ABSTRACT
An inter-laboratory study involving 24 laboratories was conducted to validate the modified analytical method for the migration solution of heptane for the determination of bisphenol A migrating from polycarbonate food processing materials. In this study, two concentrations of samples were blindly coded. Each laboratory determined the analyte (bisphenol A, phenol and p-tert-butylphenol) concentration in each sample according to the established protocol. The obtained values were analyzed statistically using internationally accepted guidelines. Horwitz ratios were calculated based on the reproducibility relative standard deviation (RSDR), which was estimated from the inter-laboratory study, and predicted RSDR, which was calculated using the Horwitz/Thompson equation. Horwitz ratios of the two samples ranged from 0.15 to 0.37 for the three compounds, meeting the performance criteria of less than 2 set by the Codex Alimentarius for analytical method approval. These results showed that this modified analytical method shows good performance as an analytical method for the migration solution of heptane.
Subject(s)
Heptanes , Phenols , Reproducibility of ResultsABSTRACT
A validation study was performed on the modified analytical method for the migration solution of heptane, 20% ethanol and 4% acetic acid for the determination of bisphenol A migrating from polycarbonate food apparatuses, containers, and packaging. The analytes for the method were bisphenol A, phenol and p-tert-butylphenol. The repeatability, within-laboratory reproducibility and trueness of the method was estimated in the range of 0.2-1.8%, 0.4-2.6% and 95-102% respectively. These results showed that the method is useful as an analytical method for the migration solution of heptane, 20% ethanol and 4% acetic acid. Furthermore, the applicability of the determination methods with a fluorescence detector was verified. As a result of the validation study, the repeatability, within-laboratory reproducibility and trueness of the method was estimated in the range of 0.1-2.9%, 0.2-3.1% and 94-101% respectively. It was confirmed that the measurement with a fluorescence detector is also available.
Subject(s)
Acetic Acid , Phenols , Reproducibility of Results , Ethanol , HeptanesABSTRACT
We compared test methods for measurement of lead in metal utensils using flame-atomic absorption spectroscopy (AAS), graphite furnace-AAS (GFAA), inductively coupled plasma atomic emission spectrometry (ICP) and X-ray fluorescence analysis (XRF). The procedure for preparation of the test solution was improved. A 100 mg of sample was dissolved in 2.5 mL of HCl and HNO(3) (3 : 1) mixture (in the case of titanium sample, dissolved in HCl). Stock solution was prepared by diluting to 50 mL with water. The test solution was prepared by diluting with 0.1 mol/L HNO(3). The recoveries of lead added to various kinds of metal reagent at the level of 0.1% were 90-118%. When standard materials which contained lead at the level of 0.0098-0.11% were measured, the measured values were in close agreement with the standard values. These procedures are applicable to aluminum, iron, stainless steel, copper, tin and titanium products. The AAS method, GFAA method and ICP method were suitable as the lead test methods. Moreover, the XRF method was useful as a screening method or a simple determination method. The ICP method was used to determine the lead contents in 22 kinds of commercial metal utensils, and 0.011-0.040% of lead were detected in 6 samples.
