Detection Methods for Ethylene Oxide (EtO)

 

Ethylene Oxide (EtO) is a highly volatile and carcinogenic compound used in sterilization and fumigation processes. Due to its health risks, detecting its presence in food and environmental samples is crucial. The Food Safety and Standards Authority of India (FSSAI) has approved a method for detecting EtO and its reaction product, 2-Chloroethanol (2-CE), using advanced analytical techniques.

 

1. Gas Chromatography Tandem Mass Spectrometry (GC-MS/MS)

Principle:

• Gas Chromatography (GC) separates EtO from other sample components.
• Tandem Mass Spectrometry (MS/MS) detects and quantifies EtO and 2-CE using characteristic fragmentation patterns.

Variations in GC-MS/MS Techniques:

• Headspace (HS)-GC-MS/MS: Detects volatile compounds by analyzing gas phase above the sample.
• PTV or MMI-GC-MS/MS: Uses specialized injection techniques to enhance sensitivity.
• HS-Trap GC-MS/MS: Combines headspace analysis with a trapping system to increase detection limits.

Advantages:

✔ High sensitivity and specificity
✔ Capable of analyzing complex food matrices
✔ Simultaneous detection of both EtO and 2-CE

 

2. Headspace Gas Chromatography (HS-GC-MS)

Principle:

• Sample is incubated at a controlled temperature to allow EtO to evaporate.
• The gaseous phase is injected into the GC-MS system for separation and analysis.
• Mass spectrometry detects the ions of EtO and 2-CE and quantifies their concentrations.

Advantages:

✔ Minimizes sample handling and contamination
✔ Ideal for highly volatile compounds
✔ No need for extensive sample preparation

 

3. Multi-Step Enrichment Headspace-Trap GC-MS

Principle:

• Uses syringe-based headspace sampling combined with cryogen-free trapping to concentrate EtO.
• Multiple headspace injections ensure higher sensitivity.
• The enriched sample is analyzed via GC-MS.

Advantages:

✔ Extremely high sensitivity (detects very low concentrations)
✔ Suitable for various food matrices, including spices and cereals
✔ Avoids solvent interferences

 

4. QuEChERS Extraction with GC-MS/MS

Principle:

• Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) extraction isolates EtO and 2-CE from food samples.
• The extract is analyzed using GC-MS/MS.

Advantages:

✔ Effective for diverse food matrices
✔ Provides clean extracts with minimal sample degradation
✔ Validated according to international quality standards

 

Key Considerations in EtO Analysis

• Storage Conditions: Samples should be kept at ≤ 10°C to prevent volatilization.
• Use of Internal Standards: 1,2-Dichloroethane-d4 is used as a reference for precise quantification.
• Calibration Standards: EtO concentrations are measured against matrix-matched standards to ensure accuracy.
• Quality Control: Methods follow SANTE/11312/2021 guidelines to ensure reproducibility.

 

SOP: Procedure for Maintaining the Laboratory Log Book

  

1.0 PURPOSE

1.1 To lay down the procedure for maintaining the laboratory log book.

 

2.0 SCOPE

2.1 This SOP shall be applicable to all personnel working in the laboratory, including scientists and chemists.

 

3.0 RESPONSIBILITY

3.1 Scientists, chemists, and heads of departments shall be responsible for the implementation of this SOP.

 

4.0 DISTRIBUTION

4.1 The Quality Assurance (QA) department is responsible for keeping the SOP ‘Master Copy’ approved by the Quality Manager.

4.2 A ‘Control Copy’ of the SOP shall be distributed within the department and placed near related equipment or instruments as required.

 

5.0 ABBREVIATIONS

5.1 ABBREVIATIONS

5.1.1 SOP: Standard Operating Procedure
5.1.2 Lab: Laboratory

  

6.0 PROCEDURE

6.1 The laboratory log book is a bound data record book used for recording daily activities in the respective laboratory.

6.2 Laboratory record log books shall be issued to Analyst upon request.

6.3 Each page of the log book shall be pre-numbered by the assistant responsible for issuing it.

6.4 In case an incorrect entry is discovered, it shall be struck through with a single horizontal line.

6.5 All activities shall be recorded offline in the sequence they are completed.

6.6 The log book shall be maintained and preserved securely and confidentially; it shall not be taken outside the laboratory.

6.7 All dates shall be written in the format DD/MM/YYYY, where:

• DD: Date in numerical
• MM: Month in numerical
• YYYY: Year in numerical

 6.8   The complete log book shall be reviewed for technical adequacy and safely preserved in the archival area for future reference.

 

7.0 PRECAUTIONS

7.1 All entries shall be made in clear and simple language without ambiguity.

7.2 All entries and signatures must be legible.

7.3 Overwriting and the use of white correction fluid, black pens, or red pens are prohibited. Mistakes shall not be erased. Instead, draw a line through the error and record the correct information.

