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Fortran IV program for automatic external standardization in liquid scintillation spectrometry
International Journal of Applied Radiation and Isotopes, 1967, Vol, 18, pp. 247-252. Pergamon Press Ltd. Printed in Northern Ireland
Fortran IV Program for Automatic External Standardization in Liquid Scintillation Spectrometry* J . L. S P R A T T t a n d G. L. LAGE** Department of Pharmacology, College of Medicine, University of Iowa, Iowa City, Iowa The F O R T R A N IV computer program referred to as A U T D P M and described in Int. J. appl. Rad. Isotopes 16, 439 (1965) has been extensively modified and extended to incorporate the automatic computation of quench correction using automatic external standardization. This allows for the accumulation of data in the final disintegrations per minute form without the additional sample handling and second counting necessitated by the internal standard technique. The samples likewise are not contaminated with the internal standard radioisotope and may be re-claimed for further uses. The new program (AUTAES) will additionally still perform all of the functions of the A U T D P M program except that it is limited to a total of 5 counting cycles rather than I0 cycles per group of samples. LE P R O G R A M M E D U F O R T R A N I V P O U R LA N O R M A L I Z A T I O N E X T E R I E U R E A U T O M A T I Q U E DANS LA S P E C T R O M E T R I E DE SCINTILLATION LIQUIDE On a largement modifi6 et 6tendu le programme du calculateur F O R T R A N IV, nommd A U T D P M et ddcrit dans Int. J. appl. Rad. Isotopes 16, 439 (1965), afin d'y incorporer le calcul automatique de la correction pour l'extinction avec l'emploi de la normalization ext~rieure automatique. Ceci permet l'accumulation des donndes dans la forms ultime de ddsintdgrations par minute sans la manipulation suppl~mentaire et le deuxi~me comptage que n~cessite la technique de l'6talon int6rieur. De m~me les 6chantillons no sont pas contamin6s par le radioisotope de l'6talon intdrieur et ils peuvent ~tre rdcupdrds pour autres emplois. D'ailleurs, le nouveau programme (AUTAES) continuera ~ achever toutes les fonctions du programme A U T D P M sauf qu'il est limit6 ~ un total de 5 cycles de comptage plut6t que 10 cycles par groupe d'6chantillons. HPOFPAMMA F O R T R A N I V ~ [ I l t ABTOMATHqECHOITI BHEIIIHEFI HAJIFIBPOBHH B H{H~HOCTHOFI CIIHHTHJIJIFIIIHOHHOFI CHEKTPOMETPHH HporpaMMa F O R T R A N I V ~JIa Bt,IqIICJII,ITeJIBHOi~ Mamnm,i, I~aBeCVHa~ i~aK A U T D P M x~ OllnCaHHa~ B Int. J. appl. Rad. Isotopes 16, 439 (1965) 6LiJia 8Ha,tnTeJi~,~io mt~On3MeNelta ~t pacmnpeHa c IIeJimo BK~ImqeH~Ia aBTozaTHqeeKoro m,i,tnc~ieH~a nonpaBoK Ha ramemte, IICHO~IBSyH aBTOMaTHqeCHyIO BHemHIOIOI~azm6poBI~y. DTO IlOaBOalaeT noJIyqavB pe3yJIBTaT1,I B HOHetlHOA(~opMe pacllaJ~oB B MtlHyTy 6e3 AonoJIHnTeJILnoro MaHIalIyJII~pOnaHHao6pa3IlOM II BTOpllqltOrO
IiO~crteTa, qTO Ileo6x0~HMO IIpH IICIIOJIBBOBattIII, I BHyTpeHH81~ Ha3IIl6pOBHrI.
HpoMe woro, o6pa3i~Li He 3arp~sHamTCa BHyTpeHH~IMeTaI~/IapTHnlMpa)u~OH30TOIIOM ~I MoryT 6taTl, npnr0~H~I ~ I a ~a~II,He~mero ncnom,~oBamm. HOBa~ nporpaMMa (AUTAES) 5yAeT BI~IIIO.TIHItTBBce {~ytIHL~HHA U T D P M nporpaMibi, 3a I~CI~iioqenrleMTOr0, qTO olta orpaHi~e~Ia 5 IIO~CtIeTHBIMIIllIIHJIaill BMeCTO 10 Ha rpynl~y 06pasIlOB. * Supported by U.S. Public Health Service Research Grants GM-09784 and NB-04925. t Research Career Development Awardee of U.S. Public Health Service (GM-K3-5271) and Markle Scholm in Academic M e d i c i n e . ++Supported by U.S. Public Hea]th Service Training Grant 5T1-GM-141. 247
248
J. L. Spratt and G. L. Lage
FORTRAN IV PROGRAMM F U k AUTOMATISCHE EXTERNE NORMIERUNG IN F L O S S I G E I T S S Z I N T I L L A T I O N S - S P E K T R O M E T R I E Das mit A U T D P M bezeichnete und im Int. J. appl. Rad. Isotopes 16, 439 (1965) beschriebene F O R T R A N IV Rechenprogramm ist weitgehend ver~indert und erweitert worden, um die automatische Berechnung der LCschkorrektion unter Verwendung automatischer externer Normierung einzubeziehen. Dies ermCglicht die Ansammlung yon Daten in der endgiiltigen Zerf'a]le-je-Minute Form ohne die Notwendigkeit yon zusiitzlichen Probenhantierungen und wiederholtem Ziihlen wie bei der genormten internen Methode. Die Proben werden auch nicht mit dem genormten internen Radioisotop verseucht und kCnnen ffir andere Zwecke wiedergewonnen werden. Das neue Programm (AUTAES) wird zus~tzlich noch alle Funktionen des A U T D P M Programms erftillen, mit einer Ausnahme, dass es auf im ganzen 5 Z~hlspiele anstelle von 10 Spielen je Probengruppe beschr~inkt ist. AUTAES
