Related Experiment Video
Updated: Jun 5, 2026
13:48
Design and Construction of an Urban Runoff Research Facility
Published on: August 8, 2014
Review of sodium analysis proficiency test results
1The Food and Environment Research Agency, Sand Hutton, York YO41 1LZ, UK. mark.sykes@fera.gsi.gov.uk
Summary
Food sodium analysis proficiency testing reveals challenges, particularly with fruit juice and tomato sauce. Laboratories struggle to achieve satisfactory z-scores due to issues in determining accurate sodium values.
Area of Science:
- Food chemistry
- Analytical chemistry
- Laboratory proficiency testing
Background:
- Proficiency testing (PT) for sodium analysis in various food matrices has highlighted concerns regarding laboratory performance.
- A significant proportion of laboratories fail to achieve satisfactory z-scores, indicating potential issues in sodium determination accuracy.
Purpose of the Study:
- To evaluate the performance of laboratories in sodium analysis across different food types.
- To identify specific food matrices and analytical methods that pose challenges in achieving accurate sodium quantification.
Main Methods:
- Analysis of proficiency testing data for sodium in diverse food samples including fruit juice, canned meat, tomato sauce, cheese, and snack foods.
- Evaluation of assigned values, uncertainty, and z-scores based on the Horwitz equation for standard deviation of proficiency.
- Assessment of the influence of accreditation status, digestion methods (microwave vs. acid), and determination techniques (flame atomic absorption spectroscopy, flame photometry, inductively coupled plasma spectroscopy).
Main Results:
- Fruit juice and tomato sauce presented the most significant challenges for deriving assigned values with low uncertainty, impacting z-score evaluation.
- The standard deviation for proficiency was primarily based on the Horwitz equation due to limited collaborative trial data for these matrices.
- Accreditation status did not appear to influence the variation in results. Flame photometry use in juice analysis may lead to overestimated sodium results due to potassium interference or reporting errors.
Conclusions:
- Sodium analysis in certain food matrices, especially fruit juice and tomato sauce, requires improved methodologies for accurate quantification.
- The choice of determination method is matrix-dependent, and potential interferences (e.g., potassium in flame photometry) must be carefully managed.
- Further research and method development are needed to enhance the reliability of sodium analysis in complex food samples during proficiency testing.
Related Concept Videos
03:46Qualitative Analysis
For solutions containing mixtures of different cations, the identity of each cation can be determined by qualitative analysis. This technique involves a series of selective precipitations with different chemical reagents, each reaction producing a characteristic precipitate for a specific group of cations. Metal ions within a group are further separated by varying the pH, heating the mixture to redissolve a precipitate, or adding other reagents to form complex ions.
For instance, group IV...
For instance, group IV...
01:19Quality Assurance
Quality assurance is the overarching term used to describe the activities employed to ensure the proper performance of a system. These activities can be classified into three categories: quality control, quality assessment, and internal corrective measures. Typically, these activities work cyclically: quality control is performed before and during the analysis, while quality assessment occurs during and after the investigation. Internal corrective measures are implemented based on the findings...
01:21Development of Analytical Methods
An analytical methodology can be divided into four sequential steps: technique, method, procedure, and protocol. A technique is a scientific principle that rationalizes a specific phenomenon through chemical measurements. Adapting a technique for analyzing a sample of interest is termed a method. The procedure outlines the directions for performing the analysis via an analytical method. The protocol is the detailed guidelines on the procedure, which should be strictly followed to obtain the...
01:12Quantitative Analysis
Quantitative analysis is a technique for measuring the amount of specific constituents in a sample. When the sample's composition is unknown, qualitative analysis is performed first to identify its components, which ensures that the correct substances are measured during the quantitative phase.
In quantitative analysis, two key measurements are made: the sample quantity and a property proportional to the amount of the analyte (the substance being analyzed). This forms the basis of the method...
In quantitative analysis, two key measurements are made: the sample quantity and a property proportional to the amount of the analyte (the substance being analyzed). This forms the basis of the method...
01:15Data Validation
Method validation is a crucial process in analytical chemistry designed to confirm that a given method consistently produces reliable and high-quality results. This process is essential when a method is applied to different sample matrices or when procedural modifications are made, ensuring that the results meet acceptable standards across various applications.
Key parameters for method validation include:
Key parameters for method validation include:
01:14Testing Water Quality
When the quality of water for concrete preparation is uncertain, its impact on the setting time of cement and compressive strength of mortar is assessed by comparison with de-ionized or distilled water benchmarks. American Society for Testing and Materials (ASTM) C1602 requires the setting times to be within 90 minutes of the control, British Standard (BS) 3146:1980 allows a 30-minute variance in the initial setting, while British Standards European Norm (BS EN) 1008 specifies initial setting...