WO2001065401A2

WO2001065401A2 - Automation of acquisition, analysis and electronic delivery of experimental data

Info

Publication number: WO2001065401A2
Application number: PCT/US2001/006569
Authority: WO
Inventors: Gary Kruppa; Marshall Mayer Siegel; Nelson Huang
Original assignee: Bruker Daltonics, Inc.
Priority date: 2000-02-28
Filing date: 2001-02-28
Publication date: 2001-09-07
Also published as: EP1368757A2; WO2001065401A3

Abstract

A system is disclosed that is primarily meant to interface with laboratory instrumentation to acquire experimental data, process the data into a format suitable for electronic transmission, and finally transmit the experimental data to submitting persons. In the exemplary embodiment, a system is described to automatically acquire high-resolution electrospray ionization mass spectra with a commercial Fourier transform ion cyclotron resonance mass spectrometer. Upon injection of each sample, an autosampler transmits a contact closure signal to mass spectrometer to initiate data acquisition. A software package is then used off-line to accept a sample list with input information for each of the samples. Then for each of the samples, the software automatically processes and interprets the acquired data. Finally, the system prints the spectra, peak lists, exact mass reports, and e-mails the exact-mass reports to the submitting persons.

Description

AUTOMATION OF ACQUISITION, ANALYSIS AND ELECTRONIC DELIVERY OF

EXPERIMENTAL DATA

TECHNICAL FIELD

This invention relates generally to a method of automating the

acquisition, analysis, and electronic delivery of experimental

data, and more particularly, to a device which interfaces between

a measurement instrument and an electronic network to convert the

output data from the measurement instrument to a form suitable for

electronic transmission.

BACKGROUND ART

This invention relates in general to a method of automating

the acquisition, analysis, and electronic delivery of experimental

data, and more particularly, to a device which interfaces between

a measurement instrument and an electronic network to convert the

output data from the measurement instrument to a form suitable for

electronic transmission. Disclosed as an illustrative embodiment

is a Fourier transform ion cyclotron resonance mass spectrometer

(FTICR MS) system capable of delivering results in electronic form

to submitting chemists. The apparatus and method of analysis and

delivery described herein as the illustrative embodiment are

enhancements of the techniques that are referred to in the

literature relating to mass spectrometry. The analysis of ions by mass spectrometers is important, as

mass spectrometers are instruments that are used to determine the

chemical structures of molecules. In these instruments, molecules

become positively or negatively charged in an ionization source and

the masses of the resultant ions are determined in vacuum by a mass

analyzer that measures their mass/charge (m/z) ratio. Mass

analyzers come in a variety of types, including magnetic field (B) ,

combined (double-focusing) electrical (E) and magnetic field (B) ,

quadrupole (Q) , ion cyclotron resonance (ICR) , quadrupole ion

storage trap, and time-of-flight (TOF) mass analyzers. Each mass

spectrometric method has a unique set of attributes .

Generally, ion cyclotron resonance spectrometers operate by

storing ions in "traps" and manipulating the ions by using DC and

RF electric fields in a series of carefully timed events. The

underlying principle of the ICR is that ions move in a circular

path in a magnetic field. The cyclotron frequency of the ion's

circular motion is mass dependent. By measuring the cyclotron

frequency, one can determine an ion's mass.

The working equation for ICR can be easily found by equating

the centripetal force with the Lorentz force experienced by an ion

in a magnetic field:

(mv²) /r = evB Solving now for the angular frequency omega,

(omega) = (v/r) = (eB) / m

A group of ions of the same mass-to-charge ratio will have the

same cyclotron frequency, by they will be moving independently and

out-of-phase at roughly thermal energies. If an excitation pulse

is applied at the cyclotron frequency, the "resonant" ions will

absorb energy and be brought into phase with the excitation pulse.

As ions absorb energy, the size of their orbit also increases.

The packet of ions passes close to the receiver plates in the

ICR cell and induces image currents that can be amplified and

digitized. The signal induced in the receiver plates depends on

the number of ions and their distance from the receiver plates .

If several different masses are present, then one must apply

an excitation pulse that contains components at all of the

cyclotron frequencies. This is done, for example, by using a rapid

frequency sweep, an impulse excitation, or a tailored waveform.

