Introduction

Since its development in the mid-20th century, the liquid scintillation counting technique has become a cornerstone of research in the fields of nuclear physics, biomedical and environmental sciences. The core principle lies in the fact that energetic particles released during the decay of radionuclides interact with the scintillation fluid, converting the energy into visible photons. These photons are converted into electrical signals by photodetectors (e.g., photomultiplier tubes, PMTs), which are ultimately analyzed to quantify the amount of radioactive material.

Although the aura of liquid scintillation counting techniques is often focused on the detector or the scintillating liquid itself, the scintillation vials, as the containers that directly encapsulate the sample and the scintillating liquid, are a key hidden factor that determines the success or failure of an experiment.

The design of scintillation vials in the current study still faces challenges. The purpose of this paper is to systematically analyze the influence of the function and design of scintillation vials on their performance, and to provide researchers with theoretical basis and practical guidance in selecting and using scintillation vials by analyzing the function, optimizing the design, selecting the material, and improving the performance. At the same time, it looks forward to its future development trend, providing support for the further optimization and application expansion of LSC technology.

Overview of Liquid Scintillation Counting Technology

1. Basic Principle: Precision Chain for Energy Conversion

The core of liquid scintillation counting lies in the whole process of converting radioactive decay energy into optical signals through the scintillation liquid, and its technical process can be divided into radiation excitation, photon generation, optical signal capture, and data analysis.

2. Analysis of Key Technology Segments

• Stability control of scintillation solution: avoid hydrolysis (e.g. ethylene glycol-based scintillation solution needs to add antioxidant BHT) or photolysis (toluene-based solution needs to be stored away from light); part of the scintillation solution (e.g. ethylene glycol system containing PPO) is easy to absorb crystals at low temperatures (＜4℃), which will lead to a sudden drop in the efficiency of light output.

• Detector sensitivity optimization: new detection technologies such as silicon photodiodes with broad spectral response and low noise are suitable for weak light signal detection; multi-channel detector arrays can be combined with parallel signal processing to enhance the speed of high-throughput sample analysis.

• Sample encapsulation and purification: Sample encapsulation and purification: The hermeticity of the scintillation vials requires the helium mass spectrometry to pick up a leakage rate of less than 1×10-⁹ Pa-m³/s, preventing oxygen from penetrating to trigger oxidative degradation of the scintillation as well. Ion exchange resins can be used for cleaning to remove metal ions and reduce the background count rate. Zinc nitrate/potassium ferrocyanide is utilized to concentrate the radionuclides to a pelletized state, reducing the solution volume and increasing the encapsulation efficiency.

Liquid scintillation counting technology enables highly sensitive detection of low-energy radionuclides by converting the energy of radioactive particles into a light signal. Its performance depends on the optimization of key technical aspects such as the stability of the scintillation liquid, the sensitivity of the detector and the encapsulation and purification of the sample. As the core component of sample encapsulation, scintillation fluid plays an irreplaceable role in these links, and its design and material selection have an important impact on the overall performance of LSC technology.

Core Features and Design of Scintillation Vials

1. Container Functions

• Sealing: Scintillation vials need to have excellent sealing to prevent leakage of radioactive gases while avoiding external contaminants from entering the vial.

• Compatibility: Scintillation vials need to be compatible with a wide range of scintillation fluids to ensure that they do not chemically react or physically deform under prolonged contact.

2. Material Selection

• Glass: high transmittance to maximize photon transmission efficiency; excellent chemical stability, corrosion resistance, suitable for a wide range of scintillation fluids; low background count, suitable for high sensitivity detection. However, glass is fragile and heavy.

• Plastic: lightweight and impact resistant, easy to operate and transport. However, some plastics contain natural radionuclides and are chemically less stable and will react with some scintillation fluids.

• Surface Finishing: Materials such as silica are coated on the inner wall of the bottle to enhance light reflection and transmission efficiency and increase photon output.

3. Shape and Structure Optimization

• Bottle opening design: Narrow opening reduces liquid flow, reduces light scattering interference and improves signal consistency.

• Light avoidance: dark-colored bottle or coating can inhibit external light interference, reduce background noise and improve signal-to-noise ratio.

• Other optimized designs: scintillation vials with conical bottoms or special inner wall designs reduce sample residue and improve recovery rates; micro vials are suitable for micro sample testing, which can reduce the amount of scintillation solution and lower costs.

The design and material selection of scintillation vials has a significant impact on their performance. Detection sensitivity and accuracy of liquid scintillation counting can be significantly improved by optimizing sealing, compatibility, material selection, and shape and construction. In the future, with the application of new materials and technologies, the performance of scintillation vials will be further improved to provide stronger support for the development of LSC technology.

The Critical Role of Scintillation Vials

1. Enhanced detection sensitivity

• Low noise floor: Reduced introduction of radioactive impurities through material selection and sealing techniques, use of low-potassium borosilicate glass or high-purity plastics to reduce the content of natural radionuclides. Vacuum sealing or inert gas filling techniques are used to reduce the bursting effect of oxygen and moisture on the scintillation fluid.

• High energy efficiency: optimized bottle wall transmittance ensures maximum capture of scintillation light by the detector.

2. Guaranteeing experimental reliability

• Sample stability: long-term sealing to prevent volatilization or degradation, suitable for long time experiments. High quality cap seal design ensures that samples do not leak or contaminate during long term storage or transportation.

• Repeatability control: standardized container specifications reduce experimental errors between batches, and the use of scintillation vials of uniform size, shape and material ensures consistent experimental conditions.