7.4 Related references shall be mentioned clearly as required.

 

8.0 REFERENCES

[List any applicable references here]

 

 

Standard Operating Procedure (SOP) for Handling, and Intermediate Checks of Certified Reference Materials (CRM)

  

1.0 PURPOSE

This Standard Operating Procedure (SOP) outlines the process for the procurement, handling, and intermediate checks of Certified Reference Materials (CRMs) used in chemical testing laboratories, specifically for the quantification of residues and metals in food and related products.

2.0 SCOPE

2.1 This SOP applies to all personnel involved in the handling and use of CRMs for chemical testing in food and related product laboratories.

3.0 RESPONSIBILITY

3.1 Analyst: Responsible for procuring, handling, maintaining, and performing intermediate checks of CRMs.

3.2 Quality Assurance (QA): Responsible for maintaining the SOP ‘Master Copy’ and ensuring that it is approved through the Quality Manager.

3.3 User Departments: Ensure that a 'Control Copy' of the SOP is available with the user department.

 

4.0 DISTRIBUTION

4.1 The QA department will ensure that the approved SOP is distributed to all relevant departments.

4.2 Each department should keep the ‘Control Copy’ for reference.

 

5.0 ABBREVIATIONS

• SOP: Standard Operating Procedure
• CRM: Certified Reference Material
• COA: Certificate of Analysis
• RPD: Relative Percent Difference
• ID: Identification
• R: Response
• WS: Working Standards
• NIST: National Institute of Standards and Technology

 

 

 

 

6.0 PROCEDURE

6.1 Procurement of Certified Reference Materials

6.1.1 CRMs must be procured from approved manufacturers or suppliers.

6.1.2 The procurement of CRMs should meet the following requirements:

• A current and valid Certificate of Analysis (COA) with traceability with ISO 17034.
• An expiration date that is current.
• NIST traceability should be ensured wherever possible during procurement.

6.2 Receipt of Certified Reference Materials

6.2.1 Upon receipt, each CRM shall be assigned a unique identification code for tracking, from the neat standard to the final dilution.
6.2.2 Documentation of the receipt should include the following details:

• Name of the CRM
• Unique identification code
• Purity
• Lot number
• Quantity received
• Gross weight
• Date received
• Expiration date

6.2.3 The receipt and traceability of each CRM must be documented and retained in the laboratory records.

6.3 Storage of Certified Reference Materials

6.3.1 CRMs should be stored at the temperature specified in the Certificate of Analysis (COA).

6.3.2 Stock standards and dilutions, including mixed standards, should be stored in refrigerators or freezers to prevent contamination or in the  specific condition if required.

6.3.3 Access to the storage areas should be controlled.
6.3.4 The following records must be maintained for storage:

• Temperature readings of refrigerators and freezers, recorded daily.
• Details of the standards used (e.g., standard name, volume, solvent, lot number, purity, final concentration, storage location).

6.3.5 CRMs should be used within 12 months of preparation or before expiration, whichever is earlier.

6.4 Preparation of Intermediate Dilutions

6.4.1 Intermediate dilutions, including mixed standards, should be prepared in a clean, controlled environment.
6.4.2 Each dilution should be labelled with the following information:

• Name of CRM
• Concentration
• Solvent used
• Date of preparation
• Initials of the preparer
• Expiration date

6.4.3 Documentation should include:

• Amount of stock standard used
• Solvent used
• Volume made up
• Date of preparation
• Final concentration
• Expiration date

6.5 Standard Intermediate Checking

6.5.1 Intermediate checks must be performed to ensure the integrity of dilutions and their concentrations.

6.5. Two working standards, labeled as WS1 and WS2, should be prepared separately. One standard (WS1) is made from the stock solution, and the other (WS2) is made from the intermediate dilution. Both standards should then be analyzed using the appropriate equipment to measure their respective responses (R1 for WS1 and R2 for WS2). These responses are used to check the consistency and accuracy of the standards.

6.5.3 The Relative Percent Difference (RPD) between the responses should be calculated as follows:

6.5.4 Acceptance Criteria: The RPD should not exceed 10%

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6.5.5 Any discrepancies should be investigated, and corrective actions should be taken.

6.6 Documentation of Intermediate Checks

6.6.1 All intermediate checks must be documented in the logbooks to ensure traceability and compliance with the SOP.

6.6.2 The logbook must include:

• Date and time of check
• Identification code of CRM used
• Responses obtained (R1 and R2)
• RPD calculation and results
• Any corrective actions taken, if applicable.

 

7.0 RECORDS

• Certificate of Analysis (COA) for each CRM
• Logbooks for intermediate checks and preparation of dilutions
• Temperature logs for storage units (refrigerators/freezers)
• Procurement records for each CRM

 

8.0 REVISION HISTORY

• Version 1.0 – As per the lab policy

$$$$

 

Standard Operating Procedure (SOP): Internal Calibration of Measuring Devices (Pipettes and Burettes)

1.      Purpose

To ensure the accuracy and reliability of measuring devices (pipettes and burettes) used in laboratory operations by calibrating them according to established procedures.

