纳米铜/低密度聚乙烯复合膜中铜向食品模拟物迁移量的测定

Determination of the migration of copper from nanocopper/low density polyethylene composite film in food simulants

建立了电感耦合等离子体发射光谱法(inductively coupled plasma optical emission spectrometry,ICP-OES)和石墨炉原子吸收光谱法(graphite furnace atomic absorption spectrometry,GFAAS)对纳米铜/低密度聚乙烯(low density polyethylene,LDPE)中铜向食品模拟物迁移量的检测方法。将纳米铜和经3-氨丙基三乙氧基硅烷((3-Aminopropyl)triethoxysilane,KH550)处理的纳米铜分别添加到LDPE母粒中制备成纳米铜/LDPE复合膜。在40℃下,将纳米铜/LDPE复合膜在3%乙酸和10%乙醇2种食品模拟物中浸泡10 d,以ICP-OES测定3%乙酸中铜的含量,以GFAAS测定10%乙醇中铜的含量。结果表明:2种模拟物中,铜分别在0.02~0.5μg/m L和2.5~25μg/L范围内线性良好,R^2大于0.999,回收率分别在81.42%~100.22%和81.71%~96.05%,RSD分别为1.02%~8.87%和1.66%~8.24%(n=6),检出限为0.90μg/L和0.20μg/L,定量限为3.10μg/L和0.68μg/L,表明这2种方法精密度好,灵敏度高,定性定量准确。

Methods were developed for determination of the migration of copper from nanocopper/low density po- lyethylene （nanoeopper/LDPE） composite films into food simulants by inductively coupled plasma optical emission spectrometry （ICP-OES） or graphite furnace atomic absorption spectrometry （GFAAS）. Nanocopper and modified nanocopper by （3-Aminopropyl） triethoxysilane （KH550） were mixed with LDPE granules, new granules containing nanocopper and modified nanocopper were added into the composite films by a film-blowing machine. The films were exposure to 3% acetic acid and 10% ethanol at 40 ℃ for 10 days, the migration of copper in 3% acetic acid and 10% ethanol were determined by ICP-OES and GFAAS respectively. For both food simulants, the results showed the calibration curves of copper were linear in the range of 0.02 - 0.50 μg/mL and 2.50 - 25.00 μg/L with correlation coefficients not less than 0. 999. The spiked recoveries at different spiked levels were in the range of 81.42%- 100.22% and 81.71%-96.05% with relative standard deviation （RSD） of 1.02% -8.87% and 1.66% -8.24% , respectively. The limit of detection were 0.90 μg/L and 0.20 μg/L and the limit of quantitation were 3.10 μg/L and 0.68 μg/L, respectively. The results indicated that both methods were precise, highly sensitive and accurate.