Learn the complete SOP for UV Cabinet operation and calibration in pharmaceutical quality control. Step-by-step procedure, safety precautions, and FAQs included.
SOP for UV Cabinet
1.0 Purpose
The purpose of this Standard Operating Procedure (SOP) is to provide a clear and standardized method for the operation and calibration of a UV Cabinet used in quality control laboratories, ensuring accurate and reliable results during analysis.
2.0 Scope
This SOP applies to all quality control personnel involved in the operation of the UV Cabinet for sample visualization, especially during Thin Layer Chromatography (TLC) analysis.
3.0 Responsibilities
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Quality Control Officer / Executive
- Ensure proper operation of the UV Cabinet
- Perform calibration as per schedule
- Record observations accurately
- Follow safety precautions during use
4.0 Definitions and Abbreviations
- SOP – Standard Operating Procedure
- UV – Ultraviolet
- TLC – Thin Layer Chromatography
- nm – Nanometer
5.0 Materials Required
- Ethyl Alcohol
- Sodium Salicylate
- TLC Plates (Silica Gel G)
6.0 Safety Considerations
- Avoid direct exposure to UV radiation as it may cause skin burns and eye damage
- Always observe samples through the protective viewing glass
- Ensure the cabinet door is properly closed before switching on UV light
- Do not place any body part inside the chamber when UV light is ON
- Use appropriate PPE such as gloves and safety goggles
7.0 Procedure
7.1 Pre-Operational Checks
Before starting the UV Cabinet, ensure the following:
7.1.1 Verify that the UV Cabinet is clean and free from dust or residues
7.1.2 Check that UV lamps (254 nm and 366 nm) are functioning properly
7.1.3 Ensure the viewing glass is clean and not damaged
7.1.4 Confirm that the power supply is stable and properly connected
7.1.5 Ensure required materials (TLC plates, reagents) are ready
7.1.6 Wear appropriate Personal Protective Equipment (PPE) such as gloves and safety goggles
7.1 Operation of UV Cabinet
Follow the steps below for safe and effective operation:
- Ensure the working area and UV Cabinet are clean
- Switch ON the main power supply
- Turn ON the visible light switch
- Open the cabinet door
- Place the TLC plate inside the chamber
- Switch OFF the visible light
- Close the cabinet door securely
-
Turn ON the required UV wavelength:
- Short wave: 254 nm
- Long wave: 366 nm
- Observe the sample through the viewing window provided
- Record all observations carefully
- Switch OFF the UV light after use
- Open the cabinet and remove the TLC plate
⚠️ Important: Never expose skin or eyes directly to UV light during operation.
7.2 Calibration of UV Cabinet
Proper calibration ensures consistent and accurate UV detection.
7.2.1 Preparation of Standard Solutions
Prepare the following solutions using ethyl alcohol:
- 0.2% w/v Sodium Salicylate
- 0.4% w/v Sodium Salicylate
7.2.2 Preparation of TLC Plate
- Take a 10 × 10 cm TLC plate (Silica Gel G)
- Apply 5 µL of each solution
-
Maintain:
- Spot diameter ≈ 5 mm (corrected practical value)
- Distance between spots ≈ 3 cm
7.2.3 Drying
Allow the applied spots to dry completely at room temperature.
7.2.4 Observation
- Place the plate inside the UV Cabinet
-
Observe under:
- 254 nm UV light
- 366 nm UV light
- Record the visibility and intensity of spots
7.2.5 Acceptance Criteria
- Spots of 0.04% w/v concentration should be clearly visible under 254 nm
- Spots of 0.2% w/v concentration should be clearly visible under 366 nm
7.2.6 Calibration Frequency
- Calibration should be performed quarterly (every 3 months)
8.0 Key Notes for Better Performance
- Always clean the UV Cabinet before and after use
- Replace UV lamps as per manufacturer recommendations
- Maintain calibration records for audit purposes
- Ensure proper ventilation in the laboratory
Frequently Asked Questions (FAQs)
1. What is a UV Cabinet used for?
A UV Cabinet is used to visualize compounds on TLC plates under ultraviolet light in pharmaceutical and chemical laboratories.
2. What wavelengths are used in a UV Cabinet?
Common wavelengths include 254 nm (short wave) and 366 nm (long wave).
3. Why is UV Cabinet calibration important?
Calibration ensures accurate detection and reliable visualization of samples.
4. How often should a UV Cabinet be calibrated?
It should be calibrated quarterly (every 3 months).
5. What is the role of sodium salicylate in calibration?
It acts as a fluorescent standard to verify UV intensity and visibility.
6. Can UV light be harmful?
Yes, direct exposure can damage skin and eyes, so safety precautions are essential.
7. What is the purpose of visible light in a UV Cabinet?
Visible light helps in placing samples correctly before UV observation.
8. What type of plates are used in UV Cabinet analysis?
Typically, Silica Gel G TLC plates are used.
9. What should be done if spots are not visible?
Check UV lamp functionality, calibration status, and sample preparation.
10. Can the UV Cabinet be used without closing the door?
No, the door must be closed to prevent UV exposure and ensure accurate results.
