TOC sampling verification is a process of evaluating the cleaning effect or whether the environment, samples, etc. meet relevant standards by collecting samples and testing the total organic carbon (TOC) content in cleaning verification and other scenarios. The following is a detailed introduction from the aspects of purpose, method, process, etc.:
Verification purpose 6

Ensure cleaning effect: In the pharmaceutical and food industries, production equipment needs to be cleaned after use. Through TOC sampling verification, it can be determined whether there are organic pollutants remaining on the surface of the equipment or in the cleaning fluid, confirm whether the cleaning procedure is effective, and whether the equipment can be cleaned to a level that meets production requirements to avoid residual substances from affecting the quality of subsequent products.

Ensure product quality and safety: Detect the TOC content of the environment or raw materials to prevent organic pollutants from exceeding the standard and introducing impurities, thereby ensuring the quality and safety of the final product and reducing the risks of product failure, deterioration, and harm to the health of users caused by pollution.
Meet regulatory and standard requirements: Relevant industry regulations and quality standards usually have strict regulations on production environment, equipment cleanliness, etc. TOC sampling verification is an important means for enterprises to meet regulatory compliance requirements and help enterprises pass inspections and audits by regulatory agencies.

Sampling method
Cotton swab wiping method: suitable for equipment that is easy to wipe and has a flat surface. Use a special TOC cleaning verification cotton swab to wipe the specified sampling area with a certain force and method (such as a straight line, S-shaped or spiral path) to adsorb the residual organic matter on the surface of the equipment onto the cotton swab, and then put the cotton swab into a specific sample bottle.
Eluent method: For equipment and pipelines that are not easy to wipe for sampling, the elution method is used. Rinse the equipment or pipeline with a certain amount of eluent (such as purified water, etc.), collect the eluent as a sample, and use it to determine the TOC content in it to infer the cleanliness of the internal surface of the equipment.

Verification process 1
Preparation stage: Personnel need to wear appropriate clean clothes, gloves and other personal protective equipment. Prepare sterile cotton swabs, TOC vials, markers, sampling labels and other tools and consumables that have a low TOC blank background and are suitable for TOC detection. According to the cleaning validation plan, determine the sampling area, number and location of sampling points. Usually, select the parts of the equipment surface that are difficult to clean and easy to accumulate residues.

Sampling operation: If the cotton swab wiping method is used, first use disposable dust-free paper or special cleaning cloth to perform preliminary cleaning near the sampling point to avoid cross contamination. Then use injection water to moisten the cotton swab head to ensure that the cotton swab is fully moistened but not excessively dripped, and then wipe the wet cotton swab evenly at the specified strength and speed to ensure that the entire sampling area is covered. If the elution method is used, the target part is eluted with the eluent in the specified amount and method, and the eluent is collected.

Sample processing and storage: If the same sampling point needs to be wiped multiple times, it may be necessary to gently stir and mix all the wiping cotton swabs in the container to obtain a representative sample. Immediately close the sampling container to ensure its sealing to prevent sample evaporation or contamination. If the sample needs to be sent for inspection within a certain period of time, it should be stored according to the conditions specified in the validation plan (such as refrigeration temperature) and sent to the laboratory for TOC analysis as soon as possible.

Laboratory analysis: According to the laboratory method, the sample may need to be filtered, diluted, extracted and other pre-treatment steps to meet the requirements of the TOC analyzer. Use a validated TOC analysis method to measure, record and calculate the TOC content of each sample. Compare the measurement results with the set cleaning limits to evaluate whether the cleaning effect meets the requirements.

What is TOC Verification Sampling Application areas
Pharmaceutical industry: used for production equipment cleaning verification, clean room environment monitoring, quality control of raw materials and packaging materials, etc., to ensure the sterility and pollution-free of the drug production process and ensure the quality of the drug.
Food and beverage industry: Cleaning verification of production equipment and processing environment, detection of the sanitary conditions of food contact surfaces, and quality inspection of raw materials, packaging materials, etc., to prevent organic contamination and ensure food safety.

Electronics industry: In the process of semiconductor manufacturing and electronic component production, TOC sampling verification is performed on production equipment, ultra-clean workshop environment, etc. to control organic pollutants and avoid affecting the performance of electronic products.
Water treatment industry: Monitor the TOC content in drinking water, industrial water, wastewater and other water bodies, evaluate water quality, and provide a basis for evaluating and optimizing the effect of water treatment processes.

huachenyang offers the following cleaning validation swabs:

iclean®Polyester Knit Series -CY-714K, CY-761K – suitable for use in TOC analysis
iclean®Polyester Knit Series – CY-715 – suitable for HPLC analysis using a UV detector analytical method
ICLEAN® Polyester Non-Woven Large Swab -CY-716 – suitable for HPLC analysis

cleaning validation cleanroom swabs are used to determine the effectiveness of cleaning protocols as specified by the US FDA. HPLC/ UV-Vis Total Organic Carbon (TOC) analysis are different methods used to validate these cleaning processes.

