Key Tips for Using Scintillation Vials

Scintillation vials are an important tool used in laboratories to detect and measure radioactive substances in liquid samples. Proper selection and use can significantly affect the accuracy and reproducibility of experimental data. In radiological research, scintillation vials are used in conjunction with scintillation liquids to convert radioactive radiation into a measurable light signal, making them a central component in analytical techniques such as LSC.

The purpose of this article is to share tips on the selection and use of scintillation vials to help researchers optimize the experimental process, improve data accuracy, and reduce experimental errors.

1. Material selection

Glass vs. plastic (polystyrene, polyethylene, etc.)

• • Glass: chemical resistant, suitable for strong acids, alkalis and organic solvents, reduces fluorescence burst.
  • Plastic: lightweight and lower cost, suitable for water-based solutions and low corrosive samples, but some of them may not be compatible with organic solvents.

Suitable for different types of samples

• • Organic solvents: glass vials are recommended to prevent chemical degradation.
  • Aqueous solutions: plastic vials can be used to avoid unnecessary contamination and increased costs.

2. Volume and size

20ml vs. 7ml

• • 20ml: Suitable for large volume samples and standard LSC counting to increase sample dilution and reduce errors.
  • 7ml: Suitable for micro-volume sample analysis, reducing the amount of reagents, suitable for high sensitivity testing. (When sample volume is limited or radioactivity is low, small volume vials can increase counting efficiency and improve detection sensitivity.)

3. Type of cover

Screw cap vs. pressure seal cap

• • Screw cap: Better sealing, suitable for long time storage, preventing solvent evaporation.
  • Pressure Seal Lid: Suitable for short time experiments, easy to handle, but may not be suitable for volatile solvents.

Options to prevent volatilization and cross-contamination

• • Choosing a lid with a PTFE (polytetrafluoroethylene) gasket improves sealing and reduces the risk of solvent evaporation and cross-contamination.
  • Avoid reusing lids to minimize the impact of sample residue on subsequent experiments.

Proper selection of scintillation vials ensures accuracy of experimental data, improves experimental efficiency, and reduces experimental errors.

1. Sample solubility and compatibility

Precipitation or emulsification

• • The sample should be completely dissolved to avoid particulate matter affecting the counting efficiency.
  • Emulsification can interfere with optical signal transmission and can be resolved by changing the scintillation solution or using a co-solvent.

Selecting the right scintillation solution

• • For water-based samples, a scintillation solution suitable for polar solutions should be selected to ensure optimal energy transfer.
  • Organic solvent samples need to be matched with a compatible scintillation solution to avoid phase separation affecting detection.

2. Scintillation solution to sample ratio

Recommended optimal ratio (usually 1:10 or 1:4)

• • It is generally recommended to use 4-10 parts of scintillation solution per sample to ensure maximum photon detection.
  • Too little scintillator solution will reduce signal intensity and too much may affect the stability of the sample.

Factors affecting counting efficiency

• • The absorbance of the sample, the compatibility of the scintillation solution, and the adequacy of mixing all affect the final counting value.
  • High viscosity or high concentration samples may reduce counting efficiency and should be diluted appropriately.

3. Avoiding fluorescence bursts

Treatment options for color and chemical bursts

• • Color Burst: Dark-colored samples absorb photon signals and the effect can be reduced by appropriate dilution or replacement of the scintillation solution.
  • Chemical burst: Certain chemicals can interfere with the scintillation process. Anti-burst agents can be added or sample preparation can be optimized.

Selection of appropriate calibration method (external standard vs. internal standard)

• • External standards: Comparison using standard samples of known activity, suitable for comparison between different experimental conditions.
  • Internal standards: Add isotopes of known activity to the sample to compare signal attenuation and improve measurement accuracy.

Optimized sample preparation maximizes counting efficiency, reduces errors, and ensures stability and repeatability of experimental data.

1. Filling and sealing

Ensure no air bubbles to prevent sample evaporation

• • When adding sample and scintillation solution, operate slowly to avoid bubble formation to ensure uniform signal transmission.
  • Gently rotate or shake the mix rather than violently to prevent air bubbles from affecting counting accuracy.

