Computer Programs for the Evaluation of Low Resolution Mass Spectrometry Data

V. Zitko

Biological Station, St. Andrews, N.B., EOG 2XO

August 1981

Canadian Technical Report of Fisheries and Aquatic Sciences No. 1025

GcMiinmenl d C8nada Gowememenl du Canada FISherieS and Oceans Pflct-es et Oceans

Canadian Technical Report

Fisheries and Aquatic Sciences

August 198

COHPUTER PROGRAMS FOR THE OF

V. Zitko

Fisheries and Environmental Sciences

Department Fisheries and Oceans

Biological Station

St. Andrews, New Brunswick

This is the one hundred and thirty-ninth

the Biological Station, St. Andrews, N.B.

ister

Cat.

programs for 5, iii +

• Fs

evaluation resolution mass spec ~ Tee ,.

-2-

OOOl,GClOOO n?RCG?.At·i ~1SPPTCu

5 "E'!TEP 20-44 DATA, c1AX. FOLLO!JED BY EACl\QR. 7 " 0 FILES -- GOTO l 0" 8 STOP

:1ASS PA'lGE"

23, 1 36. 133, 0

THE'! 50

F C< D THE'l 580 LET D=C

EXT PR!:lT D

600 FOR K=KI TO K2 6 LET V=I\ITCIOO•M<Kl/Dl 620 IF V<l THEN 640 630 °"<1\IT iGV,

NEXT !{ PRl'lT

660 PRI'JT "MIN °EAKS, OR1ALP:ED •100" 670 LET S=Sl=O 680 FOR K=KI TO i\2 690 IF :1<Kl<O THE~J 730 700 IF tHKl>SO THE\! 730

I LET S=S+MCKl 720 LET Sl=S +M(Kl 2 130 'JEXT K

LET N=1<2- + l 750 LET S= S I'J 760 LET SI=C(Sl-'l* S•2ll/CN-lll•.S 110 PR "BASELINE=";$ 780 P"<INT "DEIJLATIO\I=";S! 790 FOR K=l<! TO K2 800 IF <l0<3•Sl :HE'J 830 80 LET V=I'JTC OO•M<Kl/Dl 805 IF IJ>=l THEN 830 8 0 LET V=INTCIOOOO•MCKl/Dl 820 830 840 °RINT 850 RETURN

695 NEXT J

( ;

3 );u __ -------

G TO 0 GC • • J 0"

SB>PER PGCH

000 M=ZEP 1010 :1AT G=ZER 020 DREAD # l, X,

1030 DREAD #I,Y,G I 040 MAT ~1=M- G !050 GOSUB 2000 1060 RETURN 2000 PRINT "S>l=";Ac I,J), "SB=";AC I,J+l) 20!0 LET C=D=O 2020 FOR K=70 450 2030 LET C=:H lO 2040 IF C<D THEN 2070 2050 LET D=C 2070 NEXT K 2080 PR T D 2090 FOR K=70 TO 450 2100 LET V=INTCIOO•HCK /D) 2 0 IF V<5 THE'~ 2!30 2120 °:FUNT lU 2!30 NEXT K 2140 PRI~H 2150 RETUR~I

*

STRt'CTED "S'lTEP 20-BODATA RGCL:1,S'1,S>l.-··C1AX 9J, ,E•!D BYO"

S 0 ACE IS <40, 0 " LE5 ...... GOTO ou

85 275

390

"ENTEP THE \JI - > Q, + )"

;"PGCLYi ;A(E;l) ;~·- - ------- ---

THE~·J THE;J 700

; 82.~ J

~1= ZEF G= ZEP P=ZEP Y=S-2 ':0 5+2

DREAD #!, v, FOR I= Z TO Z IF Cll>G(I) THE~ GCTO I 00 LET GCU=MCU LET PC I )=v

!00 NEXT I Ill 0 NEXT Y

20 MAT ~-l= ZEF

1280 290

!300 13!0 320 330 340

!350

FOR I=Z TO Z! IF 1#<>- I THE'J 50 IF 0 (1)=5-! THE'·! 1160 IF PCIJ=S THEN I f

l IF PCI <>S+I THE'J I 70 LET

P!HNT "SCAcl ; S LET C=D=O FOR K=Z TO 2:1 LET C=~1 < l IF C<D THEN !270 LET D=C NEXT PRIN D

FOR l<=Z TO Zl LET V= INT <I 00*~1 C !< IF 11<5 THE~l 1330 0 R I~lT !{; 1J,

EXT K "RINT RETUR•l

/Dl

50 I= 52 FOR J= l

READ D(l,J) :JEXT J

"f LE" F~

30-49 DATA THE G FO"':lATIOi :RGC1AS:C,," '5),5 c1AX.&BAC!{G 0 • (+0'5)"

