天然橡胶、异戊橡胶和天然橡胶/异戊橡胶并用胶的鉴定方法

Identification method of natural rubber,isoprene rubber and natural rubber/isoprene rubber blend

以丙酮为溶剂,对6种天然橡胶和2种异戊橡胶进行抽提,基于天然橡胶与异戊橡胶丙酮抽提浓缩液成分存在差异,选择了天然橡胶生胶、异戊橡胶生胶、天然橡胶硫化胶、异戊橡胶硫化胶和天然橡胶/异戊橡胶并用硫化胶定量分析内标物,此外还采用内标法对丙酮抽提浓缩液进行分析,从而建立了天然橡胶、异戊橡胶及天然橡胶/异戊橡胶并用胶的鉴定方法,最后将该方法应用于送检样品主体成分的鉴定。结果表明,角鲨烷可作为天然橡胶、异戊橡胶和天然橡胶/异戊橡胶并用胶定量分析的内标物;在优选的气相色谱-质谱联用定量分析检测条件下,通过定性分析天然橡胶中的γ-谷甾醇和γ-生育三烯酚,同时结合内标法定量分析硫化胶丙酮抽提浓缩液中特定抗氧剂的含量,可以测定天然橡胶/异戊橡胶并用胶中天然橡胶和异戊橡胶的并用比,其中以质荷比为296的特征碎片离子作为异戊橡胶SKI-3定量分析参照特征碎片离子的偏差为-5%;该鉴定方法对于送检样品主体成分的鉴定结果较好。

Six kinds of natural rubbers and two kinds of isoprene rubbers were extracted with acetone as the solvent,and the selection of the internal standard for quantitative analysis of raw rubbers of natural rubber and isoprene rubber and vulcanizates of natural rubber,isoprene rubber and natural rubber/isoprene rubber blend was based on the diffe-rence in the composition of acetone extract concentrate of natural rubber and isoprene rubber.In addition,acetone extract concentrate was analyzed by internal standard method,and the identification method of natural rubber,isoprene rubber and natural rubber/isoprene rubber blend was established.Finally,the method was applied to the identification of the main components of the submitted samples.The results showed that squalane could be used as the internal standard for quantitative analysis of natural rubber,isoprene rubber and natural rubber/isoprene rubber blend.Under the preferred gas chromatography-mass spectrometry quantitative analysis and detection conditions,the blending ratio of natural rubber and isoprene rubber in natural rubber/isoprene rubber blend could be measured by the qualitative analysis ofγ-sitosterol andγ-tocotrienol in natural rubber,combined simultaneously with the quantitative analysis of the specific antioxidant in the acetone extract concentrate of vulcanizate by internal standard method,of which the deviation was-5%when the characteristic fragment ion whose mass to charge ratio was 296 was used as the referenced characteristic fragment ion for quantitative analysis.The identification method showed good results in identifying the main components of the submitted samples.