Two sampling techniques are generally used in cleaning validation: the rinse test and the swab test. The following are notes on potential issues with the swab test.
兩種取樣技術通常用于清潔驗證：淋洗測試和擦拭測試。以下是棉簽檢測可能出現的問題。
In general, the use of swabs for the detection of chemical or microbiological residues is possible. Usually, the recovery of microbiology swabs is lower compared to agar plates for microbial surface sampling, only the swab for the detection of chemical residues (product or detergent residues) is addressed in the following.
一般來說，使用棉簽檢測化學或微生物殘留物是可能的。通常，與用于微生物表面采樣的瓊脂板相比，微生物拭子的回收率較低，下面只討論用于檢測化學殘留物（產品或洗滌劑殘留物）的拭子。
Critical steps during swab testing 擦拭取樣的關鍵步驟
The swab sampling process itself, in addition to the analysis, which will not be discussed here, has two critical steps that must be optimized considering surface materials and residues:
擦拭取樣過程本身，除了分析之外（這里不討論），還有兩個關鍵步驟必須優化，考慮到表面材料和殘留物：
Step 1: Picking up the residues from the surface in contact with the product using the material ofthe "swab head".
第1步：用“拭子頭”將與產品接觸的表面的殘留物撿起。
Step 2: Transfer of the residues from the material of the "swab head" into the extraction solution.
第2步：將“拭子頭”材料中的殘留物轉移到提取液中。
In addition to a reproducible swab technique, the material of the swab itself is crucial. Using cotton made swabs is no longer "state of the art". These can themselves release particulates on the product contact surface, disintegrate during the swab process depending on the swab technique, or fail to release the residues into the extraction solution. Modern swabs have an abrasive material which, in addition to dissolving the residues by using a moistened swab head, also removes them mechanically from the surface. In this case, the correct pressure, which can be checked if the swab shows a slight bending, is important. In general, rectangular sampling surfaces sampled in a check pattern are preferable. To ensure a correct sampling area, it is advisable to swab in overlapping lanes and sample at least the specified surface area.
除了可再生的棉簽技術外，棉簽的材料本身也是至關重要的。使用棉質棉簽不再是“最先進的技術”。它們本身會在產品接觸表面釋放顆粒，根據拭子技術不同，在拭子過程中可能會分解，或者不能將殘留物釋放到提取溶液中。現代棉簽有一種研磨材料，除了使用濕潤的棉簽頭溶解殘留物外，還可以機械地將其從表面清除。在這種情況下，正確的壓力是很重要的，壓力可以通過棉簽顯示出輕微的彎曲來確認。一般來說，在正確的壓力下在矩形取樣面取樣是可取的。為了確保正確的采樣區域，建議在重疊的路徑上進行棉簽采樣，并至少對指定的表面區域進行采樣。
More surface area swabbed means a "worst-case" and ensures that a falsely low result is generated due to a smaller surface area swabed. After swabbing, as little extraction solution, which is used for pre-moistioning the swab head, as possible should remain on the surface. In special cases it may be useful to swab the surface again with a second dry swab. In addition, it should be noted that after cleaning processes with warm or hot media or a drying step, the equipment surface needs to cool down to room temperature.
更大的擦拭表面積意味著“最壞情況”，并確保由于較小的擦拭表面積而產生錯誤的低結果。擦拭后，擦拭的表面應盡可能少地保留用于擦洗頭預潤濕的提取液。在特殊情況下，用第二根干棉簽再次擦拭表面可能是有用的。此外，應注意的是，在用暖或熱介質清洗過程或干燥步驟后，設備表面需要冷卻到室溫。
Depending on the swab technique, the transfer of the residues is carried out sequentially in step 2. Here, the swab is swirled in the extraction solution between the individual swab steps. After sampling, the swab is typically transferred into the extraction solution and left there until analysis. Prior to this, additional enhanced extraction can be achieved using a vibratory shaker or an ultrasonic bath. Sampling recovery can be improved by optimizing the extraction solution. This mainly depends on the type and condition of the residue. However, the extraction solution itself should also be easily cleanable and furthermore not interfere with the analysis.
根據擦拭技術，殘留物的轉移在步驟2中依次進行。在這里，棉簽在每個棉簽步驟之間的萃取溶液中旋轉。采樣后，棉簽通常被轉移到提取溶液中，并留在那里直到分析檢測。在此之前，可以使用振動篩或超聲波浴來實現額外的增強萃取。通過優化萃取溶液可以提高取樣回收率。這主要取決于殘渣的類型和條件。然而，萃取液本身也應該易于清潔，而且不會干擾分析。
