Frequently Asked Questions and Guidelines for Scintillation Vials

📦 Introduction

Scintillation vials are small sample containers suitable for liquid scintillation counting, primarily for the detection of radioisotopes. As a sample container in liquid scintillation counting for measuring the activity of radioactive samples, it is widely used in the fields of nuclear medicine, environmental monitoring, biochemistry, drug discovery and development.

This article answers common questions about scintillation vials to help users better select, use and maintain them to improve experimental efficiency and accuracy.

📦 Scintillation Vials Frequently Asked Questions

Material Selection

Glass vs. Plastic

Glass

- Advantages: High transparency, resistance to strong acid/alkali corrosion, excellent radiation resistance.
- Applicable scenarios: high-energy radioactive samples and experiments requiring long-term stability.

Plastic (e.g. polycarbonate PC or polyethylene PE)

- Advantages: lightweight, impact resistant, unbreakable.
- Applicable scenarios: low energy beta radioactive samples and short-term experiments.

Low-potassium Glass vs. Ordinary Glass

- Low Potassium Glass: Potassium oxide content is less than 1%, which significantly reduces the beta decay background of sodium isotopes (Na⁺) and is suitable for ultra-low level radioactivity measurements.
- Ordinary glass: contains higher potassium, may introduce additional radiation signals, and needs to be selected according to the sensitivity of the experiment.

Selection Guide

Material Matching

- High-energy/corrosive samples Low-potassium glass
- Low energy/easy handling samples Plastic or lightweight glass

Volume Selection

- Common sizes: 6 ml (microanalytical), 12 ml (routine), 20 ml (high sensitivity).
- Recommendation: Allow 20% space according to sample volume to avoid evaporation of scintillation solution or sample spillage.

Sealing Comparison

- Threaded cap: Metal/plastic screw cap + PTFE sealing ring, good air tightness, suitable for vacuum or low temperature experiments.
- Snap-on lid: one-time press seal, easy to operate, but easy to aging in long-term storage, need to replace the gasket regularly.

Cleaning and Reuse

Reusability

- Glass bottles: can be reused 5-10 times (depending on experimental requirements), need to be thoroughly decontaminated to avoid cross-contamination.
- Plastic bottles: single use recommended, less resistant to organic solvents.

Cleaning process

- Solvent cleaning: Remove radioactive residues with acetone/isoacetone, then rinse with deionized water.
- Ultrasonic cleaning: 30 minutes (40khz) to enhance surface particle removal.
- Drying: 180°C hot air circulation for 2 hours to ensure no VOC residue.

Risk Control

- The background needs to be detected by gamma energy spectrum before reuse;
- New bottles are recommended for high sensitivity experiments.

Anti-leakage Strategy

Key Measures

- Seal optimization: Select threaded rings containing fluorine rubber (FKM) seals that are resistant to acids, alkalis and organic solvents.
- Tightening specification: manually tighten until no loosening (to avoid excessive force leading to glass stress cracking, torque ≤ 2N-m is recommended.
- Pre-testing procedure: Use helium mass spectrometer to verify the sealing, or fill water and invert to observe air bubbles.

Background Interference Suppression

Interference source analysis

- Vials: Uranium-based nuclides, thorium-based nuclides in glass.
- Scintillation fluid: 2,5-diphenyl oxazole (PPO) may contain traces of radioactive impurities.
- Environment: laboratory gamma radiation background.

Solution

- Low background bottles: Use ultra-low uranium glass (U content <1ppm) or plastic bottles.
- Scintillation solution purification: Prepare scintillation solution using distilled water and add bursting agent.
- Shielding measures: Cover the experimental bench with lead plates (thickness ≥3mm) to reduce the influence of external radiation.

Storage Norms

Short-term storage

- Temperature: 15-25°C. Avoid temperature fluctuations that cause thermal expansion and contraction of the glass.
- Environment: Keep away from strong electromagnetic fields (e.g. MRI equipment)

Long-term storage

- Seal check: Retighten the cap every 6 months to prevent deterioration of the sealing material.
- Radioactive samples: store in lead boxes classified according to regulations, labeled with activity and half-life.

Waste Disposal

Radioactive waste liquid

- To be disposed of by a professional organization, following the Regulations on the Safe Management of Radioactive Waste (China) or similar regulations.

Non-radioactive waste liquid

- Chemical classification: scintillation liquids containing hydrogen halide need to be collected separately (flammable), and the rest are treated as organic waste liquids.
- Glass bottles: recycled as ordinary glass after cleaning, plastic bottles need to confirm material recyclability (e.g. PET marking).