Benefits

All Cleaning Validation swabs are precision-manufactured and constructed to exacting and consistent tolerances without the use of adhesives for superior performance
Notched, rigid 100% polypropylene, break-away handle allows the head to be placed into the vial with minimal handling and contamination and provides excellent chemical resistance
Lot coded for traceability and quality control
CY-714K, CY-761K: Certified Low TOC level (<50 μg/L, <50 ppb) ensures consistency in swab background contribution
Double layered, double knit polyester head entraps contaminants in the knit structure during sampling, allowing maximum contaminant collection and release into the diluent to provide for excellent recovery rates
CY-715: This swab is additionally processed to reduce the UV background. Proprietary cleaning process reduces interference in the 230 nm range, resulting in an improved limit of detection

Part Number: CY-714K

Product Specs

Inner Bags: 20 swabs/bagOuter Bags: 50 bags/casePackaging: 1,000 swabs total/case

MADE IN CHINA

Swabbing is the preferred method to validate critical cleaning within pharmaceutical manufacturing environments. The 1993 FDA Guide to Inspections states that direct surface sampling (e.g., with swabs) is the “most desirable” technique. Potential contaminants eluted from the swab are tested down to trace levels. As a result, the selection of a quality swab and a validated swabbing method is critical to producing sensitive, accurate, and repeatable results.

The purpose of swabbing is to prove that the cleaning process served its purpose. The cleaning process must successfully remove any active pharmaceutical ingredients (API) used in previous batch runs while not leaving any residues behind from the cleaner itself.

Measurement of the Residual Acceptable Limit (RAL) can be accomplished with High Performance Liquid Chromatography (HPLC) or Total Organic Carbon (TOC) tests. HPLC-UV is a specific analysis technique that identifies and quantifies the residues found within the sample. TOC is a non-specific conductometric assay that is a catch-all for quantifying oxidizable carbon compounds within the sample.

Cleaning validation employing
These analytical methods is a complex activity requiring a careful selection of the procedure and materials involved. Establishing a capable method begins with the selection of the swab. The swab must offer:

Minimal extractable interferences
Ultra-low particles and fibers
Solvent compatibility
High recovery rates

Huachenyang’s Cleaning Validation Swabs

CY-761

CY-715A

are engineered to meet this demand. As an example, the CY715 swab offers a low absorbance spectrum in the 190-235 nm range for HPLC analysis. This range is significant as it is the detection range typical of common residues. Swabs with a high UV absorbance background in this range interfere with the result by concealing residue contamination.

TOC measurements are extremely sensitive. They are reported in part per billion (ppb) (equivalent to micrograms per liter (µg/L)). Any particles from the swab head material or sample container can contribute to the TOC value. The lower the contribution and variance of these particles, the less interference from this TOC background.

Huachenyang offers TOC kits with swabs and vials specifically manufactured to low TOC tolerances. Low TOC swabs within the CY3340 and CY3342 kits are certified to <50 ppb TOC while their vials are treated to ensure a <10 ppb TOC background. The swabs are pre-scored with notches to allow the head to break off easily and cleanly. The swab head can be snapped off by aligning its handle on edge, with the notch placed on the top edge of the vial and pulling down to snap the handle. This method eliminates the use of scissors, thereby eliminating an action that could contribute to more particulates (i.e., a higher TOC background).

In addition to having minimal analytical interferences, high quality cleaning validation swabs must allow for high recovery rates. Recovery rates are a function of swabbing method as well as material absorption and residue-releasing of the swab.

The swabbing pattern used is critical to ensure an accurate and reproducible collection of residues.
The first side of the first swab is swiped horizontally ten times.
The swab head is flipped over and the second side is swiped vertically ten times over the same surface.
The swab is deposited in the vial.
The first side of the second swab is swiped diagonally upwards ten times.
The swab is flipped over and the second side is swiped diagonally downward ten times.
The second swab head is deposited in the vial.

Huachenyang’s Cleaning Validation Series swabs all use polyester fibers in their head material which offers a wide solvent compatibility. This compatibility is essential for recovering the residue off the surface and depositing it into the preselected diluent for testing.