and I. Olsen
13
Fully bladed
turbomolecular pump –
exhaust pressure < 0.1
mbar
LCMS HISTORICAL PROGRESSION #1
CH1
2.0
mbar
CH2
4.0 E-2
mbar
CH3
1.5 E-6
mbar
30 m3h-1
780
sccm
8 m3h-1
200 ls-1 200 ls-1
Evolution of vacuum requirements for liquid chromatography mass spectrometry A.D. Chew and I. Olsen
14
CH1
2.0
mbar
CH2
3.0 E-2
mbar
CH3
1.0 E-6
mbar
30 m3h-1
780
sccm
Twin discrete nEXT240D
LCMS HISTORICAL PROGRESSION #2
Drag stage turbomolecular
pumps
Combined inlet and
backing primary pump
240 ls-1 240 ls-1
Evolution of vacuum requirements for liquid chromatography mass spectrometry A.D. Chew and I. Olsen
16
CH1
2.0
mbar
CH2
4.0 E-3
mbar
CH3
1.5 E-6
mbar
30 m3h-1
200 & 200ls-1
780
sccm
nEXT Splitflow
One splitflow
turbomolecular pump
LCMS HISTORICAL PROGRESSION #3
Evolution of vacuum requirements for liquid chromatography mass spectrometry A.D. Chew and I. Olsen
17
Three stage splitflow
turbomolecular pump
Smaller size primary pump
CH1
2.0
mbar
CH2
4.0 E-3
mbar
CH3
1.0 E-6
mbar
15 m3h-1
780
sccm
200 & 200ls-1
+ 30 m3h-1
nEXT Splitflow + BOOST + aperture <
LCMS HISTORICAL PROGRESSION #4A
Evolution of vacuum requirements for liquid chromatography mass spectrometry A.D. Chew and I. Olsen
18
Three stage splitflow
turbomolecular pump
Same size primary pump
CH1
2.0
mbar
CH2
4.0 E-3
mbar
CH3
1.0 E-6
mbar
1560
sccm
200 & 200ls-1
+ 30 m3h-1
LCMS HISTORICAL PROGRESSION #4B
30 m3h-1
Increased inlet flow
for improved
“sensitivity”
Evolution of vacuum requirements for liquid chromatography mass spectrometry A.D. Chew and I. Olsen
19
30 m3h-1
LCMS HISTORICAL PROGRESSION – FURTHER USE OF “BOOST”
Combined “Boost” from
turbos 1 & 2 for high
capacity viscous pumping
CH1
5.0
mbar
CH2
3.0 E-2
mbar
CH3
1.0 E-5
mbar
5000
sccm
240 ls-1 240 ls-1
CH3
1.0 E-7
mbar
240 ls-1
Now triple quad mass spectrometer
“Boost” from turbo 3
reduces backing pressure
for turbos 1 & 2
Evolution of vacuum requirements for liquid chromatography mass spectrometry A.D. Chew and I. Olsen
22
Evolution of vacuum requirements for liquid chromatography mass spectrometry A.D. Chew and I. Olsen
LCMS TMP CONFIGURATIONS24
Evolution of vacuum requirements for liquid chromatography mass spectrometry A.D. Chew and I. Olsen
GENERAL CONSIDERATIONS - PRIMARY
Oil in OSRV has to be disposed of - risk of accidents and or contamination, leaks (seal deterioration), spillages and suck-back
Noise, both mechanical (vibration) and audible. Pumps are not necessarily the noisiest component in the lab
OSRV often require the use of acoustic enclosures to reduce from 57 to 52dB(A): whereas scroll is 52dB(A) with better audible ‘finger-print’
Power. Scroll pumps typically 50-60% lower power than equivalent OSRV (lower on reduced speed/stand-by mode). Usually inverter driven for consistent performance worldwide
25
Evolution of vacuum requirements for liquid chromatography mass spectrometry A.D. Chew and I. Olsen
GENERAL CONSIDERATIONS – TURBOPUMPS
Optimisation of turbopumps means significantly fewer pumps (power) needed
Increased gas flows and/or better vacuum levels now possible
Footprint – newly introduced pumps should be backwardly compatible with previous versions but bring
performance benefits
Serviceability – many users perform their own maintenance and service pumps
Cost-of ownership
