Determination of sodium tripolyphosphate in meat samples by capillary zone electrophoresis with on-line isotachophoretic sample pre-treatment

The usefulness of zone capillary electrophoresis (CZE) in combination with isotachophoresis (cITP) as on-line preconcentration technique was examined for analysis of tripolyphosphate (STPP) in meat and meat products. The mean concentrations of STPP in different types of meat products varied from 39 mg P₂O₅/100 g to 219 mg P₂O₅/100 g, these values are below the legal requirements. The detection (LOD) and quantification (LOQ) limits for STPP in extracted solutions were 0.80 mg P₂O₅/dm³ and 2.69 mg P₂O₅/dm³, respectively. Obtained results were compared with the Kjeldahl method. Accuracy (97.4-98.3%) was determined using recovery assay based on standard additions method. Precision was evaluated by within-day R.S.D. (1.40-2.19%), between-days R.S.D. (3.00-3.82%) and demonstrates the benefit of using this procedure for the routine analysis of STPP in meat and their products. The F-Snedecor test was employed to compare the precision of the used methods and calculated F-test values (4.00, 6.13) were less than the theoretical (6.39).