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.
两种取样技术通常用于清洁验证：淋洗测试和擦拭测试。以下是棉签检测可能出现的问题。
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.
一般来说，使用棉签检测化学或微生物残留物是可能的。通常，与用于微生物表面采样的琼脂板相比，微生物拭子的回收率较低，下面只讨论用于检测化学残留物（产品或洗涤剂残留物）的拭子。
Critical steps during swab testing 擦拭取样的关键步骤
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:
擦拭取样过程本身，除了分析之外（这里不讨论），还有两个关键步骤必须优化，考虑到表面材料和残留物：
Step 1: Picking up the residues from the surface in contact with the product using the material ofthe "swab head".
第1步：用“拭子头”将与产品接触的表面的残留物捡起。
Step 2: Transfer of the residues from the material of the "swab head" into the extraction solution.
第2步：将“拭子头”材料中的残留物转移到提取液中。
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.
除了可再生的棉签技术外，棉签的材料本身也是至关重要的。使用棉质棉签不再是“最先进的技术”。它们本身会在产品接触表面释放颗粒，根据拭子技术不同，在拭子过程中可能会分解，或者不能将残留物释放到提取溶液中。现代棉签有一种研磨材料，除了使用湿润的棉签头溶解残留物外，还可以机械地将其从表面清除。在这种情况下，正确的压力是很重要的，压力可以通过棉签显示出轻微的弯曲来确认。一般来说，在正确的压力下在矩形取样面取样是可取的。为了确保正确的采样区域，建议在重叠的路径上进行棉签采样，并至少对指定的表面区域进行采样。
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.
更大的擦拭表面积意味着“最坏情况”，并确保由于较小的擦拭表面积而产生错误的低结果。擦拭后，擦拭的表面应尽可能少地保留用于擦洗头预润湿的提取液。在特殊情况下，用第二根干棉签再次擦拭表面可能是有用的。此外，应注意的是，在用暖或热介质清洗过程或干燥步骤后，设备表面需要冷却到室温。
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.
根据擦拭技术，残留物的转移在步骤2中依次进行。在这里，棉签在每个棉签步骤之间的萃取溶液中旋转。采样后，棉签通常被转移到提取溶液中，并留在那里直到分析检测。在此之前，可以使用振动筛或超声波浴来实现额外的增强萃取。通过优化萃取溶液可以提高取样回收率。这主要取决于残渣的类型和条件。然而，萃取液本身也应该易于清洁，而且不会干扰分析。