263,260.269.265, ,o,o ,2 220.~2 7 .. 0..~ o .. o,

o. ; 27 '269, 276,275, o, o, o, 0

280,276,0, o, o,o,o,o

'!33,29!.239.35!,349,0.0.0.0 227.300,293,3!0,3 7,3 5,312.0,0

''XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX'' 30/,"FILE",F$

7 ··xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx·· TO 0

! )

300

; ">1AXn ;D( IJI ; ,.BACKGR .. ";:c< I., J+ 1) I "II #iliiflllfillilillf# illii.w#lill#lllil~ll#f!ll#"

29 250 L"''T X=D I, lC 260 LET =DCI,K+I

*

270 G CSUB 500 275 on T TAB( 280 \j EXT ){ 285 PPI~T TAD 30)J •••••• ·~·~· ••••• ~ •••••• 290 'SEX'~" J 295 ?R T TAB JQ);H++++++++++++++++++++ ++ 300 NEXT I 3!0 E>lD 500 LET A=B=O 5 0 FOR N=X T 520 LET A=:1 530 IF A<B THE'J 540 LET i3=A 550 LET 2>'l 560 'JEXT 570 "'R T "BASE 0 EA!\ IS";;>: 580 FOP 'l=X TOX! 590 600 6

LET LET LET LET

~·f=

0= 630 LET Q=IN'TC

650 660

'PR PR FO"'

T L= l TO

670 PR T "-"; 1\IEXT

690 IF Q<= THE'! 7 700 "'RI'JT TABC0+6),v; 710 NEXT 'l 7!5 PRINT 720 PETUR11J

*

I 600

!{

V£5 );

THE OCCLT~RENCE s 2

20"

(2)*'

F I0'l S" SCA'JS"

1-

530 NSXT J 540 P'S'I'JT ~~-------------------------------------------------550 °?l'lT"ACJC'THEF 55 Pl!'" Q2 552 F Q2= 553 IF Q2=2 554 !F 02=3 560 E:~D

LET 610 F I= 620 LET 7_ = Z 630 LET 640 650 660 670 675

6

LET

!...ET

LE.: T =

680 LET P:"\j

1 IF : <= 682 690 69 5 LET R= I"""' C 700 T>ETURcl 7 LET R=999 720 GOTO 700 000 PFI'JT "IO'l

!005 I~1PUT J 10 0 IF J=O THE'! 55 !020 LET A=B=O 1030 FOR l=l TO 1040 IF (!,J)=O 050 LET A= A( '" 1060 IF A<b THE'!

!070 LET B=A 1080 LET 'C= 1 ! 00 EXT I

120 PRINT HI C'S H; !30 PRii'.JT "ttl! lUi

35 LET !\2= !140 FOR 1150 LET

60 LET l I 70 LET Yl= !80 LET Q= 60*0

!190 LET ~= T Q

12!0 D~Ii"T !(2+1-220 FOR L=4 TO

1230 PPIJT u_ u;

240 'JEXT L !245 OR T 1250 \fEXT !3!0 GCTC I

*

500

11####"

correc­the array

gas chromatogram

more than three scans tends to minimize the

area deter-In a

procedure, IS is then the recon-

after the end ) .

of area determination.

fication of the quanti­round-corrected mass

ines 2000-2040), normalized printed (lines 2120-21 ) , if

least 300

2-

This program, developed by Kavanagh derives all empirical formulae for a given calculates isotope abundanc ies, and compares these to the observed values. Listing of the program, obtained from the author, was translated into Tektronix Plot 50 BASIC. The formula computing algorithm was slightly modified and the isotope abundancies algorithm has not been changed. Program output has been directed to magnetic tape and several minor modifications have been implemented. A detailed documentation of the new version is given below.