The image currents induced in the receiver plates will contain

frequency components from all the mass-to-charge ratios. The

various frequencies and their relative abundances can be extracted

mathematically by using a Fourier transform. A Fourier transform

converts a time-domain signal (the image currents) to a frequency-

domain spectrum (the mass spectrum) . The background pressure of an FTICR should be kept very low to

minimize ion-molecule reactions and ion-neutral collisions that

damp the coherent ion motion. A variety of external ion source

designs have been developed to deal with this problem.

Most FTICR mass spectrometers uses superconducting magnets,

which provide a relatively stable calibration over a long period of

time. Although some mass accuracy can be obtained without internal

calibration, mass accuracy and resolution are inversely

proportional to m/z and the most accurate mass measurements benefit

from an internal calibrant .

While the conventional methods of FTICR spectroscopy have been

described, several examples of automated analysis and results

delivery exist in the prior art.

Galle et al U.S. Patent No. 4,844,887 discloses an automatic

analysis apparatus for performing chemical analysis on a plurality

of sample liquids. The device includes a sample delivery pump for

precisely dispensing the sample liquid into a reaction cuvette and

a reagent delivery pump for dispensing a precise amount of the

reagent into the reaction cuvette. The sample liquid and the

reagent together form a test liquid. The test liquid passes along

a plurality of photometering sections for performing a plurality of

photomeric and/or nephelometric and/or flourometric measurements. While the apparatus of Galle et al does describe an apparatus that

automatically analyzes samples, no means for the integration of an

electronic results delivery system is described.

MacPhail U.S. Patent No. 5,089,956 relates to a method for

distributing documents that have a directed relationship within an

information processing system. A user indicates to the system

which document is to be distributed to one or more recipients. The

system then builds the necessary structures to transmit the

document to the recipients. While the method of MacPhail teaches

the delivery of documents, there is no mention of integration with

any type of instrumentation. Furthermore, unlike the present

invention, the method of MacPhail cannot generate the distributed

document .

Hager et al U.S. Patent No. 5,247,661 discloses a method and

apparatus to automatically distribute an electronic document to a

preselected list of recipients. The selected document is

identified and a document profile is created consisting of the

technical or functional area disclosed within the document . The

document profile is then used to determine a preselected group of

recipients. The system of Hager et al simply distributes documents

to appropriate recipients based on embedded data. It is not

capable of interfacing with instrumentation or generating the document itself .

Kitain et al U.S. Patent No. 5,864,871 is directed to an

integrated computer-implemented corporate information delivery

system. An integral database stores research reports produced by

and received electronically from brokerage firms. Authorization

information (entitlements) specifies who is authorized to access

each research report . A delivery module allows a user to submit a

query and receive results listing research reports and corporate

information the user is entitled to that satisfy the query. The

query results may be delivered via the Internet . The system of

Kitain et al is directed largely towards the financial and

investment markets, and therefore, is not meant to be interfaced

with any type of instrumentation. Furthermore, it merely searches

a database of existing documents, it is not capable of actually

generating the document.

Toga U.S. Patent No. 5,987,504 describes a method for

delivering data. A request is placed by a user for a particular

data file, along with a storage location. A storage location may

be, for example, an e-mail address. In response to the request,

the system delivers the data to the storage location. The

advantage of the system is a queuing type process wherein the

delivery of data is postponed until network traffic lowers. Such a system does not allow interfacing with any type or

instrumentation, nor is it capable of automatically creating the

data document from collected data.

Frantz U.S. Patent No. 6,003,070 teaches a device that is

either integral or peripheral to equipment that requires monitoring

and maintenance. The device converts status signals from the

equipment into an e-mail message that is sent to the technician at

a remote location. Further, the device can then convert the e-mail

instructions from the technician into commands for the equipment.

While this device does create the sent e-mail, it creates very

simple messages indicative of the equipment status- -there is no

type of measurement or analysis involved.

