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Sample handling conveniences for activation analysis
International Journal of Applied Radiation and Isotopes, 1966, Vol. 17,
p p . 74-75. Pergamon Press Ltd. Printed in Northern Ireland
S~mple Ha~rlling Conveniences for Activation Analysis
(Received23 April
1965)
IN THE course of activation analysis studies at the Walter Reed A r m y Institute of Research reactor facility two experimental devices were found convenient in handling samples. (i) I n work with short-lived activities of about 10 see half-life, a convenient system was sought for quick transfer of samples from our pneumatic delivery system to the scintillation well crystal. Rather than a completely automated direct delivery system which would require more detailed engineering and a great deal of shoptime, a quick-opening rabbit which could be handled rapidly by one individual appeared to be suitable for our purposes. I n our present system the pneumatic tube delivery box in the counting room is approximately 5 ft from a dual-crystal system. The rabbit (Fig. 1) can be snapped open quickly with one Vl E'W# I
hand and a single sample delivered from the box to the crystal in essentially one motion in less than 3 see. An expendable plastic tube placed in the crystal prevents possible contamination of the crystal by the sample. This tube is flared at the top to a funnel shape to facilitate quick reception of the sample. The rabbit is constructed to contain either two 0.3-ml polyethylene tubes for simultaneous delivery to a two-crystal system, or one 1/2 × 1 in. polyethylene vial for use in a single-crystal system. The 0.3-ml tubes are spaced so that each can be dumped simultaneously into two expendable plastic tubes for placement in separate crystals. The operation from delivery box to the two-crystal system can be accomplished in about 4.5 see by one individual. The body of the rabbit is constructed entirely of Dupont Zytel 101 nylon resin. The replaceable washer ("O"-ring) which acts as an air seal in the pneumatic system is polyethylene. Radiation induced in the rabbit by exposures up to 36 see in a thermal neutron flux of approximately 10la n/cm~. see is not above tolerance when the rabbit is received in the counting room; however, the rabbit itself must be removed to minimize background interference. The construction of VIEWS3
VIEWS2
RABBIT IN OPEN POSITION
RABBIT IN CLOSED POSITION
RABBIT SEEN AT 90 ° FROM VIEWS lel2
~./-Replaceable VZ" Viol ~ml tube
Nipple
o
which eng a ge¢. opening when rabbit is in closed position
tubes or I vial can be held.
TOP VI EW
FIG. 1 74
Technical notes
75
Fio. 2. Cartridge belt for indexing and partitioning sample capsules. the rabbit is relatively simple; it is durable and shows no tendency to snap open while in the pneumatic system or upon impact in the delivery box. (ii) A"cartridgebelt"arrangement (Fig. 2) wasused to index sample tubes, to keep them together, and to protect and keep intact fragile sample tubes with slipfit caps. The cloth used to make the holder is generally worn-out, threadbare cotton sheeting or handkerchief material sewn with cotton or nylon thread. No contamination of the sample tube exteriors was observed, nor was the immediate nor residual radioactive level of the cartridge belt ever troublesome. G. C. BATTISTONE M. H. FELDMAN
Division of Nuclear Medicine Walter Reed Army Institute of Research Washington
International Journal of Applied Radiation and Isotopes, 1966, Vol. 17, p p . 75-77. P e r g a m o n Press Ltd. Printed in Northern Ireland
Control of the Radlocheznlcal Purity of Some Organic Radlopharmac e u t l c a l s L a b e l l e d w i t h I TM (Received 7 May 1965)
1. Introduction IN RADIOPHARMACEUTICALS,in addition to the radionuclide purity and chemical purity there is the important aspect of radiochemical purity. The latter term signifies that the radioactive atom is in the valency state desired, or in the form of the compound
desired. For example in sodium radioiodide I ~1 solutions the presence of I TM as iodate will constitute as a radiochemical impurity. I n organic molecules marked with I TM free-iodide, I TM will be a radiochemical impurity. The free-iodide concentration in solutions of Ilal-labelled organic compounds is dependent on specific activity, pH, temperature, mode and duration of storage. Therefore before employing them for physiological investigations it is imperative to examine the product for the radiochemical purity. The techniques most frequently used are chromatography, tl) and electrophoresist2) carried on ordinary chomatographic paper strips. I n the present study the author has examined the possibility of employing two anion exchange cellulose papers for the control of some organic radiopharmaceuticals.