N$ line is the name le tape for recording the The file is found and the title is recorded lines 16-20).

The

-iodine, 2-bromine, 5-phosphorus, 6-silicon, ?-fluorine,

, and 10-carbon). Input of I) means that the I-th eiement

considered, respectively. Carbon and

factorials from 0 to weights of the lightest stable isotopes elements potentially under consideration, and

"apparent" atomic weights used in the formula algorithm. 0(10) contains numbers of atoms of individual elements in a given formula. 18) contains calculated isotope abundanc ies, 8 final isotope abundanc ies, and FO 8) is an array of normalized intensities. C(l0,3) describes given isotopic formula, rows represent elements, columns represent isotopes. S(l0,3) contains natural stable isotope ahundancies of the 10 elements. 'lasses of ions investigated are stored in W( 10). The array

) contains "procedural instructions" stored as follows: positions 1-10 contain either "0" or "!" for analysis (calculations of formulae, isotopic abundancies, and comparison with observed abun­dancies) or formulae calculation only, respectively; positions ll-20 contain "0" or "!" for molecular or even electron ion, respectively; positions -30 contain numbers of ions; positions 31-40 abundancies of "A-1" ions; and positions 41-50 the fit." Y store observed isotope ahundanc ies (rows) and up to 5 masses. G(l of formulae found.

The arrays are initialized lines -76 and elements are chosen lines 15-2 The choice is recorded on tape (line 2.12). Arrays T, 2, and S are filled in lines 230-275.

A parameter input loop K (lines is used to enter nominal masses of up 10 ions, pro-cedural instructions (molecular or even electron ion, comparison of observed and calculated iso pe abundancies or calculation of formula only, number of nominal mass , abundancies of A-1 , and

fit" , and observed

2

4 8

7" AS 20-

9 5TCP FILES L5VA

LET 52=250 5=5 i 52

50 F G 5l>=G<I5+1 THEN 520 GC 5l>=G 15+2> THEN 700 530 LET PO= 5

6 0 620 630 632 640 650 700 7 0 750 820 830 840 350

870 880

LET Jl=O 2=15+ T 5 + 0

2 < (12+ 580 =12

>G( 2+2l THEN 590

LET P3=I2 GOTC 632 '!EXT I 2

p THS>~ 630

IF P3-P0<=3 THEN 700 GOSt!E 820 LET 5= I 5+P3- PO- !

EXT 5 GCTO END LST B =CGCP3 -GC 0 0 )/ P3-"'C LET B2=<G<PO +GCP3l *(DJ- 0 0- l/2 LET E3=0 FOR = 0 0+ TO P3-LET B3=!33+G 'JEXT LET E4=E3-E2

F !34<. *E2 THE:"l 190 F !34< "'HE'l 2 90

0"

5 886 887 888 889 890

:OF: T u:-1AXu "(u;GCP ; )";"BACl(u;pQ;"cu;G('PQ);")u; PR I~T ''END''; !13; wt; G ( P3); '') t•

PRINT u ____________ u

0 R "APEA=";B4,"BACKGP.=";B2,"BACKGP.SL0°S=";B! 2000 MAT M=ZEB

t1AT L=ZEF 20 5 LET X=P 20 I 6LET V= PO 2020 DREAD , X, 2030 DREAD 1, L 2040 t1AT >1=:1-L 2050 LET C=D=J= 2060 FOP K=70 "'O 450 2070 LET C=tH!O

IF C<D THE'l 2! 0 2090 LET D= 2095 LET J=K 2! >!EXT 2120 P~P,JT TAB< Q).,uBASE ~1/~";JJ'tt(u;o;u)u 2125 IF D<300 THEN 2 90 2126 LET V=!:lT<!OO*c·l l l/Dl 2 27 IF V<20 THEN 90 21 FOR K= 70 TO 450 2 ( ) 2 2 2 2 2

*

4-(lines

pro-

the program is the ( ines 680-1720).