📦 Tips and Precautions for Using Scintillation Vials

1. Considerations for sample preparation

Ratio of sample to scintillation solution

- Typical sample-to-scintillation solution ratios are 1:10 to 1:20 by volume, depending on the type of sample and the nature of the scintillation solution.
- Ensure that the sample is well mixed with the scintillation fluid to avoid localized over- or under-concentration.

Methods to avoid air bubbles

- When adding the scintillation fluid, inject slowly to minimize bubble formation.
- When using pipettes or syringes, avoid rapid aspiration or removal of liquid.
- Gently shake or rotate the vial after mixing to avoid violent shaking.

2. How to improve counting efficiency？

Choosing the right scintillation fluid

- Choose the appropriate scintillation solution according to the type of sample, e.g. water-soluble samples choose water-soluble scintillation solution, fat-soluble samples choose organic scintillation solution.
- Consider the chemical compatibility and counting efficiency of the scintillation solution.

Optimize the mixing of sample and scintillation solution

- Ensure that the sample is well mixed with the scintillation solution to avoid stratification or precipitation.
- Use a vortex mixer or ultrasonic processor to aid in mixing.
- For difficult-to-solve samples, heat or extend the mixing time as appropriate.

3. Common Troubleshooting

Possible causes and solutions for abnormal counting results

- Causes: Uneven mixing of sample and scintillation solution, aging of scintillation solution, improper calibration of instrument.
- Solution: Re-mix the sample, replace the scintillation solution, re-calibrate the instrument.

Emergency response to bottle breakage or leakage

- Cause: Bottle quality problem, improper operation, excessive temperature change.
- Solution: Immediately stop the test, place the broken or leaking bottle into a leak-proof container, clean up the test area and replace the bottle with a new one.

Proper use of Scintillation Vials requires attention to sample preparation, mixing ratios, bubble control, scintillation solution selection and mixing method optimization. In the event of abnormal counts or bottle breakage, the cause should be investigated and appropriate measures taken.

📦 Market Options for Scintillation Vials

1. How to choose cost-effective products

Choose according to the experimental needs and budget

- Experimental needs: choose the right scintillation vials according to the type of sample (water-soluble, fat-soluble, etc.) and the scale of the experiment (small-scale experiments or high-throughput screening).
- Budget control: under the premise of meeting the experimental needs, false it is reasonably priced products. Avoid blind pursuit of high-end brands, prioritize the balance between performance and price.
- Compatibility: Ensure that the scintillation vials are compatible with the scintillation solution and the instrument to avoid experimental failures or extra costs caused by mismatch.

Bulk purchase discounts and intentional matters

- Many suppliers offer bulk purchase discounts. It is recommended to make bulk purchases based on the long-term needs of the laboratory to reduce costs.
- Caution: Confirm the supplier’s reliability and product quality to avoid purchasing inferior products due to low price. Check the shelf life of the product to ensure that it is used within the expiration date. Understand the return and exchange policy, Party B’s products do not meet the demand can be dealt with in a timely manner.

2. Recommendations for other market options

Brand and supplier selection

- Choose well-known brands or reputable suppliers to ensure product quality and after-sales service. Refer to peer recommendations or user evaluations to understand the actual use of the product.

Environmental Protection and Sustainability

- Choose recyclable or reusable scintillation vials to minimize the impact of experimental waste on the environment. Consider the supplier’s environmental policy to support green lab practices.

Customization Needs

- If the experiment has special needs (e.g., specific size, color or material), you can contact the supplier to customize the product, but need to confirm the cost and delivery time in advance.

Choosing cost-effective scintillation vials requires comprehensive consideration of experimental needs, budget, bulk discounts and supplier reputation. Through proper planning and bulk purchasing, costs can be reduced while maintaining quality, while focusing on environmental protection and customization needs to further enhance experimental efficiency and sustainability.

📦 Conclusion

Scintillation vials are indispensable tools for radioactivity detection and liquid scintillation counting experiments, and their quality and the way they are used directly affect the accuracy and reliability of the results. Whether for biomedical research, environmental monitoring or nuclear physics, scintillation vials play a key role. As an important safeguard for the success of experiments, their proper selection and use requires a combination of experimental needs, cost-effectiveness and operational practices.

In the future, higher sensitivity, lower background, biodegradable or reusable scintillation vials may be available to further improve the accuracy of experimental data and reduce the impact of experimental waste on the environment.