Use automatic dispensers to minimize errors

• • The use of automatic pipettes or dispensers improves repeatability,, reduces counting manual errors, and ensures consistent sample volume in each vial.
  • For large sample volumes, it is recommended to use a multi-channel dispensing device to improve experimental efficiency.

2. Storage and Transportation

Avoid volume changes or degradation due to temperature changes

• • It should be stored in a constant temperature environment to avoid volume changes or degradation or density changes caused by temperature changes.
  • Before long time storage, sample stability can be tested to ensure the consistency of experimental data.

Safe storage requirements for shielding radioactivity test samples

• • Use special shielded containers to store radioactive samples to avoid exposure and radiation contamination.
  • Ensure that the laboratory complies with radioactive safety regulations, that storage areas are clearly labeled, and that waste is disposed of according to regulations.

3. Cleaning and reuse

Decontamination methods for glass bottles (acid washing, ultrasonic cleaning)

• • Acid washing method: Soak in dilute nitric acid or hydrochloric acid solution to remove residue, followed by ultrapure water rinsing.
  • Ultrasonic cleaning: In the ultrasonic cleaning instrument with the decontamination solvent, can effectively remove residual pollutants.

When to change vials to avoid cross-contamination

• • When vials show visible contamination, scratches or damage, they should be replaced immediately to avoid affecting experimental data.
  • Plastic vials are usually not recommended for reuse to avoid residual substances interfering with the detection of new samples.

The stability of experimental data can be ensured by proper handling and storage. Reduce errors and extend the life of scintillation vials.

1. Standard curve and background technical corrections

Setting of blank and standard reference samples

• • Before each experiment, the background count is determined using a blank sample (non-radioactive sample containing only scintillation solution), which has been excluded from environmental effects.

A standard curve is set up using a standard sample of known activity

• • Improve signal accuracy by subtracting background counts to avoid inadvertent inclusion of environmental noise in the experimental data.
  • For experiments with high background interference, additional shielding or optimized sample preparation can be used to reduce background noise.

2. Repeatability and error control

Setting the standard for repeated measurements

• • It is recommended to perform at least 3 repeated measurements for each sample and calculate the standard deviation to ensure data stability.
  • Whether the statistical coefficient of variation is within the acceptable range.

Monitor instrument drift and calibrate periodically

• • Periodically calibrate the liquid scintillation counter with a standard radioactive source to ensure instrument sensitivity and counting accuracy.
  • Monitor instrument drift during long-term experiments and adjust or maintain as necessary.

3. Experimental records and data management

Detailed records of vial types, sample preparation details

• • Record key parameters such as vial material (glass or plastic), scintillation solution type, sample concentration and ratio to ensure experimental reproducibility.
  • Label different experimental conditions for subsequent data analysis and comparison.

Improve data traceability with lab management software

• • Use electronic lab records (ELN) or lab management software (LIMS) to store data for easy tracking, analyzing and sharing of experimental results.
  • Combine with statistical software for data processing to ensure the reliability and scientificity of the results.

Through strict data quality control measures, experimental errors can be minimized, the accuracy and repeatability of experiments can be improved, and the reliability of research results can be ensured.

Choosing the right scintillation vials and scintillation solution is the key to improving the accuracy of the experiment. Depending on the type of sample, choose glass or plastic vials and make sure the scintillation solution is compatible with the sample to optimize counting efficiency. Proper handling and storage practices can reduce errors, such as avoiding air bubbles, emulsification and volatilization, ensuring vials are well preserved, and storing samples at the proper temperature and environment to maintain stability.

To improve overall data reproducibility, experimenters should follow best experimental practices, including optimizing sample filling, cleaning, and storage procedures to extend vial life while reducing experimental costs. By doing so, the accuracy of liquid scintillation counting can be improved, ensuring the reliability of the results and replacing the overall efficiency of the lab.

Last Updated: 2025/03/13

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