TEST DECK
********** DATA FOR LOG BOOK **********
RED BACKGROUND (TRITIUM) = 1 5 . 4 7 CPM FOR 30.00 MINUTES GREEN BACKGRQUND |CARBON) = 2 6 . 6 7 C P M FOR 30.00 MINUTES BLUE B A C K G R O U N D = [ 7 . 5 3 C P M FOR 30.00 MINUTES T R I T I U M EFF = 0 . 2 7 1 3 4 C A R B O N EFF = O . 7 4 8 8 1 N U M B E R S A M P L E S = 34 AES
B L U E C P M { X ) A N D PER C E N T 171914. 1.0084060 122961. 0.7759155 92217. 0.5808577 50246. 0.3162208 26504. 0.1755491 I4192. 0.1157656 5605. 0.0730455
SEEN(Y)
FOR
TRITIUM
TRITIUM COEFFICIENTS i 0 . 9 9 8 8 7 3 E O0 0.349790E-01 0.579135E-05 I 0.9988730 0.0349790 0.0000058 2 0 . 9 9 9 1 8 7 E O0 0.231973E-01 0.633589E-05 -0.319381E-1I 2 0.9991865 0.02319/3 0.0000063 -0.0000000 3 0 . 9 9 9 9 8 8 E O0 0.505528E-01 0.405677E-05 0.300545E-10 3 0.99998/8 0.0505528 0.0000041 0.0000000 -0.0000000
AES BLUE CPM[X) AND PER CENT SEEN[Y) 162866. 0.9991947 124333. 0.9170850 86369. 0.7923560 49998. 0.5549265 27647. 0.3476734 14260. 0.205/928 5478. 0.[027953
-0.123507E-15
FOR CARBON
CARBON COEFFICIENTS I 0 . 9 6 6 2 1 1 E O0 0 . 1 7 2 7 9 0 E gO 0.575495E-05 l 0.9662710 0.1727902 0.0000058 2 0 . 9 9 9 3 8 2 E O0 0.478086E-01 0.I17065E-04 2 0.9993816 0.0478086 O.O000II7 -0.0000000 3 o . g 9 9 8 9 5 E O0 0.269757E-01 0.135066E-04 3 0.9998949 0.0269757 0.0000135 -0.0000000
-0.364185E-I0 -0.644514E-10 O.O000000
0.111175E-15
FIG. I. Example output of AUTAES program with automatic quench correction. Data for log book.
INTRODUGTION T w o recent developments which can greatly facilitate radioisotope determinations in liquid scintillation spectrometry are automatic external standardization (1'~> and the utilization of
c o m p u t e r techniques in d a t a handling. ~3-6) External standardization is a form of nondestructive testing as c o m p a r e d to the internal s t a n d a r d technique since the samples are not c o n t a m i n a t e d with an extraneous a m o u n t ot
Fortran IV program for automatic external standardization in liquid scintillation spectrometry
249
I.OIE O0 9q5E-OI 8"21E- OI 7"28E-01
~
6-34E- OI
E 4-
5.41E-01
h~- 4 - 4 7 E - OI 3-54E-01 2.60E-01 1.67E-01 7.30E-02
I f I I I I J I J I 3 3"89 E 0 4 7'21E04 bO5E05 l'39E05 1-72E05 5 " 6 0 E 0 2 " 2 2 E 045"55 E 0 4 8"88E04 1"22E 0 5 1.55E05 Min. X = 5 " 6 0 4 5 0 E 0 3 . M i n . Y = 7 - 3 0 4 5 5 E " 0 2 Mo~.X= 1"7]914E 0 5 Mox.Y= 1'00841E-00 Scales o n X : [ ' 6 6 3 0 9 E 0 4 on Y: 1.12243E-Olunif~/in
FIo. 2. Example output of AUTAES program with automatic quench correction. Plot of per cent tritium dpm seen on ordinate vs. AES (blue) channel cpm on abscissa. radioisotope. Since the usual time-consuming quench correction calculations must still be performed when external standardization is used, its potential becomes enhanced b y automatic computation techniques. This report describes a F O R T R A N I V computer p r o g r a m (AUTAES) which allows the utilization of automatic external standardization with m a chine collection of data and computation of results in quench-corrected d p m (disintegrations per minute). * METHODS T h e A U T A E S p r o g r a m has evolved from the A U T D P M p r o g r a m previously described (5). T h e A U T D P M program was written for data which was automatically punched onto cards by an I B M 026 card punch interfaced with the output from a Packard 3314 liquid scintillation spectrometer. A U T D P M p r o g r a m m e d multiple counting jobs of up to 200 samples and up to 10 counting cycles per job. Either first counts or second counts from internal standards could be computed. Quench corrections were also performed when the punched answer deck from • Copies of the program can be obtained by arrangement with J.L.S.