SUMMARY OF THE INVENTION

Analytical instrumentation is well known to be generally very

expensive equipment. Thus, many researchers are limited in their

access to higher-level instruments, and therefore, the vital

results that could be garnered are sometimes unavailable. This,

combined with bourgeoning levels of research in many areas of

science and technology create a need for a system that makes

analytical instrumentation available to a wide variety of

researchers in a timely, effective fashion. Described herein is a system that interfaces with an analytical instrument, e.g., a mass

spectrometer, and electronically receives requests for analyses

from submitting persons, and then upon completion of analysis,

proceeds to electronically deliver the results to the submitting

person. Thus, many researchers can gain easy, effective access to

instrumentation that normally would not be available. The

illustrative embodiment discussed herein involves the use of a mass

spectrometer.

Fourier transform ion cyclotron resonance mass spectrometry

(FTICR MS) has been shown to be a powerful technique for obtaining

high-resolution exact-mass MS and MS n data over the whole mass

range of the spectrum. The resolving power in FTICR MS increases

linearly with increasing applied magnetic field with corresponding

improvements in mass accuracy and signal-to-noise ratio. These

desirable features can be routinely achieved with modern

instruments equipped with high-field superconducting magnets.

Even though very powerful data systems are used for data

acquisition and data processing, electrospray ionization (ESI)

FTICR experiments are generally conducted manually where single

samples are infused one at a time. With this manual approach, the

analysis of large numbers of samples is very time consuming,

manpower inefficient, and hence not very cost effective. At most facilities, chemists submit numerous samples of synthetic and

natural origin to the analytical mass spectrometry laboratory for

exact-mass measurements to confirm elemental formulas and thereby

chemical structures. Often, for a variety of reasons, these

materials failed to produce useful results by microanalysis . Many

of these materials are pharmaceuticals and natural products and are

very polar and thermally unstable and ESI is the ionization mode of

choice for their analysis. To analyze the large numbers of samples

efficiently under high-resolution exact-mass conditions, novel

automation methods are disclosed to automatically acquire, process,

interpret, and electronically deliver the ESI FTICR MS data.

Described herein are the hardware and software details of an

embodiment of such a system presently in routine use, using e-mail

as the delivery system, that completely integrates the automatic

acquisition, processing, and interpretation of batches of FTICR MS

data. Those knowledgeable in the art will recognize that the

delivery system could take the form of the creation of a web page,

a voice-mail message, an alpha-numeric page and compatible pager,

or the like. Furthermore, the instrumentation need not be of the

type described, but may take the form of any type of common

laboratory instrumentation. With the exemplary package described

herein, total automation is achieved for high-resolution exact-mass ESI FTICR MS data from the point of downloading sample information

from a corporate database to the electronic delivery of the exact-

mass report to the requesting chemist.

Therefore, it is an object of this invention to provide

electronic delivery of experimental results to submitting persons.

Furthermore, it is an object of this invention to provide an

apparatus to interface with an instrument to acquire experimental

results and convert these results into electronic form suitable for

transmittal .

Further, it is an object of this invention to greatly automate

the tedious process of acquiring experimental results.

These and other objects will become apparent to one skilled in

the art upon reviewing the following diagrams and description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a flow diagram of the system in an FTICR MS

configuration and e-mailing capabilities ;

FIG. 2 is an example of an acquired spectrum of a mixture of

three halogenated pharmaceuticals; and

FIG. 3 is an example of experimental results that could be e-

mailed to a submitting chemist. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

For the purposes of complete disclosure, the experimental

configuration used in the preferred embodiment will be briefly

described. Referring to FIG. 1, The FTICR mass spectrometer 101

used was equipped with a passively shielded 9.4 tesla

superconducting magnet (160 mm diameter bore) , an external

Analytica ESI source with APIlOO controller, a Hewlett-Packard

Model 1100 HPLC system (Degasser, Pump, Diode Array Detector,

Autosampler, Hand-Held Controller) , and a UNIX based Silicon

Graphics 02 Workstation data system 105. The external ESI source

was operated with a grounded capillary sprayer needle mounted

approximately 45° off-axis with nitrogen nebulizing gas at ambient

temperature and 30 lb/in² and with nitrogen drying gas heated to

130 °C and flow rate of 20 L/h. The transfer capillary voltage was

2056 V on the source side and 90 V on the analyzer side. The

skimmer voltage was 1.7 V. A hexapole ion guide in the external

ESI source was used as an external trap to accumulate ions for

times ranging from 0.5 to 5.0 s before transfer to the FTICR MS

INFINITY analyzer cell. The transfer of ions from the ESI source

hexapole ion guide to the analyzer cell is accomplished by

electrostatic ion optics. To trap the ions in the FTICR MS

analyzer cell, the Sidekick ion accumulation method and occasionally gated trapping (with and without trapping gas) were

used. Switching between Sidekick and gated trapping simply

involved changing the values of electrostatic elements in the FTICR

MS Infinity analyzer cell under computer control and varying the

timing of these voltage changes, also under computer control.

