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P J Farnell

Publications and source records attributed to P J Farnell.

3 recordsLinked to original sources
PubMed1997

An intercomparison of methods for the determination of ochratoxin A in pig kidney.

The preparation of two pig kidney materials is described, together with a report on the results of an intercomparison study of methods to determine ochratoxin A levels in these materials. The materials were prepared, and the intercomparison study carried out within the European Commission. Measurements and Testing Programme, which is the successor of the Community Bureau of Reference (BCR). The materials were prepared from blank and naturally-contaminated pig kidneys and were freeze-dried. Details are given on the freeze-drying and packaging procedure, and the checks to ensure homogeneity and stability of the freeze-dried materials. The intercomparison study involved 20 European laboratories, which analysed the naturally-contaminated (freeze-dried) sample (ochratoxin A content approximately 10 micrograms/ kg based on fresh weight) and the 'blank' sample (ochratoxin A content < 0.6 microgram/kg based on fresh weight) using a variety of procedures for extraction and clean-up. All laboratories used HPLC as the determinative step. Recoveries were found to range from 43 to 128%. The study highlighted problems with recovery of spiked ochratoxin A from freeze-dried pig kidney material. There is a clear need to improve analytical performance, particularly with respect to the extraction efficiency from this type of matrix.

Animals↗
PubMed1997

Ochratoxin A in wheat: certification of two reference materials.

The preparation of two wheat reference materials and the certification of their ochratoxin A content is described. The materials were prepared and certified within the European Commission. Measurements and Testing Programme (M&T). The first and second phases of this project, two intercomparisons of procedures for the determination of ochratoxin A in wheat, at levels of approximately 13 micrograms/kg, and 7 micrograms/kg, respectively have already been reported. This paper describes the work carried out in certification of the ochratoxin A content (mass fraction) of two wheat reference materials: a blank wheat CRM 471, and a contaminated wheat, CRM 472. These materials were prepared for use in the second intercomparison referred to above and reported previously. Reference material CRM 472 was prepared from naturally-contaminated wheat blended with the blank wheat (CRM 471). Details are given of the milling, blending and packaging procedure, and the checks to ensure homogeneity and stability of the material. The certification exercise was carried out by 15 laboratories using a variety of extraction and clean-up procedures, and the certified ochratoxin A content (mass fraction) of CRM 471 was < 0.6 microgram/kg. The value for CRM 472 was 8.2 micrograms/kg with an uncertainty of 1.0 microgram/kg.

Calibration↗