the first counts was submitted with the data cards from the internal standards counts. T h e computer was "informed" whether various sample groups were tritium or carbon by the simple expediency of leaving one or two open receptacles in the counter chain. Amplification of the following material m a y be obtained b y reference to the A U T D P M description c5). T h e A U T A E S program will perform all functions of the A U T D P M program by placing a 1 (first counts) or a 2 (second counts with internal standard added) in the appropriate column of the first control card. T h e only change has been the limitation to a m a x i m u m of 5 counting cycles per job rather than 10. Total counts of less than 1500 are treated as non-radioactive to retain the 95 per cent counting accuracy c7) as used previously. I f a 3 is placed in the aforementioned column of the first control card the following deck of data will be computed as before but the samples will be quench corrected by the external standard data. T h e liquid scintillation spectrometer channels are appropriately adjusted to monitor tritium in the red channel, carbon in the green channel, and the blue channel is used to monitor counts from the automatic external
250
J. L. Spratt and G. L. Lage 9 ' 9 9 E-OI 9"IOE-OI 8'20E-01 7-30E-0t "~ ¢k
6"41E-01
~ 5"51E-01 o 4"61E-01 o 3"72E-01
*
2"82E'01 1"92 E-Ot
Ii
[-03E -01 5-48E03
I l ] [ I F [ I I ! 3"70E 0 4 6.84E04 9-99 E 0 4 1-31E 0 5 1-63E05 2.12E 0 4 5.27E04 8"42E 04 H6E05 1-47 E 0 5 Min. X = 5 " 4 7 7 5 0 E 0 3 Min. Y= 1 . 0 2 7 9 5 E - 0 1 Max, X = I ' 6 2 8 6 6 E 0 5 Ma×.Y=9.99195E-OI Scales on X= 1 . 5 7 3 8 8 E 0 4 on Y= 1 - 0 7 5 6 8 E - 0 1 unify/in
FIG. 3. Example output of AUTAES program with automatic quench correction. Plot of per cent carbon dpm seen on ordinate vs. AES (blue) channel cpm on abscissa. standard source. In the data presented the red channel was set from 50 to 600 with a 50 per cent gain, the green channel was set from 100 to I000 with a 9.5 per cent gain, and the blue channel was set from 700 to infinity with a 4 per cent gain. A series of sealed tritium standards with the same dpm but varying degrees of quench and a similar series of quenched carbon samples are necessary for the q u e n c h curve computation. The chemical composition of the phosphor solution for each respective series of quenched standards should be the same as that used for the unknown samples. Sample n u m b e r one in the counter chain is always a sealed background and the program's o u t p u t always includes the data from this background monitor. The second sample is always the sealed tritium standard and the next sample is always the sealed carbon standard u p o n which the spectrometer efficiencies for the counting j o b are determined. W h e n tritium is to be c o m p u t e d with automatic external standardization, three chain receptacles are left empty and the sealed set of tritium standards follow. W h e n c a r b o n is to be computed with automatic external standardization, four chain receptacles
are left empty and the sealed set of quenched carbon standards follow. I f both tritium and carbon automatic external standardization are used during a run, the quenched carbon standards should always follow the quenched tritium standards with the open receptacle code as noted above. The unknown samples to be counted are then placed in sequence with one empty chain receptacle before groups of tritium samples and two empty chain receptacles before groups of carbon samples. The first control card submitted with each counting run includes the known dpm of the sealed standards in the second and third receptacles as well as the background count rate for each channel to be used in the computation. These b a c k g r o u n d s are submitted as fixed information since they are very stable with time and a spurious background count could negate all computations for a given run. I f automatic external standardization is being used, two additional control cards are used. Each of these states the known dpm of the series of quenched standards for either tritium or carbon. They also allow the investigator to select acceptable limits for the coefficients describing the quench
251
Fortran I V programfor automatic external standardization in liquid scintillation spectrometry AUTAES TEST DECK RED BACKGROUND (TRITIUM) = 15.47 CPM FOR 30.00 MINUTES GREEN BACKGROUND (CARBON) = 26.67 CPM FOR 30.00 MINUTES BLUE BACKGROUND = 17.53 CPM FOR 30.00 MINUTES TRITIUM EFF =0.27134CARBON EFF =O.74881NUMBER SAMPLES = 34 SAMPLE 7 8 9 I0
11 12 13 18 19 20 21 22 23 24 26 27 28 29 30 33 34 35 36 37 39 40 41 42 43
46 47 48 49 50
TRITIUM DPM 186557. 605214. 453069. 246652. 136928. 90297. 56976. O. O. O. O. O. O. O.
CARBON DPM O. O. O. O. O. O. O. 102917. 94460. 81613. 57157. 35810. 21197. 10588.
120165. 115276. 118357. 117863. 122018.
O. O. O. Oo O. 37938. 37299. 36435. 36628. 3668?. O.
0.9867210 0.8388171 0.6469269 0.5851980 0.5292448 1.0026860 0.9450892 0.863702I 0.8165724 0.7462816 0.2811723
165875. 134398. 102152. 92499. 83856. 166840. 133115. 105112. 93341. 78947. 44?44.