Typically 512 K data points were acquired. For low molecular

weight pharmaceutical molecules of interest, resolving powers of

50,000 (FWHM) and absolute mass accuracies of <1.0 mmu (millimass

unit) were routinely achieved. The instrument was calibrated with

Csl, poly (ethylene glycol) bis (carboxymethyl) ether (average Mn ,-

600) or a peptide mixture containing angiotensin I and II,

bradykinin, substance P, gramacidin, bombesin, actinomycin D,

leucine enkephalin, and melittin. The stability of the instrument

is remarkable in that mass accuracies <1.0 mmu can be achieved for

a number of days without retuning and recalibrating the instrument.

For this reason, external calibration was used for all measurements

but the reference standard was run at the beginning and end of the

series of samples to verify the stability and reproducibility of

the measurements . The carrier solvent used was 1 : 1

water :acetonitrile (W:ACN) with a flow rate of 50 m /min. To

illustrate the automation methodology, a mixture of halogenated

pharmaceuticals was analyzed which included chlorothiazide (C7 H6 N3 04 S2 Cl, MW 294.9488), chloramphenicol (Cll H12 N2 05 C12 , MW

322.0123), and dibromotyrosine (C9 H9 N03 Br2 , MW 336.8949). In

addition, nearly 700 proprietary samples were analyzed with the

automation instrumentation and the performance statistics for them

were evaluated.

A PC 114 was used to download sample information from a

corporate database 114 and to communicate with the Silicon

Graphics Workstation 105 through the corporate intranet. PC

programs 106 to download and transfer the sample information were

written in Visual Basic. Data processing 107 using this sample

information was performed under control of a script written in

Tcl/Tk (Tool command language/Toolkit) . Tcl/Tk is a platform

independent, extendable, and embeddable programming language that

was linked to the FTICR MS processing software ("processing

software") . This link was accomplished by extending the Tel

scripting language with built-in commands that allow access to the

processing software command interpreter, enabling all commands to

be executed from within Tel scripts.

Further versatility was added by creating built-in Tel

commands to permit access to all processing software data

parameters, as well as the raw and processed data vectors. In

essence, the processing software could be controlled completely by the Tel script . The Tel scripts can also obtain information f om

the processing software, either directly via the built-in commands

described above, or by causing the processing software to write

data (i.e., peak lists) to a file on disk which could then be

accessed by the Tel script.

Again referring to FIG. 1, the system can be divided into two

sections, one dealing with data acquisition and the other dealing

with data processing. Each section can function independently to

acquire or process a batch of data.

The autosampler, within the FTICR MS 101, upon injecting a 5

mL sample for flow injection analysis into the ESI source of the

FTICR MS sends a TTL trigger 104 to the mass spectrometer 101 to

initiate data acquisition after a preset delay time 103 necessary

for the sample to flow into the ESI source, typically about 30 s.

The pretuned and precalibrated instrument acquires and sums 30

spectra for a total acquisition time of about 30 s. This raw time-

domain data 102 is stored for future processing. After a total

time of approximately 2.0 min the next sample is injected. This

later delay of about 1.0 min is used to clean the autosampler,

tubing and source of any residual analyte, consequently cross

contamination of later samples is reduced. This process is

repeated until all the samples placed in the autosampler within FTICR MS 101 are run. A maximum of 100 samples can be run in one

batch with the Hewlett-Packard Model 1100 Autosampler.

The data reduction, analysis, and e-mailing steps described

below are automatically repeated for all the samples analyzed in a

given batch.

