Nebulizers technetium

ICP-MS (inductively coupled plasma mass spectrometry) is frequently used for determining ultratrace amounts of technetium [9]. In spite of the high cost of the equipment, this detection method is far superior to other radiometric methods as regards sensitivity. When a double focussing high-resolution system is used (HR-ICP-MS) and an ultrasonic nebulizer is introduced [10], the detection limit is in the order 0.002 mBq. The ICP-MS method has been successfully applied to the determination of environmental "Tc as well as to other long-lived radionuclides of neptunium and plutonium in the environment. 

Clay and Clarke (209) compared administration of technetium in 0.9% saline using three different nebulizers, one with a particle size of 1.8, the other with one of 4.6, and the third with 10.3 pm. Lung deposition were 79, 59, and 44%, of the aerosol released from the nebulizer and deposited in the body, respectively. Methodological errors might have been introduced in that the radioaerosol released from the nebulizer was determined using weight measurements before and after inhalation. 

Vidgren and co-workers (219) studied six normal volunteers who inhaled 20 breaths of beclomethasone dipropionate liposomes labeled with technetium in the presence of SnCU as a reducing agent. Particles were inhaled from each of two nebulizers Aerotech II nebulizer and Spira nebulizer. Pulmonary deposition was 17 7% for Aerotech II and 14 3% for Spira nebulizer. At 3 hr, 93% of the deposited activity was detected in the volunteers breathing from the... 

Thomas and co-workers (221) have studied deposition of technetium-labeled human serum albumin particles, administered through a Siemens Servo 945 nebulizer system and a system 22 Acorn nebulizer unit. Total pulmonary deposition by percentage of the dose in the nebulizer was on the average 2.2%. There was considerable variability between subjects, with a coefficient of variation of 46%, but within subjects reproducibility was close, with a coefficient of variation of 15%. 

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