(Dl

R 5

0.5ni - 5nf +

Oxygen hound carbon not affect R. Double-bonded oxygen

In bonds. 0. Snn to the

is equivalent Sulfur behaves in

forms

nitrogen the formula

+ 5 nn +

forms s provides three "extra" hydrogens. formula including all the discussed

+

0. 5). accommodate even-elec "j" is suhtrac ted from the right-hand side Its value is " for odd- and "0. 5" for even-electron ions.

calculates formulae and from equation (5) for the

+ + 79nhr +

2nc + 28nsi + l4nn

32ns

renrranging

+ +

2nsi - - 2R

After subtracting (6) from (5)

+

31 +

W9 - + + j ~ 34 + 78nbr +

+ l4nc + 30nsi

15nn+34np+

Value of the left-hand side lated in line 700

+

+

+

+

is determined the "apparent" masses of

procedural instructions. the right-hand side (

stored T(l )-T decreasing magnitude.

The are

arises when

empirical formulae The operates from of nitrogen atoms,

(unallocated mass/15, ine 940). the equation

(8)

If (¥!9-lSnn)/14 = U9 = 0(9) and

considered mass must be

If it is not, another

of

formula 1026) and,

, the isotope abun-abundanc ies calcula-

d is cussed in con nee tion

close the formulae loops. 0( array and the "Ring closed in line 1720. The

10)

Line and

and

The subroutine in lines 1825-1870 revises down maximum of atoms of elements, depending

allocated mass. is the current element, Kl is the next element, and K2 is the allocated mass.

Examples

dance 2 12. considered). Two (

z 235 and isotopic abun-' 236 16, 237 68, 238 , and

7 formulae (Br and Cl of fit (7). The

ies of were

-15-

ELANAL finds the following best fitting ~

l formulae out of a total of 135 examined:

Formula c H Br Cl

18 31 6 9 28 8 7 17 0 9

19 19 l 0 8

5 9 7

21 4 8

For a nonac hlor ion of tuna liver (Zitko formulae. The 3 best

5000 , C9H8BrC1 6

chlorocyclopentad iene and cyclopentad iene, (Sovocool et al. 1977) were The ies were the Br, Cl, were considered.

For the low intensity parent ion, 27 formulae had SUSQ..::. 10000. The "correct" formula had SUSQ 7900. Best fitting formulae were (1330) and (1450). For the m/z 267, had SUSQ ~ 1100. Eight other formulae a better fit,

giving the best fit at SUSQ 680. The parent ion had of

3000. On the other hand, ion corres-ponding to the best fit for the M ion, SUSQ The base cluster , be formed by retro Diels-Alder fragmentation,

had 41. This was the best t

add it

PROGRAM TAPE

This program reads from tape and prints written by ELANAL. The arrays (lines 100, the same as in ELANAL. The file is selected 105-1 5), the system is set for output (line 120), file name is read from tape and displayed. Goodness fit is selec 128). For formulae exceeding this only will be printed.

files ) are lines

In lines 130-455, the "header" information the file, including elements considered, masses, and operational instructions, is read and printed. Record reading starts in line 462. Il =

indicates that the next record is a smmnar the end of the file (lines 655-690).

Depending on the type of calculation specified in ELANAL (formula only or isotope calcn-lation), X( I) is either "0" or "!"

ve records (l number, D I is the 0 contains number of atoms formula, W2 is the number

( 1 ) .1 h ( l ) J ( 1 ~- ) ...

lCALLYu

.I 28.t 19-~

, ! , 2, 6, 24• 20,720, 5040> 320• 362880• 362 3· BE+? 250 DA:'A 4·79E+8,6·227E+9>8•715E+ 0•l·32l77E+J2,2·092E+l3

5 DATA 3·557E+l4>6•LHiJ2E+J5, l645E+ 7>2•4329E+ 8.5· E+ 9 252 DA'"A J, !24E+21>2•5852E+22> ·2045£+23> 1·551 2E+25, • 3292£+26 253 • 8889E+28·3·04888E+29>8•84!76E+30•2·65253E+32 2 54

55 56

2 57

8·22283£+33,2·63 3!E+35, ·68332E+36·2·95233E+38 • 0333! E+ 3· 71993£+4!, • 37637£+43, 5· 23023E+4ll

2·03988E+ll6, • 5915E+4?,3.345253E .. ll9• ·40 E+5 6· 5 3E+52•2• 5825E+5ll• 962£+56>5•502 E+57 2. 58623E+59> • 24139E+6l, • 8282E+62> 4 4 £+6 z

7-

LiS

-!