With regard to sample list generation, sample information is

downloaded directly from a corporate database 116 and a sample list

110 is automatically generated on a PC 114 in spreadsheet format or

a like compatible format. The sample list 110 is transferred as a

tab delimited text file or like compatible format through the

corporate intranet or other electronic network to the Silicon

Graphics Workstation 105.

The sample list 110 information (chemist name, notebook

number, request number, predicted elemental formula, autosampler

vial number, MS log book number) is used as header information for

all generated reports and the predicted elemental formula is used

for mass spectral interpretation. Each component predicted to be

present in a sample is entered individually as a separate line

entry in the sample list with the same vial number.

With respect to the raw data reduction, the raw summed time-

domain spectra 102 are automatically processed by preset operating

parameters. The processes 108 are apodization of the time-domain data, generally selected as a centered sine bell function, fast

Fourier transform with zero filling, frequency to mass conversion,

and peak picking. Options for automatic printout via printer 111

of the spectrum 112 and peak list are available.

On to data correlation and interpretation, this module 109

compares the exact masses from the list of picked peaks with those

of the possible molecular ion adducts predicted to be formed from

the expected elemental formula indicated in the sample list 110 for

the sample,. An option for automatic printout via printer 111 of

the exact-mass report is available. Also, a summary report of the

test results for all the samples is generated automatically for

bookkeeping purposes .

Lastly, there is the e-mailing of exact-mass report 113. An

alias file is set up to link submitter names with their e-mail

addresses. The Tcl/Tk macro calls up an e-mail macro which

attaches the exact-mass report as a text file and transmits it to

the submitting chemists 117 via the corporate intranet server 115.

FIG. 2 is an example of an automatically acquired spectrum of

a mixture of three halogenated pharmaceuticals in the ESI negative

ion mode. Note that the exact masses and isotopic distributions are

consistent with the predicted values for all the abundant ions.

Exemplary peaks 201, 202, 203 correspond to mass values on the mass/charge x-axis 204 and their high relative intensity on the y-

axis 205.

FIG. 3 illustrates a typical e-mailed exact-mass report using

Novell GroupWise as displayed in Microsoft Notepad for the spectrum

illustrated in Figure 2. The report lists for the given analyte

307, the name 304, charge 305, and exact-mass 306 of the predicted

molecular ion adduct, the correlated observed mass 308, the mass

error in mmu 309 and ppm 310 and the relative intensity of the ion

311. Only consistent results are e-mailed, as indicated by flag

312. Absence of the predicted exact-mass indicates inconsistent

(absolute mass error .3 mmu) or inconclusive (insufficient signal)

results. Exemplary adduct values 301, 302, 303 correspond to peak

values 201, 202, 203 on FIG. 2.

What has been disclosed is batch processing package for

automated acquisition, processing, interpretation, and e-mailing of

high-resolution exact-mass ESI data acquired by direct infusion on

a commercial high-field 9.4 tesla FTICR mass spectrometer. This

package permits reliable unattended operation of the instrument for

large numbers of samples and the efficient acquisition and analysis

of the data, thereby increasing the productivity of the system.

Typically with this system, resolving powers >50,000 (FWHM) and

mass measurement errors approximately 1.0 mmu and/or approximately 1.0 ppm are routinely achieved with ions of moderate abundance for

pharmaceuticals with molecular weights ranging from 250 to 700 Da

with external calibration. Future extensions of the software

include automated sequential acquisition, processing, and e-mailing

of MS, MSⁿ, and LC/MS data for both electrospray and atmospheric

pressure chemical ionization modes (with either internal or

external calibration) and automated instrument shut-down.

While the foregoing embodiment of the invention has been set

forth in considerable detail for the purposes of making a complete

disclosure of the invention, it will be apparent to those of skill

in the art that numerous changes may be made in such details

without departing from the spirit and the principles of the

invention.

Claims

CLAIMS : We claim:

1. A method for providing experimental results to submitting

persons comprising the steps of:

receiving a request for experimental data from a

submitting person;

executing said request; and

electronically delivering results of said request to

said submitting person.

2. A method according to claim 1, wherein said request comprises

identification data for said submitting person.

3. A method according to claim 1, wherein said request comprises

delivery destination data for said submitting person.