2. Materials and methods The two ion-exchange cellulose papers used were Whatman paper AE 30 and DE 20* both in the free-base form. They are compared with the ordinary chromatography paper Whatman No. I. The following products, prepared in the Ddpartment des Radioelements, CEN, Saclay, were utilized in the present study: (a) aqueous solution of Rose-Bengal I TM (b) aqueous solution of erythrosine I TM (c) aqueous solution of diodone I TM (d) aqueous solution of hypaque I TM (e) solution of L-thyroxine 1laI in 50~o propylene glycol (f) aqueous solution of sodium radioiodide I TM. Note: These solutions were about two or three weeks old on the day of analysis and as a consequence * Manufactured by: W. and R. Balston Ltd., U.K.
p p . 74-75. Pergamon Press Ltd. Printed in Northern Ireland
S~mple Ha~rlling Conveniences for Activation Analysis
(Received23 April
1965)
IN THE course of activation analysis studies at the Walter Reed A r m y Institute of Research reactor facility two experimental devices were found convenient in handling samples. (i) I n work with short-lived activities of about 10 see half-life, a convenient system was sought for quick transfer of samples from our pneumatic delivery system to the scintillation well crystal. Rather than a completely automated direct delivery system which would require more detailed engineering and a great deal of shoptime, a quick-opening rabbit which could be handled rapidly by one individual appeared to be suitable for our purposes. I n our present system the pneumatic tube delivery box in the counting room is approximately 5 ft from a dual-crystal system. The rabbit (Fig. 1) can be snapped open quickly with one Vl E'W# I
hand and a single sample delivered from the box to the crystal in essentially one motion in less than 3 see. An expendable plastic tube placed in the crystal prevents possible contamination of the crystal by the sample. This tube is flared at the top to a funnel shape to facilitate quick reception of the sample. The rabbit is constructed to contain either two 0.3-ml polyethylene tubes for simultaneous delivery to a two-crystal system, or one 1/2 × 1 in. polyethylene vial for use in a single-crystal system. The 0.3-ml tubes are spaced so that each can be dumped simultaneously into two expendable plastic tubes for placement in separate crystals. The operation from delivery box to the two-crystal system can be accomplished in about 4.5 see by one individual. The body of the rabbit is constructed entirely of Dupont Zytel 101 nylon resin. The replaceable washer ("O"-ring) which acts as an air seal in the pneumatic system is polyethylene. Radiation induced in the rabbit by exposures up to 36 see in a thermal neutron flux of approximately 10la n/cm~. see is not above tolerance when the rabbit is received in the counting room; however, the rabbit itself must be removed to minimize background interference. The construction of VIEWS3
VIEWS2
RABBIT IN OPEN POSITION
RABBIT IN CLOSED POSITION
RABBIT SEEN AT 90 ° FROM VIEWS lel2
~./-Replaceable VZ" Viol ~ml tube
Nipple
o
which eng a ge¢. opening when rabbit is in closed position
tubes or I vial can be held.
TOP VI EW
FIG. 1 74
Technical notes
75
Fio. 2. Cartridge belt for indexing and partitioning sample capsules. the rabbit is relatively simple; it is durable and shows no tendency to snap open while in the pneumatic system or upon impact in the delivery box. (ii) A"cartridgebelt"arrangement (Fig. 2) wasused to index sample tubes, to keep them together, and to protect and keep intact fragile sample tubes with slipfit caps. The cloth used to make the holder is generally worn-out, threadbare cotton sheeting or handkerchief material sewn with cotton or nylon thread. No contamination of the sample tube exteriors was observed, nor was the immediate nor residual radioactive level of the cartridge belt ever troublesome. G. C. BATTISTONE M. H. FELDMAN
Division of Nuclear Medicine Walter Reed Army Institute of Research Washington
International Journal of Applied Radiation and Isotopes, 1966, Vol. 17, p p . 75-77. P e r g a m o n Press Ltd. Printed in Northern Ireland
Control of the Radlocheznlcal Purity of Some Organic Radlopharmac e u t l c a l s L a b e l l e d w i t h I TM (Received 7 May 1965)
1. Introduction IN RADIOPHARMACEUTICALS,in addition to the radionuclide purity and chemical purity there is the important aspect of radiochemical purity. The latter term signifies that the radioactive atom is in the valency state desired, or in the form of the compound
desired. For example in sodium radioiodide I ~1 solutions the presence of I TM as iodate will constitute as a radiochemical impurity. I n organic molecules marked with I TM free-iodide, I TM will be a radiochemical impurity. The free-iodide concentration in solutions of Ilal-labelled organic compounds is dependent on specific activity, pH, temperature, mode and duration of storage. Therefore before employing them for physiological investigations it is imperative to examine the product for the radiochemical purity. The techniques most frequently used are chromatography, tl) and electrophoresist2) carried on ordinary chomatographic paper strips. I n the present study the author has examined the possibility of employing two anion exchange cellulose papers for the control of some organic radiopharmaceuticals.
2. Materials and methods The two ion-exchange cellulose papers used were Whatman paper AE 30 and DE 20* both in the free-base form. They are compared with the ordinary chromatography paper Whatman No. I. The following products, prepared in the Ddpartment des Radioelements, CEN, Saclay, were utilized in the present study: (a) aqueous solution of Rose-Bengal I TM (b) aqueous solution of erythrosine I TM (c) aqueous solution of diodone I TM (d) aqueous solution of hypaque I TM (e) solution of L-thyroxine 1laI in 50~o propylene glycol (f) aqueous solution of sodium radioiodide I TM. Note: These solutions were about two or three weeks old on the day of analysis and as a consequence * Manufactured by: W. and R. Balston Ltd., U.K.