METHOD DEVELOPMENT FOR DETERMINATION OF ALUMINIUM IN BAKSO FOOD PRODUCTS USING VISIBLE SPECTROPHOTOMETRY

• Main Author: Rochmahdian, Fitri
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/40126
• Institution: Institut Teknologi Bandung

Since aluminium is a toxic metal and aluminium compound is suspected still to be illegally added into food product, analytical method for determination of aluminium in this food products is needed. Commonly, quantitative analysis of aluminium is based on spectroscopic methods such as Atomic Absorption Spectroscopy (AAS) and Induced Coupled Plasma (ICP). However, these instruments are not always available in any testing laboratories and hence alternative method executable applying simpler equipment is needed. The aim of this research was to obtain an analytical method for determination of aluminium in food using visible spectrophotometry as an alternative method. Aluminium was reacted with Alizarin Red S to form colored complex compound measurable in the visible light region. The optimum pH for the complex formation was around 5 with a maximum absorption wavelength of 494 nm. The calibration curve in the concentration range of 4-14 ppm showed good linearity with the equation of y = 0.0295x + 0.3287 and the correlation coefficient (r) of 0.99. Absorbance of the complex measured at 494 nm was stable up to 70 minutes. Furthermore complex formation under the influence of disturbing metal cations such as Pb 2+ , Cu 2+ , Fe 2+ , Fe 3+ , and Zn 2+ was observed. Prior measurement, food samples need to be prepared by ashing method. The precision of the method is calculated as relative standard deviation (RSD) of intra- and inter- days with the values of 2.11 and 2.31% respectively, while accuracy calculated as percent recovery at concentrations of 40, 50, and 60 ppm were 82.07, 84.87, and 93.88%. Limits of detection (LOD) and limits of quantification (LOQ) calculated statistically were 2.04 and 3.74 ppm, respectively. Based on the overall results, it can be concluded that the method developed can be used as an alternative method for determination of aluminum in food samples.