4. A method according to claim 1, wherein said request comprises

preferred delivery method data for said submitting person.

5. A method according to claim 4 wherein said data indicates

delivery of said results via e-mail.

6. A method according to claim 4 wherein said data indicates

delivery of said results via creation of a web page.

7. A method according to claim 4 wherein said data indicates

delivery of said results via a pager.

8. A method according to claim 4 wherein said data indicates delivery of said results via voice mail.

9. A method according to claim 1, further comprising the step

providing a user database .

10. A method according to claim 9 wherein said database comprises

entitlements for submitting persons.

11. A method according to claim 10, wherein said step of executing

comprises the steps of:

comparing said request to said entitlements; and

fulfilling said request based on said comparing.

12. A method according to claim 1 further comprising the step of

encrypting said results for security during transmission.

13. A method for automated analysis and delivery of results to

submitting persons comprising the steps of:

receiving a request for experimental data from a

submitting person;

analyzing said request to determine parameters of said

request;

interfacing with a measurement instrument to perform

analysis wherein said analysis generates said

requested experimental data;

processing said experimental data into a form suitable

for electronic transmission; and electronically transmitting said experimental data to

said submitting person.

14. A method according to claim 13, wherein said request comprises

identification data for said submitting person.

15. A method according to claim 13, wherein said request comprises

delivery destination data for said submitting person.

16. A method according to claim 13, wherein said request comprises

preferred delivery method data for said submitting person.

17. A method according to claim 16 wherein said data indicates

delivery of said results via e-mail.

18. A method according to claim 16 wherein said data indicates

delivery of said results via creation of a web page.

19. A method according to claim 16 wherein said data indicates

delivery of said results via a pager.

20. A method according to claim 16 wherein said data indicates

delivery of said results via voice mail.

21. A method according to claim 13 wherein said request is

received by e-mail

22. A method according to claim 13 wherein said request is

received by telephone .

23. A method according to claim 13 wherein said request is

received by an interactive voice response system.

2 . A method according to claim 13 wherein said request is

received by a web page.

25. A method according to claim 13, further comprising the step

providing a user database .

26 . A method according to claim 25 wherein said database comprises

entitlements for submitting persons.

27. A method according to claim 26 wherein said step of analyzing

comprises the step of comparing said parameters of said request to

said entitlements.

28. A device for use with a measurement instrument, comprising;

receive means for receiving requests for experimental

data from submitting persons ,-

interface means for interfacing with a measurement

instrument to effect analysis, wherein said

analysis generates said requested experimental

data;

acquisition means for electronically acquiring said

experimental data from said measurement instrument;

process means for processing said experimental data into

a format suitable for electronic transmittal; and

transmission means, coupled to said process means, for

receiving and electronically transmitting said processed experimental data to said submitting

persons .

29 . An apparatus according to claim 28 wherein said receive means

receives requests comprising identification data for said

submitting person.

30. An apparatus according to claim 28 wherein said receive means

receives requests comprising delivery destination data for said

submitting person.

31. An apparatus according to claim 28 wherein said receive means

receives requests comprising preferred delivery method data for

said submitting person.

32. An apparatus according to claim 31 wherein said data indicates

delivery of said results via e-mail.

33. An apparatus according to claim 31 wherein said data indicates

delivery of said results via creation of a web page.

34. An apparatus according to claim 31 wherein said data indicates

delivery of said results via a pager.

35. An apparatus according to claim 31 wherein said data indicates

delivery of said results via voice mail .

36. An apparatus according to claim 28 wherein said receive means

receives requests by e-mail.

37. An apparatus according to claim 28 wherein said receive means receives requests by telephone.

38. An apparatus according to claim 28 wherein said receive means

receives requests by an interactive voice response system.

39. An apparatus according to claim 28 wherein said receive means

receives requests by a web page.

40. An apparatus according to claim 28, further comprising

database means for storing submitting person information.

41. An apparatus according to claim 40 wherein user identification

data is stored in said database means.

42. An apparatus according to claim 40 wherein said user delivery

destination data stored in said database.

43. An apparatus according to claim 40 wherein said user delivery

method data is stored in said database.

44. An apparatus according to claim 40 wherein said database

comprises submitting user entitlement data.