FprEN 17767

FprEN 17767 is a CEN draft European Standard for organic and organo-mineral fertilizers. It specifies a laboratory extraction procedure using 2 % formic acid so that phosphorus can be determined later as an indicator of soft natural phosphates, mainly for laboratories testing fertilizing products and blends.

What does FprEN 17767 specify?

FprEN 17767 specifies how to extract phosphorus from different organic and organo-mineral fertilizers with formic acid before the analytical determination. It is organized into clauses on scope, normative references, terms and definitions, principle, sampling and sample preparation, reagents, apparatus, procedure, and test report.

The scope is focused on fertilizing products blends where the organic or organo-mineral fertilizer category is the highest percentage by mass or volume, or by dry mass for liquids. If another component category is present in a higher share, the European Standard for that higher-share category applies; if components are present in equal quantity, the user chooses the standard to apply.

The method is intended for cases where matrix interactions can affect analytical results. In practice, that means users should expect that blends may behave differently from single products and should watch for possible interferences when interpreting results.

What are the key requirements of FprEN 17767?

Clause 4 - principle

FprEN 17767 uses extraction with 2 % formic acid under specified conditions to distinguish hard natural phosphates from soft natural phosphates. The extract is then analysed according to prEN 17774. In practice, the extraction step is not the final measurement - it prepares the sample for the phosphorus determination.

Clause 5 - sampling and sample preparation

FprEN 17767 states that sampling is not part of the method, and it points users to EN 1482-1 and EN 1482-3 for recommended sampling methods. Sample preparation follows EN 1482-2, and the sample must represent the product and remain unchanged during transport or storage. This matters because poor sampling can distort the analytical result before the extraction even begins.

Clause 6 - reagents

FprEN 17767 requires water with low conductivity and free from the elements to be determined, and a 2 % formic acid solution prepared from concentrated formic acid and distilled water. In practice, the analyst must use clean reagents so that contamination does not affect the phosphorus result.

Clause 7 - apparatus

FprEN 17767 calls for common laboratory equipment, a 500 ml wide-neck graduated flask, an overhead shaker, and phosphate-free filter paper. The apparatus is simple, but the specified materials matter because phosphate contamination or unsuitable mixing can change the extraction outcome.

Clause 8 - procedure

FprEN 17767 specifies a 5 g test portion, with smaller portions allowed if the 1:100 sample-to-volume ratio is kept constant. The sample is extracted in formic acid at controlled temperature, shaken for 30 min, then filtered through a dry phosphate-free filter.

The procedure also requires venting gases after the initial shaking, discarding the first filtrate, and carrying out the phosphorus determination on the same day according to prEN 17774. If needed, extracts may be kept at 4 °C for up to two days. In practice, this controls reaction effects, avoids filter contamination, and limits storage changes before analysis.

Clause 9 - test report

FprEN 17767 requires the report to identify the sample, state the method used, record the sampling date and procedure if known, give the extraction completion date, and note any optional details or incidents that could influence the result. This gives traceability for laboratory records and for any later review of the test result.

What terms does FprEN 17767 define?

FprEN 17767 uses the definitions in EN 12944-1 and EN 12944-2. Key terms in the method include:

• Fertilizing product blend - a mixture of at least two components such as fertilizers, liming materials, soil improvers, growing media, inhibitors, and plant biostimulants.
• Organic fertilizers - the product category that may be the highest-share component in a blend and therefore determines which standard applies.
• Organo-mineral fertilizers - the product category targeted by the extraction method when it is the highest-share component.
• Soft natural phosphates - the phosphorus source the method is designed to help quantify after extraction.
• Hard natural phosphates - the phosphate type distinguished from soft natural phosphates by the extraction behaviour.
• Test portion - the measured amount of laboratory sample actually placed into the flask for extraction.
• ICP-AES - inductively coupled plasma atomic emission spectroscopy, the analysis technique named in prEN 17774 for the extract.

Who uses FprEN 17767?

FprEN 17767 is used by laboratory staff who analyse fertilizers and fertilizing product blends. It is also relevant to quality managers, manufacturers, and buyers who need a repeatable method for checking phosphorus-related properties in organic and organo-mineral products.

It is especially useful when products are blended and the matrix can affect the analytical result. Anyone responsible for sampling, sample preparation, extraction, or reporting of phosphorus results can use it as the common method reference.

What changed in FprEN 17767 from the previous edition?

FprEN 17767 supersedes CEN/TS 17767:2022. The foreword states these main changes:

• the CEN Technical Specification was adopted as a European Standard
• an Introduction was added
• Clause 1 was updated to clarify fertilizing product blends and the analytical method to use
• Clause 9 on test report was added
• the bibliography was updated

Which standards are used with FprEN 17767?

• prEN 17774 - gives the determination of specific elements by ICP-AES after extraction by water and weak solvents; FprEN 17767 sends the extract there for phosphorus determination.
• EN 12944-1 - provides general fertilizer and liming material vocabulary used for terms and definitions.
• EN 12944-2 - provides fertilizer-related vocabulary used for terms and definitions.
• EN 1482-2 - gives general sample preparation provisions used before extraction.
• EN 1482-1 and EN 1482-3 - are cited as recommended sampling methods in the scope and sampling clause.

What does the FprEN 17767 document contain?

FprEN 17767 contains a clear laboratory workflow for extracting phosphorus with formic acid, from sample preparation through filtration and storage to the reporting of results. It includes the principle of the method, reagent specifications, equipment, and detailed operating steps for the extraction.

The document also includes the test report items needed for traceability, so users can document the sample, the method reference, the sampling information, and any unusual events during the test. Its bibliography points to the EU fertilising products Regulation and to sampling standards that support practical use of the method.