2.      Scope

This SOP applies to all pipettes and burettes used in the laboratory for volumetric measurements.

3.      Background

Measuring devices may have inherent or manufacturing errors. The accuracy of devices such as pipettes and burettes must be periodically verified and documented to ensure consistency and compliance with quality standards.

4.      Principle

The volume delivered by pipettes and burettes is determined by weighing the water dispensed and calculating the actual volume based on the density of water at the measured temperature.

 5. Materials Required

• Equipment:

Electronic balance (± 0.0001g precision)

Mono pan balance (1 kg capacity, ± 0.1g)

• Apparatus:

Clean 50 mL beaker

Graduated pipettes (10 mL, 5 pieces)

Bulb pipettes (10 mL, 5 pieces)

Volumetric flasks (100 mL and 250 mL, 5 pieces each)

• Consumables:

Distilled water (1 L)

Muslin cloth or blotting paper

• Reference:

Density chart for water at various temperatures

6. Procedure

6.1 Initial Preparations

1. Categorize the devices based on their stated capacity.
2. Record the temperature of the distilled water and note the corresponding density using the density chart.
3. Ensure all devices and containers are clean and dry.

6.2 Internal Calibration of Pipettes

1. Place a clean, dry 50 mL beaker on the electronic balance and tare it.
2. Using the first bulb pipette, dispense exactly 10 mL of distilled water into the beaker.
3. Record the weight of the water dispensed.
4. Empty and dry the beaker with muslin cloth or blotting paper.
5. Repeat steps 2-4 for the remaining bulb pipettes and graduated pipettes.
6. Record all observations in a tabular format.

6.3 Internal Calibration of Volumetric Flasks

1. Tare a dry 100 mL volumetric flask on the mono pan balance.
2. Fill the flask to the calibration mark with distilled water and weigh.
3. Record the weight of the water.
4. Repeat for all 100 mL and 250 mL volumetric flasks.
5. Record all observations.

7. Calculation

1.     Documentation

            Record observations in a tabular format: 

9. Results and Discussion

1. Express the error range for each category as % error ± 3×standard deviation.

Step by Step method for calculation

Step1

Step 2

Step 3

The standard deviation ($\sigma$) is 0.2586% in this case

Step 4

Step 5

2. Identify potential sources of errors, such as incorrect handling, environmental influences, or wear and tear.

 

10. Responsibilities

Lab Personnel: Perform internal calibration as per the SOP.

Lab Manager: Verify internal calibration records and ensure timely recalibration.

11. Review and Revision

SOP should be reviewed annually or whenever a change in procedure or equipment occurs.

Disclaimer:

This document is intended for guidance purposes only. Please refer to your laboratory's standard operating procedures and specific requirements to ensure compliance with applicable standards and regulations.

 

EU Regulation Update:2024/2777 Tritosulfuron (Pesticides)

In a recent regulatory update, the European Commission has decided not to renew the approval of tritosulfuron, a common pesticide active substance, under Commission Implementing Regulation (EU) 2024/2777. This move aligns with Regulation (EC) No 1107/2009 and impacts the availability and use of tritosulfuron-based products in EU agriculture.

Timeline for Implementation

• Entry into Force: 7 November 2024.
• Withdrawal of Authorisations: Member States must withdraw authorisations for tritosulfuron-based products within six months.

Maximum residue levels (MRLs) 

Existing maximum residue levels (MRLs) for tritosulfuron in the EU are already at the detection limit (0.01–0.05 mg/kg), so exporters can continue using tritosulfuron as long as residues meet these stringent limits.

COMMISSION IMPLEMENTING REGULATION (EU) 2024/2777

Commission Implementing Regulation (EU) 2024/2806

 

Commission Implementing Regulation (EU) 2024/2806 – Non-renewal of approval for metribuzin (Pesticide).

Metribuzin is no longer approved in the EU due to safety concerns raised by the European Food Safety Authority, including endocrine-disrupting risks and high bee toxicity. This will impacts Maximum Residue Limits (MRLs), for cassava, land cresses, and olives  likely to be reduced.

Timeline

• Effective Date: 24 November 2024
• Product Withdrawal: Within six months i.e 24 November 2025.
• MRL Revision: Expected by 2026.

The ban on metribuzin in the EU impacts food testing labs in several  ways:

1. Enhanced Residue Testing Requirements

Labs will need to conduct more sensitive tests to detect any trace levels of metribuzin in exports to the EU, as any residue could lead to shipment rejections. This may require advanced detection methods, especially for products with existing MRLs (like cassava, land cresses, and olives) until they are fully lowered or removed.

2. Upgraded Equipment and Protocols

With stricter regulations, labs may need to invest in more sensitive equipment or upgrade testing protocols to comply with EU standards. Ensuring equipment and methods can detect metribuzin at low levels of detection (LOD) is essential.

COMMISSION IMPLEMENTING REGULATION (EU) 2024/2806