O. O. O.
0.2168331
33729. 30192. 24293. 20403. 43124. 34344. 29640. 24981, 20184.
O. O. O. OO. 106126. 10?337. 104050. 106021. 104904. O. O. O. O. O.
O. 31919. 31441. 31045. 30106. 30128.
PERCENT SEEN BLUE CPM 0.0000000 171914. 0.0000000 122961. 0.0000000 92217. 0.0000000 50246. 0.0000000 26504. 0.0000000 14192. 0.0000000 5605, 0.0000000 162866. 0.0000000 124333. 0.0000000 86369. 0.0000000 49998. 0.0000000 27667. O.O0000OO 14260. O.OOOO000 5478.
0.1910331 0.1650709 0.1447828 0.4984904 0.4193309 0.3735792 0.3258949 0.2742447
RED CPM 297139. 261409. 234024. 200053. 192258. 193989. 198044. 110025. 125253. 141255. 171263. 197250. 215395. 226794. 136719. 139582. 142264. 145701. 145952. 109419. 121557. 131588. 134642. 140394. 169557. 175555. 183296. 184606. 192506. 177729. 187501. 192026. 199074. 202893.
F1o. 4. Example output of AUTAES program with automatic quench correction. quench-corrected final data. curve and the limits of quench that he will accept in his unknown samples. This quench correction curve is computed by a polynomial to the third power which is calculated from the quenched standard data by the best least squares fit. RESULTS Printed output of all data followed by the sums of all sample data are available as with the A U T D P M p r o g r a m and are not shown here. This is followed by the log book data shown in Fig. 1. T h e coefficients are printed in both the "E" and the " F " format for each maximal power of x from 1 through 3 so that significant figures are always available in the output. T h e degree of the polynomial is followed by the correlation coefficient in each case. T h e next term is the
GRN CPM 28?090. 294358. 309312. 309862. 297119. 275232. 248332. 344658. 368405. 368792. 354295. 324894. 291828. 257186. 307452. 327664. 336363. 342533. 336485. 331920. 351341. 362239. 359490. 356342. 345201. 330948. 333810. 319898. 316184. 351691. 346320. 338195. 332126. 319061.
Output
of
constant which is followed by the powers of x. For example, the last two lines of the tritium coefficient data shows that for the third power o f x, the correlation coefficient is 0.9999878 and the curve of per cent tritium d p m seen (y) vs. AES channel cpm (x) can best be expressed as 0.0505528 + (0.405677 × 10-5)x + (0.300545 x 10-a°)x 2 - (0.123507 x 10-iS)x 8. Figs. 2 and 3 show tile tritium and carbon quench curves from the example data. Although the plotting subroutine for Figs. 2 and 3 is not in F O R T R A N , it is assumed that other computer centers will have similar subroutines that can be used instead. I f not, the data is available on the log book output sheet for graphing manually. I n either case, the program contains comments regarding the alteration or elimination of the plotting subroutine.
252
d. L. Spratt and G. L. Lage
T h e plotted curves are followed by the final data shown in Fig. 4 which states the corrected d p m of each unknown sample after it has been quench-corrected by the tertiary polynomial expression as described above. Since one would seldom need to save the two columns on the right, they can be cut off with the remaining sheet being of a convenient size for the usual 8½ × 11 in. ring binder or folder. DISCUSSION T h e A U T A E S program as described is being currently used on an I B M 7044 system with a substantial saving of time and effort. Since it can be used for the increasingly popular automatic external standardization while still retaining all of the features of the A U T D P M program, it is believed that it could be of reasonably general use. However, it should be noted that the program requires full F O R T R A N I V since it utilizes such features as the D a t a Statement. T h e p r o g r a m is still arranged to take "stacked" counting jobs so that various counting runs from different times or different laboratories can be processed at the same time. Although the time, error, and cost saving from one counting run is evident, such batch processing is even more economical. In addition, the batch processing allows for intermixing of counting runs with and without automatic external standardization. T h e ability to set one's own upper and lower
limits on the quench curve coefficients and the acceptable quench range is believed to offer significant flexibility to the individual investigator. W h e n initially instituting the use of the program with a given spectrometer, the limits can be avoided by the simple expediency of leaving four blank columns on the respective control cards. With additional data they can be appropriately selected and then implemented by punching either T R I T or CARB on the appropriate control card. Once acceptable limits are determined, the control cards need not change unless the limits are changed. Acknowledgment The authors are grateful for the cooperation of the University of Iowa Computer Center in the development of this program. REFERENCES 1. FLEISHMAND. G. and GLAZONOVV. V. Translation from Prib. Tekh. Eksp. No. 3, 55-58 (1962). 2. HIC.ASHIMURAT., YAMADA O., NOHARA N. and SHID~I T. Int. J. appl. Radiat. Isotopes 13, 308 (1962). 3. BLANCHARDF. A. Int. J. appl. Radiat. Isotopes. 14~ 213 (1963). 6. AXELROD L. R., MATTHIJSSEN C., GOLDZIEHER J. W. and PULLIA_MJ. E. Acta Endocrinol. Supplementum 99 (1965). 5. SI'RATTJ. L. Int. J. appl. Radiat. Isotopes. 16, 439 (1965). 6. MATTHIJSSENG. Analyt. Biochem. 15, 382 (1966). 7. JARR~TTA. A. AECU-262, Mort P-126, Technical Information Division, ORE, Oak Ridge, Tenn. (1946).
