Data for: Development of a rapid micro-Raman spectroscopy approach for detection of NIAS in LDPE pellets and extruded films for food packaging applications

Identification and quantification of Non Intentionally Added Substances (NIAS) at low concentrations and eventually their distribution on Low Density Polyethylene (LDPE) films is an important issue. As Raman spectroscopy techniques are innovative and sensitive analytical methods and do not require pretreatment and manipulation of the sample, these were used for the identification of NIAS in LDPE pellet and films, which are commonly used for food packaging applications. The aggregation state of NIAS in LDPE were observed by Raman imaging with micrometric resolution. Four main NIAS compounds were identified in granule and film surfaces by confocal Raman spectroscopy: calcite (CaCO3), calcium sulphate (CaSO4), polystyrene (PS) and titanium dioxide (TiO2) in anatase form. By a semi-quantitative evaluation of the inorganic NIAS, 9.93 mg/kg of CaCO3, 1.62 mg/kg of CaSO4 and 0.17 mg/kg of TiO2 were estimated. The experimental findings achieved by Raman analysis were confirmed by the results obtained by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Moreover, the toxicity of the identified compounds was examined according to the Cramer rules.针对低密度聚乙烯（Low Density Polyethylene, LDPE）薄膜表面低浓度非有意添加物质（Non Intentionally Added Substances, NIAS）的识别、定量及其分布特征分析是一项重要研究课题。拉曼光谱技术作为一种创新性、高灵敏度的分析方法，无需对样品进行预处理与操作，因此被用于食品包装常用的LDPE颗粒与薄膜中的NIAS识别。借助微米级分辨率的拉曼成像技术，可观测LDPE基质中NIAS的聚集状态。通过共聚焦拉曼光谱，在颗粒与薄膜表面共识别出四种主要NIAS化合物：方解石（CaCO₃）、硫酸钙（CaSO₄）、聚苯乙烯（Polystyrene, PS）以及锐钛矿相二氧化钛（Titanium Dioxide, TiO₂）。通过对无机NIAS的半定量评估，估算得到CaCO₃含量为9.93 mg/kg、CaSO₄含量为1.62 mg/kg，TiO₂含量为0.17 mg/kg。拉曼分析得到的实验结果，通过电感耦合等离子体质谱法（Inductively Coupled Plasma-Mass Spectrometry, ICP-MS）的测试结果得到了验证。此外，依据克莱默规则（Cramer rules）对所识别化合物的毒性进行了考察。