ISO 20418-1:2018规定了一种定性和定量测试方法，通过显微镜初步筛选、蛋白质提取、酶消化和使用配备电喷雾电离源（LCI-ESI-MC）的液相色谱-质谱仪检测特定肽，测定纺织品中羊毛、羊绒、牦牛纤维及其混合物的含量。 该方法可适用于各个工艺阶段（即从原材料到服装）的相关纺织产品，且成分分布均匀。它可用于含有羊毛、羊绒或牦牛纤维及其混合物的不同类型的纺织材料（例如，主食、上衣、纱线和织物）。该方法基于通过光学显微镜对混合物中所有纤维的形态进行初步鉴定。 然后用硫脲/尿素/二硫苏糖醇（DTT）溶液提取蛋白质。用胰蛋白酶对从纤维中提取的蛋白质进行酶消化。通过LC-MS对特定标记物进行分析，并计算百分含量。 通过将其结果与使用ISO 1833系列和/或ISO 17751系列获得的结果相结合，该方法适用于含有羊毛、羊绒和牦牛以外其他种类纤维的样品。 如果存在相同动物种类的纤维（例如羊绒和马海毛的混合物），ISO 20418-1:2018不适用；在这种情况下，可以使用显微镜分析（例如ISO 17751系列）进行定量分析。

ISO 20418-1:2018 specifies a qualitative and quantitative testing method to determine the content of wool, cashmere, yak fibres and their blends in textiles by microscope preliminary screening, protein extraction, enzymatic digestion and specific peptides detection using a liquid chromatography-mass spectrometer equipped with electrospray ionization source (LCI-ESI-MC). This method can be applied to relevant textile products at each process stage (i.e. from raw material to garment) with a homogeneous distribution of the components. It can be applied to different types of textile materials (e.g. staples, tops, yarns and fabrics) that contain wool, cashmere or yak fibres and their blends. The method is based on a preliminary identification of all fibres in the blend on the basis of their morphology, by light microscopy. The proteins are then extracted by a thiourea/urea/dithiothreitol (DTT) solution. An enzymatic digestion by trypsin of the protein extracted from the fibres is carried out. Analysis of the specific markers is performed by LC-MS and the percent composition is calculated. This method is applicable to samples containing other kinds of fibres than wool, cashmere and yak, by combining its results with the results obtained using the ISO 1833 series and/or the ISO 17751 series. ISO 20418-1:2018 does not apply if fibres of the same animal species are present (e.g. blends of cashmere and mohair); in this case, the quantitative analysis can be performed using microscopic analysis (e.g. ISO 17751 series).