Fortran IV Program for Automatic External Standardization in Liquid Scintillation Spectrometry* J . L. S P R A T T t a n d G. L. LAGE** Department of Pharmacology, College of Medicine, University of Iowa, Iowa City, Iowa The F O R T R A N IV computer program referred to as A U T D P M and described in Int. J. appl. Rad. Isotopes 16, 439 (1965) has been extensively modified and extended to incorporate the automatic computation of quench correction using automatic external standardization. This allows for the accumulation of data in the final disintegrations per minute form without the additional sample handling and second counting necessitated by the internal standard technique. The samples likewise are not contaminated with the internal standard radioisotope and may be re-claimed for further uses. The new program (AUTAES) will additionally still perform all of the functions of the A U T D P M program except that it is limited to a total of 5 counting cycles rather than I0 cycles per group of samples. LE P R O G R A M M E D U F O R T R A N I V P O U R LA N O R M A L I Z A T I O N E X T E R I E U R E A U T O M A T I Q U E DANS LA S P E C T R O M E T R I E DE SCINTILLATION LIQUIDE On a largement modifi6 et 6tendu le programme du calculateur F O R T R A N IV, nommd A U T D P M et ddcrit dans Int. J. appl. Rad. Isotopes 16, 439 (1965), afin d'y incorporer le calcul automatique de la correction pour l'extinction avec l'emploi de la normalization ext~rieure automatique. Ceci permet l'accumulation des donndes dans la forms ultime de ddsintdgrations par minute sans la manipulation suppl~mentaire et le deuxi~me comptage que n~cessite la technique de l'6talon int6rieur. De m~me les 6chantillons no sont pas contamin6s par le radioisotope de l'6talon intdrieur et ils peuvent ~tre rdcupdrds pour autres emplois. D'ailleurs, le nouveau programme (AUTAES) continuera ~ achever toutes les fonctions du programme A U T D P M sauf qu'il est limit6 ~ un total de 5 cycles de comptage plut6t que 10 cycles par groupe d'6chantillons. HPOFPAMMA F O R T R A N I V ~ [ I l t ABTOMATHqECHOITI BHEIIIHEFI HAJIFIBPOBHH B H{H~HOCTHOFI CIIHHTHJIJIFIIIHOHHOFI CHEKTPOMETPHH HporpaMMa F O R T R A N I V ~JIa Bt,IqIICJII,ITeJIBHOi~ Mamnm,i, I~aBeCVHa~ i~aK A U T D P M x~ OllnCaHHa~ B Int. J. appl. Rad. Isotopes 16, 439 (1965) 6LiJia 8Ha,tnTeJi~,~io mt~On3MeNelta ~t pacmnpeHa c IIeJimo BK~ImqeH~Ia aBTozaTHqeeKoro m,i,tnc~ieH~a nonpaBoK Ha ramemte, IICHO~IBSyH aBTOMaTHqeCHyIO BHemHIOIOI~azm6poBI~y. DTO IlOaBOalaeT noJIyqavB pe3yJIBTaT1,I B HOHetlHOA(~opMe pacllaJ~oB B MtlHyTy 6e3 AonoJIHnTeJILnoro MaHIalIyJII~pOnaHHao6pa3IlOM II BTOpllqltOrO
IiO~crteTa, qTO Ileo6x0~HMO IIpH IICIIOJIBBOBattIII, I BHyTpeHH81~ Ha3IIl6pOBHrI.
HpoMe woro, o6pa3i~Li He 3arp~sHamTCa BHyTpeHH~IMeTaI~/IapTHnlMpa)u~OH30TOIIOM ~I MoryT 6taTl, npnr0~H~I ~ I a ~a~II,He~mero ncnom,~oBamm. HOBa~ nporpaMMa (AUTAES) 5yAeT BI~IIIO.TIHItTBBce {~ytIHL~HHA U T D P M nporpaMibi, 3a I~CI~iioqenrleMTOr0, qTO olta orpaHi~e~Ia 5 IIO~CtIeTHBIMIIllIIHJIaill BMeCTO 10 Ha rpynl~y 06pasIlOB. * Supported by U.S. Public Health Service Research Grants GM-09784 and NB-04925. t Research Career Development Awardee of U.S. Public Health Service (GM-K3-5271) and Markle Scholm in Academic M e d i c i n e . ++Supported by U.S. Public Hea]th Service Training Grant 5T1-GM-141. 247
248
J. L. Spratt and G. L. Lage
FORTRAN IV PROGRAMM F U k AUTOMATISCHE EXTERNE NORMIERUNG IN F L O S S I G E I T S S Z I N T I L L A T I O N S - S P E K T R O M E T R I E Das mit A U T D P M bezeichnete und im Int. J. appl. Rad. Isotopes 16, 439 (1965) beschriebene F O R T R A N IV Rechenprogramm ist weitgehend ver~indert und erweitert worden, um die automatische Berechnung der LCschkorrektion unter Verwendung automatischer externer Normierung einzubeziehen. Dies ermCglicht die Ansammlung yon Daten in der endgiiltigen Zerf'a]le-je-Minute Form ohne die Notwendigkeit yon zusiitzlichen Probenhantierungen und wiederholtem Ziihlen wie bei der genormten internen Methode. Die Proben werden auch nicht mit dem genormten internen Radioisotop verseucht und kCnnen ffir andere Zwecke wiedergewonnen werden. Das neue Programm (AUTAES) wird zus~tzlich noch alle Funktionen des A U T D P M Programms erftillen, mit einer Ausnahme, dass es auf im ganzen 5 Z~hlspiele anstelle von 10 Spielen je Probengruppe beschr~inkt ist. AUTAES
