6.1.3Swab and Wipe Sampling 擦拭取样法 Bothswab sampling and wipe sampling involve wiping a surface with a fibrousmaterial (most commonly). During the wiping procedure, the residue on thesurface may be transferred to the fibrous material. The fibrous material isthen placed in a solvent to transfer the residue to the solvent. The solvent isthen analyzed for the residue by an appropriate and validated analyticalmethod. For swabs, the fibrous material is some kind of textile (knitted, wovenor nonwoven) attached to a plastic handle.Wipes are fibrous materials, usuallywoven or non-woven textiles, which are applied to the sampled surface by hand.A special case of swabs is the use of cotton balls or pads, which are movedacross a surface with forceps. The selection of swab or wipes to be usedrequires an evaluation of the swab properties, such as extractables andshedding properties. Recovery of residues from surfaces also depends on thesize and shape of the swab head or wipe, as well as the properties (such asflexibility and length) of the swab handle. 拭子以及擦拭取样都采用纤维材料(最常用)擦拭表面。擦拭过程中,表面的残留物会被转移到纤维材料上。然后再将纤维材料置于溶剂中,将残留物转移到溶剂中去。然后用经过验证的合适方法分析溶剂中的残留物。拭子的纤维材料是一种带有塑料把手的纺织物(针织、机织或无纺布)。擦拭巾是机织或无纺布类的纤维材料,用来手工对表面进行取样。用钳子钳住进行表面擦拭的棉球或棉垫是一种特殊类型的拭子。选择拭子或擦拭巾前需要评估拭子性质,如析出物和脱落物。表面残留物的回收率还取决于拭子头部或擦拭巾的大小和形状以及把手的性质(例如弹性和长度)。
Inmost cases, the swabs and wipes are wetted with a solvent prior to sampling thesurface. The solvent selected should be able to assist in dissolving theresidue and also be compatible with the analytical method. For example, forHPLC analysis, the solvent could be mobile phase. For TOC and conductivity, thesolvent is almost always water. For sampling the same site, companies maychoose to sample the same surface area with multiple swabs or wipes in order toprovide a higher percent recovery of residue from the surface. In such cases,the additional swab(s) or wipe(s) utilized may be either dry or wetted with thesame solvent. 大多数情况下,表面取样前要用溶剂润湿拭子以及擦拭巾。选择的的溶剂应有助于溶解残留物并同分析方法兼容。例如,对于高效液相色谱分析,溶剂应当选择流动相。对于有机碳和电导率分析,溶剂一般选择水。为了得到更高的表面残留物回收率,公司一般选择采用多个拭子或擦拭巾对同一表面进行取样。在这种情况下,其他的拭子或擦拭巾可以是干燥的或用同一溶剂润湿。
Wipesare typically larger pieces of textile material, and may be used to samplelarger equipment areas. 擦拭巾通常是大块的纺织材料,适用于设备较大表面的取样。
Theswab or wipe that has been applied to the surface is then extracted with asuitable solvent to remove the analyte from the swab into the extractionsolvent for analysis (see Table 6.1.3-1 for advantagesand limitations).The extraction solvent may be the same or different solvent as that used for wettingthe swab. 用合适的溶剂萃取表面取样后的拭子和擦拭巾,将被测物从拭子转移至提取溶液中进行检测(参见表6.1.3-1优点和局限性)。提取溶剂可以和润湿拭子的溶剂相同或不同。
Table6.1.3-1 Advantages and Limitations of Swab/Wipe Sampling 表6.1.3-1 擦拭取样的优点和局限性
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