3. Extended application scenarios

• Micro-volume detection: Micro scintillation vials support high-throughput sample analysis and are suitable for micro-volume sample detection, reducing reagent consumption and experimental costs.

• Extreme condition compatibility: Adopting high temperature resistant glass or special plastic material, it is suitable for special environment research autoclave sterilization or low temperature storage.

Scintillation vials enhance detection sensitivity through low background noise and efficient energy transfer in liquid scintillation counting technology, and also guarantee experimental reliability through sample stability and reproducibility control. In addition, the miniaturized and extreme condition compatible design further expands its application scenarios, providing strong support for research in the fields of nuclear physics, biomedicine and environmental monitoring. In the future, with the advancement of material science and manufacturing technology, the performance of scintillation vials will be further improved, laying a solid foundation for the innovation and application expansion of LSC counting.

Practical Application Examples

1. Biomedical field

• Quantification of radiotracer in radioimmunoassay: Radioimmunoassay (RIA) is a highly sensitive biomolecular detection technique widely used for quantitative analysis of hormones, drugs and tumor markers. Scintillation vials are used to hold radiolabeled antigen-antibody complexes and scintillation solutions, ensuring efficient detection of radiotracers through high transmittance and low background design.

2. Nuclear energy safety monitoring

• Trace detection of radioisotopes in nuclear waste: Nuclear waste contains a wide range of radioisotopes that need to be accurately monitored to ensure environmental safety. Scintillation vials are used to encapsulate nuclear waste extracts and scintillation fluids for radiographic detection, preventing leakage of radioactive materials through corrosion-resistant materials and hermetic seals.

3. Environmental science

• Tracking radionuclides in atmospheric aerosols: Radionuclides in atmospheric aerosols are important indicators for the study of atmospheric processes and environmental pollution. Scintillation vials are used to collect and detect radionuclides in aerosol samples, improving the detection sensitivity of low-activity samples through light-avoidance design and efficient energy transfer.

4. Other application areas

• Food safety: Scintillation vials can be used to detect radioactive contamination in food.

• Geological dating: dating by measuring radioactive isotopes in rocks and minerals.

• Drug discovery: scintillation vials are used for metabolic kinetic studies of radiolabeled drugs.

Scintillation vials have demonstrated their irreplaceable role in practical applications in fields such as biomedicine, nuclear safety monitoring and environmental science. Through high sensitivity, high stability and diversified designs, scintillation vials provide reliable support for radioactivity detection and promote research and technological progress in related fields. In the future, with the continuous expansion of application needs, scintillation vials will continue to play its unique value in more fields.

Challenges and Directions for Improvement

1. Existing limitations

• Fragile Glass Leads to Operational Risks: Although glass scintillation bottles are highly translucent and chemically stable, their fragility can lead to sample leakage or experimental interruption during transportation and use. This can lead to increased experimental costs, especially in high-throughput or automated experiments.

• Plastic may have aging problems: Plastic scintillation bottles ah long-term use or exposure to extreme conditions (such as high temperatures, strong acids and alkalis) may be aging, resulting in a decline in physical properties or chemical compatibility, which will reduce the reliability and reproducibility of experimental results.

• Background noise problem: Some plastic materials may contain natural radioactive impurities, which increase the background count and affect the detection sensitivity of low activity samples.

• Cost and environmental issues: High-quality glass or specialty plastic materials are costly, and single-use scintillation vials can be a burden on the environment.

2. Technological innovations

• Development of new composite materials: Combining the high chemical stability of ceramics and the impact resistance of plastics, we develop new ceramic-based composite materials that are resistant to high temperatures, corrosion, and low background noise, making them suitable for extreme conditions and high sensitivity detection. The development of biodegradable plastic materials reduces the burden on the environment and is suitable for disposable experiments, in line with the concept of sustainable development.

• Optimization of surface treatment technology: applying nanoscale optical enhancement coatings on the inner wall of bottles to improve photon transmission efficiency. Further enhance the detection sensitivity, suitable for micro-sample detection.

3. Optimization of surface treatment technology

• Nano-coating technology: nanoscale optically enhanced coatings are applied to the inner wall of the scintillation vials to improve photon transmission efficiency. This further enhances detection sensitivity and is suitable for trace sample detection.

• Anti-fouling coatings: Anti-fouling coatings have been developed to minimize sample residue and improve recovery rates for high value samples or reuse scenarios.

Although scintillation bottles play a key role in liquid scintillation counting technology, they still face certain challenges in terms of material properties, operational safety and environmental protection. The performance and application scope of scintillation vials can be significantly improved by research in various aspects. In the future, with the advancement of material science and manufacturing technology, scintillation vials will make greater breakthroughs in sensitivity, reliability and sustainability, injecting new vitality into the development of liquid scintillation counting technology.

Conclusions and Outlook

Scintillation vials, as the core component of liquid scintillation counting (LSC) technology, play an irreplaceable role in radioactivity detection through the continuous optimization and optimization of materials, structures and processes. Material innovation, structure optimization, process improvement and other optimizations are the core support tools for scintillation vials to become the liquid counting technology, which is widely used in biomedicine, nuclear energy safety monitoring, environmental science and other fields.

With the rapid development of material science, nanotechnology and automation technology, scintillation vials will achieve higher performance, smarter and more environmentally friendly design in the future. These innovations will not only promote the advancement of liquid scintillation counting technology, but also provide more powerful tools and support for research in the fields of nuclear physics, biomedicine, and environmental science. In the future, scintillation vials are expected to become a more efficient, reliable and sustainable core component of radioactivity detection technology.