TEST DECK
********** DATA FOR LOG BOOK **********
RED BACKGROUND (TRITIUM) = 1 5 . 4 7 CPM FOR 30.00 MINUTES GREEN BACKGRQUND |CARBON) = 2 6 . 6 7 C P M FOR 30.00 MINUTES BLUE B A C K G R O U N D = [ 7 . 5 3 C P M FOR 30.00 MINUTES T R I T I U M EFF = 0 . 2 7 1 3 4 C A R B O N EFF = O . 7 4 8 8 1 N U M B E R S A M P L E S = 34 AES
B L U E C P M { X ) A N D PER C E N T 171914. 1.0084060 122961. 0.7759155 92217. 0.5808577 50246. 0.3162208 26504. 0.1755491 I4192. 0.1157656 5605. 0.0730455
SEEN(Y)
FOR
TRITIUM
TRITIUM COEFFICIENTS i 0 . 9 9 8 8 7 3 E O0 0.349790E-01 0.579135E-05 I 0.9988730 0.0349790 0.0000058 2 0 . 9 9 9 1 8 7 E O0 0.231973E-01 0.633589E-05 -0.319381E-1I 2 0.9991865 0.02319/3 0.0000063 -0.0000000 3 0 . 9 9 9 9 8 8 E O0 0.505528E-01 0.405677E-05 0.300545E-10 3 0.99998/8 0.0505528 0.0000041 0.0000000 -0.0000000
AES BLUE CPM[X) AND PER CENT SEEN[Y) 162866. 0.9991947 124333. 0.9170850 86369. 0.7923560 49998. 0.5549265 27647. 0.3476734 14260. 0.205/928 5478. 0.[027953
-0.123507E-15
FOR CARBON
CARBON COEFFICIENTS I 0 . 9 6 6 2 1 1 E O0 0 . 1 7 2 7 9 0 E gO 0.575495E-05 l 0.9662710 0.1727902 0.0000058 2 0 . 9 9 9 3 8 2 E O0 0.478086E-01 0.I17065E-04 2 0.9993816 0.0478086 O.O000II7 -0.0000000 3 o . g 9 9 8 9 5 E O0 0.269757E-01 0.135066E-04 3 0.9998949 0.0269757 0.0000135 -0.0000000
-0.364185E-I0 -0.644514E-10 O.O000000
0.111175E-15
FIG. I. Example output of AUTAES program with automatic quench correction. Data for log book.
INTRODUGTION T w o recent developments which can greatly facilitate radioisotope determinations in liquid scintillation spectrometry are automatic external standardization (1'~> and the utilization of
c o m p u t e r techniques in d a t a handling. ~3-6) External standardization is a form of nondestructive testing as c o m p a r e d to the internal s t a n d a r d technique since the samples are not c o n t a m i n a t e d with an extraneous a m o u n t ot
Fortran IV program for automatic external standardization in liquid scintillation spectrometry
249
I.OIE O0 9q5E-OI 8"21E- OI 7"28E-01
~
6-34E- OI
E 4-
5.41E-01
h~- 4 - 4 7 E - OI 3-54E-01 2.60E-01 1.67E-01 7.30E-02
I f I I I I J I J I 3 3"89 E 0 4 7'21E04 bO5E05 l'39E05 1-72E05 5 " 6 0 E 0 2 " 2 2 E 045"55 E 0 4 8"88E04 1"22E 0 5 1.55E05 Min. X = 5 " 6 0 4 5 0 E 0 3 . M i n . Y = 7 - 3 0 4 5 5 E " 0 2 Mo~.X= 1"7]914E 0 5 Mox.Y= 1'00841E-00 Scales o n X : [ ' 6 6 3 0 9 E 0 4 on Y: 1.12243E-Olunif~/in
FIo. 2. Example output of AUTAES program with automatic quench correction. Plot of per cent tritium dpm seen on ordinate vs. AES (blue) channel cpm on abscissa. radioisotope. Since the usual time-consuming quench correction calculations must still be performed when external standardization is used, its potential becomes enhanced b y automatic computation techniques. This report describes a F O R T R A N I V computer p r o g r a m (AUTAES) which allows the utilization of automatic external standardization with m a chine collection of data and computation of results in quench-corrected d p m (disintegrations per minute). * METHODS T h e A U T A E S p r o g r a m has evolved from the A U T D P M p r o g r a m previously described (5). T h e A U T D P M program was written for data which was automatically punched onto cards by an I B M 026 card punch interfaced with the output from a Packard 3314 liquid scintillation spectrometer. A U T D P M p r o g r a m m e d multiple counting jobs of up to 200 samples and up to 10 counting cycles per job. Either first counts or second counts from internal standards could be computed. Quench corrections were also performed when the punched answer deck from • Copies of the program can be obtained by arrangement with J.L.S.
