David J. Alcarde Jr., Elyson Keith P. Encarnacion, Anne C. Alcantara, Harold E. Armario, Winnie P. Alejandro, Agaseve F. Del Rosario, Rizel Marie S.M. Ting, Ellaine R. Dioso
Kinetic Modeling of Chemical Migration from Polyethylene Packaging Film: A Comparative Study of Regulatory Methods

An awareness of chemical migration kinetics from the packaging to food is critical to determine consumer exposure and measure regulatory compliance. This paper analyzes the migration kinetics of the chemical residues of monolayer low density polyethylene (LDPE) package films under US 21 CFR and JETRO 2009 guidelines. LDPE film specimens were extracted with n-heptane at 21 °C for 30 minutes (US CFR) and 25 °C for 60 minutes (JETRO 2009). Migration data were modeled with zero-, first-, and second-order kinetic models. The results indicated poor correlation (R² < 0.1) for all the models, with second-order kinetics providing marginally better fits for low-concentration samples. High-concentration samples showed high variability, revealing complicated migration mechanisms outside classical kinetics. Residual analysis indicated uniform underprediction by zero- and first-order models. Generally, none of the conventional kinetic models sufficiently described migration behavior, which indicated shortcomings of traditional modeling strategies and the need for more appropriate modeling strategies in food safety evaluation.

Nathalie Guigues, Sandrine Raveau, Jérémie Majar, Gaëlle Canteau, Béatrice Lalere
Comparing EN 17075 and VaMPIS approaches for in situ continuous monitoring of free chlorine in drinking water

The performances of commercially available on-line analysers for monitoring free chlorine in water was carried out following protocols described in EN 17075 standard. Measurement uncertainty was estimated under controlled conditions considering bias, repeatability, and deviation from linearity as well as key influential factors for amperometric chlorine measurement: pH and temperature. The performance under real conditions was estimated as the percentile 90 of the differences between the free chlorine concentration measured by the on-line analyser, and the reference value obtained using the DPD (N,N-diethyl-1,4-phenylenediamine) method with a portable spectrophotometer, in accordance with EN 17075 standard. The VaMPIS (Validation of Measurement Procedures that Include Sampling) simultaneous approach using the duplicate method was applied to data obtained in real conditions from two on-line amperometric analysers. The measurement uncertainties estimated by both approaches agreed well, considering the confidence intervals of each of the estimates.

Peter Rostron
Setting target uncertainty in the Validation of Measurement Proedures that Include Sampling (VaMPIS), using the Optimised Uncertainty approach

Approaches to the validation of measurement procedures that include sampling have recently been published. They form a joint Eurachem / EUROLAB supplement to previous publications that focussed on validation of the analytical procedure only. These approaches require the use of a target measurement uncertainty that can be compared with the measurement uncertainty obtained by experiment. In situations where this target uncertainty is not known or specified in advance, the Optimised Uncertainty approach can provide a systematic method for calculating this value. A new program called OptiMU has been created to assist in these calculations. This is described using worked examples.

Admer Rey Dablio, Annabelle Briones, Rosemarie Salazar
A Networking Success: The Role of the Philippines’ DOST OneLab Network in Ensuring Food Safety for both the National and International Markets

In 2014, the Philippines’ Department of Science and Technology (DOST) has established the one-stop laboratory system for global competitiveness. Knowing the Philippines as an archipelagic country, with cities and communities separated by bodies of water, and with the fact that not one laboratory can cater into the wide variety of test and calibration requirements of various stakeholders, the Department decided to establish a network of testing and calibration laboratories, providing a linkage between stakeholders and the laboratories with capabilities. These laboratories are accredited by the Philippine Accreditation Bureau (PAB) of the Department of Trade and Industry (DTI), the country’s accreditation body, based on Philippine National Standard (PNS) ISO/IEC 17025:2017. The standard sets general requirements for the competence of testing and calibration laboratories. For almost a decade now, the network has already grown into 59 network member laboratories in 2023, coming from both government and private sectors, even from laboratories located in Malaysia, Thailand, Vietnam, Australia, and the United Arab Emirates (UAE). Many of these member laboratories come from testing laboratories which are being utilized to address the increasing needs from various stakeholders for testing of foods and food products to ensure safety and quality, meeting national and international requirements and standards. Through the network, micro, small and medium enterprises (MSMEs) in remote areas of the Philippines can now have access to testing services to check if their foods and food products are complying to quality requirements and are safe for consumption. This innovative solution has enabled MSMEs produce globally competitive food products able to penetrate the international market through the economies’ Mutual Recognition Arrangements (MRAs), since products are tested by accredited laboratories based on PNS ISO/IEC 17025:2017. For years, the network has helped various sectors: (a) the regulatory bodies in the performance of their function to regulate foods and food products for the strict implementation of Republic Act (RA) 10611 or the Food Safety Act of 2013; (b) the big companies and MSMEs which don’t have internal quality assurance laboratories for their food quality and safety assessments, meeting requirements of their own customers; and (c) the policy makers for the development of food safety national and international standards from scientific data of the local settings in the Philippines. As what the theme of the 2023 World Safety Day states, “Food Standards save lives,” the DOST OneLab has been influential not only in the monitoring of food safety and quality in the country, but as well as in the contribution to the development of food national standards through the technical expertise provided by DOST.

Ilya Kuselman, Tamar Gadrich, Francesca R. Pennecchi, D. Brynn Hibbert, Anastasia A. Semenova, Angelique Botha
Interlaboratory comparison of categorical characteristics of a substance, material, or object

When a reference value for the measurand in an interlaboratory study is unknown, the laboratory results may be used to estimate/build a consensus value instead of a reference value. Since no algebraic operations and mathematical functions exist among categorical (nominal and ordinal) values, a numerical consensus value cannot be formulated. Consensus of responses of experts of different laboratories participating in an interlaboratory comparison, classifying a substance, material, or object according to its nominal and ordinal characteristics, could be interpreted as the degree to which the experts agree. Two-way factorial analysis of variation of nominal variables CATANOVA and of ordinal variables ORDANOVA answer the question ‘is a consensus of participating laboratories achieved or not?’ The answer is based on testing hypotheses about homogeneity of the between- and within-laboratory variation components, as well as the variation components caused by other factors under study.