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Byungjoo Kim, Joonhee Lee
DEVELOPMENT OF A CERTIFIED REFERENCE MATERIAL FOR THE ANALYSIS OF VITAMINS IN INFANT FORMULA

An infant formula certified reference material (CRM) for the analysis of vitamins was developed. Vitamin A, folic acid, niacin, were certified and their stability has been monitored by using isotope dilution-liquid chromatography/mass spectrometric (ID-LC/MS) methods developed in our laboratories as primary methods for the corresponding analytes. Certification of α-, δ-, and γ- tocopherols in the CRM is undergoing at the time of submitting this proceeding.

I. Castanheira, M. Roe, S. Bell, P. Colomban, M. A. Calhau, P. Finglas
METROLOGY IN FOOD COMPOSITION DATABANKS: THE EUROPEAN STRATEGY

The European Food Information Resource (EUROFIR) is a network of national Food Composition Databank (nFCDB) compilers that aims to develop, manage and publish food composition data and promote international cooperation and harmonization through improved data quality, database search ability and standards. The aim of this work is to study the role of metrology in harmonization of nFCDB. The criteria for use of nFCDBs to assist measurement processes in dietary assessment, epidemiology, food processing and food technology are described in relation to the EuroFIR quality management framework. The use of SI units of Modes of expressions and Reference Materials are the most important metrological tools to improve the quality of data in nFCDBs.

I. Delgado, C. André, A. Ramos, A.S. Matos, K.Stockham, S. Kumaran, I. Castanheira
BRACKETINS VERSUS MULTIPOINT CALIBRATION IN DETERMINATION OF ISOCYANATES IN AGGLOMERATED CORK STOPPERS

A calibration method was developed for the quantification of isocyanates in cork stoppers agglomerates. Bracketing and multipoint calibration curve was applied to a in-house optimized UPLC/DAD analytical method. The calibration curves were obtained by regression analysis using experimental points that covers the range of concentrations expected in real samples. A contaminated real sample was injected and MDI concentration was 6.2% and 6.4% when calibration methods to calculate the content were multipoint or bracketing, respectively. According with our results both methods are complementary and necessary to guarantee the reliably of results obtained by chromatographic procedure.

Jun Liu
NUTRITIONAL AND FUNCTIONAL METROLOGY IN FOOD

This paper will give an overview to the status of metrology in nutritional and functional components of food in China, covering traceability policy, CRMs, analytical methods, international comparisons, CMCs, and show a outlook.

Joonhee Lee, Byungjoo Kim
DEVELOPMENT OF A CERTIFIED REFERENCE MATERIAL FOR THE ANALYSIS OF NICOTINAMIDE IN MULTIVITAMIN

A multivitamin certified reference material (CRM) was developed for the analysis of nicotinamide. The certification value was assigned by ID-LC/MS as primary method for nicotinamide. The stability monitoring was conducted periodically, and the stability monitoring results agree with the certified value within their uncertainties.

Thomas Bruns, Philipp Begoff, Michael Mende
REALIZATION AND RESULTS OF A DKD INTERLABORATORY COMPARISON REGARDING THE MEASURAND ACCELERATION

The standard ISO/IEC 17025:2005 demands from calibration laboratories that the "participation in a suitable programme of interlaboratory comparisons is required where possible". In 2009, the working group of the German DKD concerned with acceleration and vibration decided to start such an interlaboratory comparison programme regarding the measurand acceleration and related quantities. This paper presents the set-up and organization as well as some combined results of this programme.

Rodrigo P. B. Costa-Félix, André V. Alvarenga
STATISTICAL ANALYSIS OF DIFFERENT ABSORBING TARGETS FOR ULTRASONIC RADIATION FORCE MEASUREMENT

Ultrasonic power measurement in the megahertz frequency range is undertaken according to the physical principle of radiation force. In this case, a device named "radiation force balance" is habitually used for output powers lower than about 20 W. The construction of a radiation force balance presupposes the use of either a reflecting or an absorbing target. In this paper, it is detailed a statistical analysis of 5 different absorbing targets used in an implementation of a radiation force balance measurement device. The output frequency was 3.5 MHz, and two transducers (nominal diameter of 25.4 mm and 12.7 mm) were used at nominal output power of 10 mW, 100 mW and 1 W. The measured quantities were output power and conductance radiation. Using the standard error En as parameter, in for all output setup combinations (output power and transducer diameter) the results for both quantities were considered statistically identical ( En < 1.0 ).

Mark I. Schiefer, Jeffrey Dosch
ICP® BASED REFERENCE ACCELEROMETERS

ICP® based accelerometers have become widely used in the field of vibration measurement as general purpose sensors. Charge mode accelerometers have historically been used as the reference for back to back comparison calibrations. This paper introduces the concept that the use of properly constructed ICP® based accelerometers result in a much simpler, more reliable and easier to use calibration system than charge mode accelerometer based systems. Historical data will be provided which documents the long term stability of selected ICP® reference sensors. This paper is relevant to anyone evaluating or assessing both secondary and primary accelerometer calibration system performance.

Mark I. Schiefer, Naveen Garg
LOW FREQUENCY ACCELEROMETER CALIBRATION CHALLENGES, ANALYSIS AND NEW DEVELOPMENTS

Low Frequency accelerometer calibration is generally time consuming and requires special considerations and excitation techniques. A new class of reference sensor for use in low frequency accelerometer calibration is introduced. This paper also outlines challenges of low frequency calibration and details principal sources of error. New developments in low frequency accelerometer calibration excitation technology are introduced. Comparison to manufacturers primary calibration of an artifact as well as comparison to primary means is presented.

Torben R. Licht, Soren Andresen
CALIBRATION OF FIBER OPTIC ACCELEROMETERS BY SHAKER BASED VIBRATION TEST SYSTEM

A unique type of fiber optic accelerometer based on wavelength modulation by the Bragg grating principle has been developed.
Testing, characterization and calibration of such transducers represent a challenge since they are not readily compatible with conventional data acquisition platforms.
To overcome this technical challenge a system based on a precision vibration exciter driven by a newly released vibration controller has been configured.
With this system the optical transducer system can be tested and the frequency response determined.
This shaker based vibration test system represents a very useful solution for testing any new accelerometer technology that is not directly compatible with conventional data acquisition platforms.

Page 654 of 977 Results 6531 - 6540 of 9762