the first counts was submitted with the data cards from the internal standards counts. T h e computer was "informed" whether various sample groups were tritium or carbon by the simple expediency of leaving one or two open receptacles in the counter chain. Amplification of the following material m a y be obtained b y reference to the A U T D P M description c5). T h e A U T A E S program will perform all functions of the A U T D P M program by placing a 1 (first counts) or a 2 (second counts with internal standard added) in the appropriate column of the first control card. T h e only change has been the limitation to a m a x i m u m of 5 counting cycles per job rather than 10. Total counts of less than 1500 are treated as non-radioactive to retain the 95 per cent counting accuracy c7) as used previously. I f a 3 is placed in the aforementioned column of the first control card the following deck of data will be computed as before but the samples will be quench corrected by the external standard data. T h e liquid scintillation spectrometer channels are appropriately adjusted to monitor tritium in the red channel, carbon in the green channel, and the blue channel is used to monitor counts from the automatic external
250
J. L. Spratt and G. L. Lage 9 ' 9 9 E-OI 9"IOE-OI 8'20E-01 7-30E-0t "~ ¢k
6"41E-01
~ 5"51E-01 o 4"61E-01 o 3"72E-01
*
2"82E'01 1"92 E-Ot
Ii
[-03E -01 5-48E03
I l ] [ I F [ I I ! 3"70E 0 4 6.84E04 9-99 E 0 4 1-31E 0 5 1-63E05 2.12E 0 4 5.27E04 8"42E 04 H6E05 1-47 E 0 5 Min. X = 5 " 4 7 7 5 0 E 0 3 Min. Y= 1 . 0 2 7 9 5 E - 0 1 Max, X = I ' 6 2 8 6 6 E 0 5 Ma×.Y=9.99195E-OI Scales on X= 1 . 5 7 3 8 8 E 0 4 on Y= 1 - 0 7 5 6 8 E - 0 1 unify/in
FIG. 3. Example output of AUTAES program with automatic quench correction. Plot of per cent carbon dpm seen on ordinate vs. AES (blue) channel cpm on abscissa. standard source. In the data presented the red channel was set from 50 to 600 with a 50 per cent gain, the green channel was set from 100 to I000 with a 9.5 per cent gain, and the blue channel was set from 700 to infinity with a 4 per cent gain. A series of sealed tritium standards with the same dpm but varying degrees of quench and a similar series of quenched carbon samples are necessary for the q u e n c h curve computation. The chemical composition of the phosphor solution for each respective series of quenched standards should be the same as that used for the unknown samples. Sample n u m b e r one in the counter chain is always a sealed background and the program's o u t p u t always includes the data from this background monitor. The second sample is always the sealed tritium standard and the next sample is always the sealed carbon standard u p o n which the spectrometer efficiencies for the counting j o b are determined. W h e n tritium is to be c o m p u t e d with automatic external standardization, three chain receptacles are left empty and the sealed set of tritium standards follow. W h e n c a r b o n is to be computed with automatic external standardization, four chain receptacles
are left empty and the sealed set of quenched carbon standards follow. I f both tritium and carbon automatic external standardization are used during a run, the quenched carbon standards should always follow the quenched tritium standards with the open receptacle code as noted above. The unknown samples to be counted are then placed in sequence with one empty chain receptacle before groups of tritium samples and two empty chain receptacles before groups of carbon samples. The first control card submitted with each counting run includes the known dpm of the sealed standards in the second and third receptacles as well as the background count rate for each channel to be used in the computation. These b a c k g r o u n d s are submitted as fixed information since they are very stable with time and a spurious background count could negate all computations for a given run. I f automatic external standardization is being used, two additional control cards are used. Each of these states the known dpm of the series of quenched standards for either tritium or carbon. They also allow the investigator to select acceptable limits for the coefficients describing the quench
251
Fortran I V programfor automatic external standardization in liquid scintillation spectrometry AUTAES TEST DECK RED BACKGROUND (TRITIUM) = 15.47 CPM FOR 30.00 MINUTES GREEN BACKGROUND (CARBON) = 26.67 CPM FOR 30.00 MINUTES BLUE BACKGROUND = 17.53 CPM FOR 30.00 MINUTES TRITIUM EFF =0.27134CARBON EFF =O.74881NUMBER SAMPLES = 34 SAMPLE 7 8 9 I0
11 12 13 18 19 20 21 22 23 24 26 27 28 29 30 33 34 35 36 37 39 40 41 42 43
46 47 48 49 50
TRITIUM DPM 186557. 605214. 453069. 246652. 136928. 90297. 56976. O. O. O. O. O. O. O.
CARBON DPM O. O. O. O. O. O. O. 102917. 94460. 81613. 57157. 35810. 21197. 10588.
120165. 115276. 118357. 117863. 122018.
O. O. O. Oo O. 37938. 37299. 36435. 36628. 3668?. O.
0.9867210 0.8388171 0.6469269 0.5851980 0.5292448 1.0026860 0.9450892 0.863702I 0.8165724 0.7462816 0.2811723
165875. 134398. 102152. 92499. 83856. 166840. 133115. 105112. 93341. 78947. 44?44.
O. O. O.
0.2168331
33729. 30192. 24293. 20403. 43124. 34344. 29640. 24981, 20184.