'd

+ )+

B<~Sl=B(A5)+A(A5l

375

THE·J 3&5

j/j

ThS

1495 FOR l=l TO A4-

5

) )

-21-

> ... · C l )jl F t ; ''(( 1

L IT"

FILE ... J

295 PEJ{j) <!33! @40: "1-i>JrlLYc <:: l ) l ) "

9

~~E~ ELECT?G~ Cl>

) ;

• H

'

-22-

";"

.J BER OF FORMULAE EYAM lNED" ________ .,

FlL

abundancies I,

program abundance of

'

' abundance.

are array of

, 10, stores isotopic contains the stable isotope abun­elements, and Y(2,15) is used to

store entc'red isotope abundancies. The arrays are filled as applicable lines

is entered in lines is calculated lines 7

bonds are calculated in line information is displayed (lines ) •

in the second

the first pass through the loops the array ightest isotopes of all elements (the

For example, for formula 4 9 array C are

' ,0, , respectively. All other rows This represents the formulA

2

-23-After the second pass

P1, lines 1285-1370 '

the

2 0 2 0 0 2

and represents the formula

The probab of 0.01 = 0.03256, this formula is

in innermost array is

(row 4) (row 9 (row 10)

3c I

is J X 0.98892 X

overall probability

On the next pass the array C becomes

2 2

0 0 2

0 0

(row 4) (row 9) (row

loop

and represents the formula 2 • The calculations continue as al isotopic formulae are constructed and their probabilities calculated.

The index AS lines !302-1305 determines the mass of the formulA relative to the (AS =

for the A ion, A5 = 2 for the +I ion, etc •.

The summed calculated abundanc ies, stored in array ized (lines 1455-1495 and displayed lines 511-1518). If observed ahun­dancies were entered, goodness of fit is calculated in lines 1550-1570, and the observed ahundancies are also displayed (lines 1587-1590).

The results may also be printed teletype lines 1620-!794 and 900-l Lines !900-l

contain a "graphic" subroutine for a more illustra­tive "graphic'' presentation on the teletype·

An example of ISOTOPE output for a biphenyl, , is given below. In addition to the formula, isotope distribution was entered as well. Consequently, the "goodness of fit" (SUSQ) was calculated and the observed isotope distribution was normalized and printed for comparison.

FORMULA c1 WEIGHT 358 R&OB R 358-------------------- )

360-------------------------------------3.4

362--------------------------------- 81. 363- 10.9 364-------------- 35.7 365- 4.7 366- 8.8 367- l.l 368-369- 0. l

SUSQ 28.15 NORMALIZED INPUT 358--------------------- 54. 359- 6. )60----------------------------------------36!-- !4. 362--------------------------------363-364-------------- 36 365- 2. 366-

*********************

1 ) ; : ( ,; ;,.

55 )

5

8 "hALOGE'E VE': ( 1 ),

2

>40320>362880,JS28800•3·99168E+7 , l·3377E+l2s2.692E+I3

4LI!"E+23• l· 551! 2E+25 ·048BBE+29•8·84!76E+30

0 ( ) ..

·95·0·0076· • 422 ·9976•3·99E-4•0· 199

Q2=2 THE:-J 540 520 "RI:n "BROM !\IE" 521 I:~P'l!T 0(2) 52 DR 526 DlP'l!:

5 l 535 53 6 5

55;3 55 560

PRl'lT

E"

E "

5) "Sl'LFT"l" 0 ( )

565 DRH~ "SlLICO'J OC6

I T 10

+ 9)+2*0(6)+3*0(5)+2-lJ2- (3)-0(2)-0(! )- (7)) "FOR FO'tt"JULH:" ucJ ... ";O<l );ut< ... HJ .. ";l.,J2;"K ... QJ ... ";Q(8_.);n:r\-BtfJ.,.u;Q(2_); "K ... CLJ..-o;Q(3);*'K+-FJ .... u; C?J;"X: ... IJ .... ";Q( );l!;{ ... :JJ-u; <9);

