EVOLUTION OF VACUUM PUMP REQUIREMENTS FOR LIQUID...

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


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


PRIMARY PUMPS

A primary vacuum pump is a pump that exhausts to atmospheric pressure


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)


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


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


8

WHAT IS A LIQUID CHROMATOGRAPHY MASS SPECTROMETER?

9


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


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


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


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


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


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


Drag stage turbomolecular

pumps

Combined inlet and

backing primary pump

240 ls-1 240 ls-1


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



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


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”


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


22


LCMS TMP CONFIGURATIONS24


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


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


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)


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


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


30


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


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

Date post:	05-Feb-2020
Category:	Documents
Upload:	others
View:	3 times
Download:	0 times

EVOLUTION OF VACUUM PUMP REQUIREMENTS FOR LIQUID...

Documents