O. O. O. OO. 106126. 10?337. 104050. 106021. 104904. O. O. O. O. O.
O. 31919. 31441. 31045. 30106. 30128.
PERCENT SEEN BLUE CPM 0.0000000 171914. 0.0000000 122961. 0.0000000 92217. 0.0000000 50246. 0.0000000 26504. 0.0000000 14192. 0.0000000 5605, 0.0000000 162866. 0.0000000 124333. 0.0000000 86369. 0.0000000 49998. 0.0000000 27667. O.O0000OO 14260. O.OOOO000 5478.
0.1910331 0.1650709 0.1447828 0.4984904 0.4193309 0.3735792 0.3258949 0.2742447
RED CPM 297139. 261409. 234024. 200053. 192258. 193989. 198044. 110025. 125253. 141255. 171263. 197250. 215395. 226794. 136719. 139582. 142264. 145701. 145952. 109419. 121557. 131588. 134642. 140394. 169557. 175555. 183296. 184606. 192506. 177729. 187501. 192026. 199074. 202893.
F1o. 4. Example output of AUTAES program with automatic quench correction. quench-corrected final data. curve and the limits of quench that he will accept in his unknown samples. This quench correction curve is computed by a polynomial to the third power which is calculated from the quenched standard data by the best least squares fit. RESULTS Printed output of all data followed by the sums of all sample data are available as with the A U T D P M p r o g r a m and are not shown here. This is followed by the log book data shown in Fig. 1. T h e coefficients are printed in both the "E" and the " F " format for each maximal power of x from 1 through 3 so that significant figures are always available in the output. T h e degree of the polynomial is followed by the correlation coefficient in each case. T h e next term is the
GRN CPM 28?090. 294358. 309312. 309862. 297119. 275232. 248332. 344658. 368405. 368792. 354295. 324894. 291828. 257186. 307452. 327664. 336363. 342533. 336485. 331920. 351341. 362239. 359490. 356342. 345201. 330948. 333810. 319898. 316184. 351691. 346320. 338195. 332126. 319061.
Output
of
constant which is followed by the powers of x. For example, the last two lines of the tritium coefficient data shows that for the third power o f x, the correlation coefficient is 0.9999878 and the curve of per cent tritium d p m seen (y) vs. AES channel cpm (x) can best be expressed as 0.0505528 + (0.405677 × 10-5)x + (0.300545 x 10-a°)x 2 - (0.123507 x 10-iS)x 8. Figs. 2 and 3 show tile tritium and carbon quench curves from the example data. Although the plotting subroutine for Figs. 2 and 3 is not in F O R T R A N , it is assumed that other computer centers will have similar subroutines that can be used instead. I f not, the data is available on the log book output sheet for graphing manually. I n either case, the program contains comments regarding the alteration or elimination of the plotting subroutine.
252
d. L. Spratt and G. L. Lage
T h e plotted curves are followed by the final data shown in Fig. 4 which states the corrected d p m of each unknown sample after it has been quench-corrected by the tertiary polynomial expression as described above. Since one would seldom need to save the two columns on the right, they can be cut off with the remaining sheet being of a convenient size for the usual 8½ × 11 in. ring binder or folder. DISCUSSION T h e A U T A E S program as described is being currently used on an I B M 7044 system with a substantial saving of time and effort. Since it can be used for the increasingly popular automatic external standardization while still retaining all of the features of the A U T D P M program, it is believed that it could be of reasonably general use. However, it should be noted that the program requires full F O R T R A N I V since it utilizes such features as the D a t a Statement. T h e p r o g r a m is still arranged to take "stacked" counting jobs so that various counting runs from different times or different laboratories can be processed at the same time. Although the time, error, and cost saving from one counting run is evident, such batch processing is even more economical. In addition, the batch processing allows for intermixing of counting runs with and without automatic external standardization. T h e ability to set one's own upper and lower
limits on the quench curve coefficients and the acceptable quench range is believed to offer significant flexibility to the individual investigator. W h e n initially instituting the use of the program with a given spectrometer, the limits can be avoided by the simple expediency of leaving four blank columns on the respective control cards. With additional data they can be appropriately selected and then implemented by punching either T R I T or CARB on the appropriate control card. Once acceptable limits are determined, the control cards need not change unless the limits are changed. Acknowledgment The authors are grateful for the cooperation of the University of Iowa Computer Center in the development of this program. REFERENCES 1. FLEISHMAND. G. and GLAZONOVV. V. Translation from Prib. Tekh. Eksp. No. 3, 55-58 (1962). 2. HIC.ASHIMURAT., YAMADA O., NOHARA N. and SHID~I T. Int. J. appl. Radiat. Isotopes 13, 308 (1962). 3. BLANCHARDF. A. Int. J. appl. Radiat. Isotopes. 14~ 213 (1963). 6. AXELROD L. R., MATTHIJSSEN C., GOLDZIEHER J. W. and PULLIA_MJ. E. Acta Endocrinol. Supplementum 99 (1965). 5. SI'RATTJ. L. Int. J. appl. Radiat. Isotopes. 16, 439 (1965). 6. MATTHIJSSENG. Analyt. Biochem. 15, 382 (1966). 7. JARR~TTA. A. AECU-262, Mort P-126, Technical Information Division, ORE, Oak Ridge, Tenn. (1946).