双波长瑞利光散射技术测定食品中的Cu

Determination of Cu in Food by Dual-Wavelength Rayleigh Light Scattering Technique

建立快速、准确、高灵敏测定Cu(Ⅱ)的双波长-瑞利光散射(dual-wavelength Rayleigh light scattering,DWO-RLS)法,研究RLS光谱特征、适宜反应条件及共存物质的影响。在最大RLS波长528 nm和次大RLS波长361 nm处,Cu(Ⅱ)的质量浓度在0.003~0.21 mg/L范围内与体系的RLS猝灭程度(ΔI_(RLS))呈良好的线性关系,检出限为9.81 ng/mL(RLS,361 nm)、8.62 ng/mL(RLS,528 nm)和4.61 ng/mL(DWO-RLS,361 nm+528 nm),定量限分别为0.16 mg/100 g(361 nm)、0.14 mg/100 g(528 nm)和0.077 mg/100 g(361 nm+528 nm)。方法可用于多种食品中Cu的快速测定。

A rapid, accurate, highly sensitive dual-wavelength Rayleigh light scattering method for quantifying Cu（Ⅱ） was established. The Rayleigh light scattering spectral characteristics, the appropriate reaction conditions and the influence of coexisting substances were studied. At the maximum Rayleigh scattering wavelength of 528 nm and the second major Rayleigh scattering wavelength of 361 nm, the mass concentration of Cu（Ⅱ） in the range of 0.003 to 0.21 mg/L was directly proportional to the Rayleigh light scattering quenching degree（ΔIRLS）of the system. The limits of detection（LOD） were 9.81 ng/mL（RLS, 361 nm）, 8.62 ng/mL（RLS, 528 nm） and 4.61 ng/mL（DWO-RLS, 361 nm ＋ 528 nm）, and the limits of quantitation（LOQ） were 0.16 mg/100 g（361 nm）, 0.14 mg/100 g（528 nm） and 0.077 mg/100 g（361 nm ＋ 528 nm）, respectively. The method can be used for the rapid determination of copper in various foods.