Uptime – no risk of oil accident (compared to diffusion pumps)
Control and communications: parallel, serial or manual
26
Evolution of vacuum requirements for liquid chromatography mass spectrometry A.D. Chew and I. Olsen
SERVICE REQUIREMENTS
Drivers are: cost, up-time, end-user serviceability
OSRV: Oil change (2 to 6 months)…can take 24 hours to recover performance
nXDS scroll pumps: up to 5 year bearing service interval….(check performance after 2.5 years: tip
seal may not need replacing if ok for Application)
nEXT TMP
- oil reservoir lubrication service every 2 years end-user 10 mins
27
Fine Leak
Valve (FLV)
Dry-Pump
Under Test
Cap Man
Gauge
Pirani
Gauge
Turbomolecular
PumpRotary Vane
Pump
Quadropole Mass
Spectromter
Hot Ionisation
Gauge
Analysis
Chamber
Exhaust
Exhaust
CLEANLINESS EVALUATIONP R DAVIS, R A ABREU AND A D CHEW, ‘DRY VACUUM PUMPS – A METHOD FOR THE EVALUATION OF THE DEGREE OF DRY’
(INVITED) JOURNAL OF VACUUM SCIENCE AND TECHNOLOGY A, 18, (2000)
Evolution of vacuum requirements for liquid chromatography mass spectrometry A.D. Chew and I. Olsen
28
INLET MASS SPECTRA - OSRV PUMP
0 20 40 60 80 100 120 140
1E-8
1E-7
1E-6
File :bhal1046
Date :08.07.98
79
81
91
41 55
67
69
18 (H2O)
Pion = 1.6 x 10-8 mbar
Pline = <1.0 x 10-4 mbar
Time = >24 hours
2 (H2)
28 (N2/CO)
Pa
rtia
l P
res
su
re (
mb
ar)
Mo lecu lar Weight (m/e)
M/e =14 = CH2 separation of groups
Evolution of vacuum requirements for liquid chromatography mass spectrometry A.D. Chew and I. Olsen
29
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140
1E-10
1E-9
1E-8
1E-7
Pump A
32 (O2)
69 (CF3)
14 (N)
2 (H2)
Pa
rtia
l Pre
ssu
re (
To
rr)
Molecular Weight (M/e)
INLET MASS SPECTRA CONVENTIONAL AND XDS SCROLLS
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140
1E-10
1E-9
1E-8
1E-7
Pump D
100 (C2F
4)
119 (C2F
5)
97 (C2F
3O)
32 (O2)
69 (CF3)
14 (N)
2 (H2)
Pa
rtia
l P
ressu
re (
To
rr)
Molecular Weight (M/e)
Conventional scroll - PFPE
peaks m/e = 69 and 119 from
exposed bearings
XDS - no bearings in vacuum
space
Evolution of vacuum requirements for liquid chromatography mass spectrometry A.D. Chew and I. Olsen
30
Evolution of vacuum requirements for liquid chromatography mass spectrometry A.D. Chew and I. Olsen
KEY INGREDIENT FOR DESIGNING THE BEST SOLUTION31
TransCalc HSM
Used to predict vacuum system solutions with different flow rates, pressures, gas species
and temperatures (like mass spectrometers). Used by Edwards engineers in collaboration
Minimise number of hardware iterations and speed up instrument development time
Evolution of vacuum requirements for liquid chromatography mass spectrometry A.D. Chew and I. Olsen
SUMMARY
Applications in the Instrumentation Sector have discrete and also common requirements for
Vacuum
‘Wet’ to ‘Dry’ primary and secondary
Reduced # of pumps: single to split-flow TMPs and scroll pumps with multi function
Environmental: power, cleanliness, no oil disposal….
Pumps – constant performance
In-situ service
Universal operation (inverters)
Sophisticated Modelling – predictive performance, reduced number of iterations
32
MERCI
EVOLUTION OF VACUUM PUMP
REQUIREMENTS FOR LIQUID
CHROMATOGRAPHY MASS
SPECTROMETRY
Andrew Chew and Ian Olsen
Edwards Global Technology Centre, UK
Wednesday 12th October, 2016
This talk is based on that made at IVC-20 in Korea, August 2016
Top Related