(5 (4)itrX.-SlJ-u; 6)

-- T I -I"

-25-

5

/j

7· 26: i 630 @40: "FORMULA"

nqiJT !!40:"C";O i0 112=0 ""'HE:''J 1645

?R 40:uHn; 1JJ2 IF 0( l=0 7H 1655

-26-

'2

(2 "

PROGRA~ ISOTOPE (cont'd

1650 PPPH li?40:"0";Q(8l 1655 lf 0<2 =0 THE~ !665 1660 PRINT i¥40:"BR";Q(2) 1665 If O< 3 l=0 THEN 675 1670 PRUT i40:"CL";0<3l 1675 IF 0<7>=0 THEN 1685 1680 PRINT @40:"F";0(7) 1685 IF 0<1>=0 THE~ 1695 1690 PRUT i!I40:"!";Q(l) 1695 IF 0(9)=0 THEN 1705 1700 PRI>JT i40:";4'';Q(9) 1705 IF 0(5)=0 THEN 1715 1710 PRINT i40:"P";Q(5) 1715 IF OC4l=0 THEN 1725 1720 PRIH i?40:"S"JOC4l 1725 IF 0<6>=0 THEN 1735 1730 PRINT i?40:"SI";OC6l 1735 oru:>JT 1!40:"\..'ElGHT ";V 1740 PRINT i40:"R&DB ";R 1745 FOR I=l TO 17

-27-

l 7 50 l F B < I ) < 0 • l A',>l D B ( I + I l < 0 • l T li l::>J l 7 7 0 1760 Y7=1NT<0·6*B<Ill 1761 GOSUB 1900 l 765 lEX': l 1770 If 02=2 THE:\1 1794 1771 PRINT i40:"SUSQ ";S! !772 PRHT 1!140:":-JO"!MALIZED E.J"UT" !775 FOR I=l TO Q7 1777 BC 1 >=YC2• 1) 1780 Y7=1NT<0·6*BC1)) 1782 GOSUB 1900 l 785 'JEYT 1 1794 !"RI:,lT i40: "********"'***"'****"'*" 1795 ?RINT i37•26:0 1800 !"RLH "ANOTHER FORMULA <1>- L'JD <2>" 1810 HJ?UT ,';)3 1&20 If Q3=! THEi'J 490 I 830 END 1900 PRINT i40:V+I-J; 1910 FOR J=4 TO Y7 1920 DRl:\IT if40:"-"; 1930 "JEXT J !940 PRINT ij40:D(l) l 9 50 RETtiR'J

ACKNOWLEDGMENTS

I thank Mr. Y~rcel Babineau for patience and initiative in repairing the Model 6100 Data System and for interfacing a teletype to the Tektronix Plot 50 System, Mr. Steven Bellis for advice on the intricacies of the Tektronix System, Ms. Ruth Garnett for excellent editorial assistance, Mrs. Jeanine Hurley and Ms. Brenda McCullough for skill­ful typing and arrangement of the report, Mrs. Madelyn Irwin and Miss !1arion Haley for meticulous proofreading, and Dr. J. F. Uthe and Mr. A. Sreedharan for comments.

Listing of Finnigan Basic version of ELANAL was kindly provided by Dr. P. E. Kavanagh.

REFERENCES

Kavanagh, P.E. 1980. Program for elemental analysis using low or medium resolution mass spectra. Org. Mass. Spectrom. lS: 334-335.

Sovocool, G. W., R. G. Lewis, R. L. Harless, N. K. Wilson, and R. D. Zehr. !977. Analysis of technical chlordane by gas mass spectrometry. Anal. Chern. 49:

Wright, L. H., R. G. Lewis, H. L. Crist, G. W. Sovocool, and J. M. Simpson. 1978. The identification of polychlorinated terphenyls at trace levels in human adipose tissue by gas chromatography mass spectrometry. J. Anal. Toxicol, 2: 76-79.

Zitko, V. 1980. PCB's and other organochlorine compounds in sharks and tunas. ICES, C.M. l980/E:2l, Marine Environmental Quality Committee.

-28-