Validation of the use of an automatic diluter in HPLC analyses by comparison with traditional methods

Abstract

Abstract. In an analysis protocol, dilution is nowadays the last step that is never (or seldom) fully automated. Yet special appliances called diluters are commercially available. In spite of the potential advantages in time and solvent saving, analysts are still reluctant to use these diluters, mainly because of the insufficient proof that they are able to give accurate and precise results. Validation by gravimetry did not represent an irrevocable argument since it could not account for memory effect. That is the reason why we chose to carry out our validation of the dilution step in HPLC analyses with an automatic diluter through a comparison with classical methods using flasks and pipettes or burettes. A parent solution made of concentrated Spiramycin was diluted by the various methods. The control analysis was operated using HPLC with UV detection. The experimental design involved two operators and results obtained were processed using statistical tools such as ANOVA and regression. Conclusions were that in any case the diluter was at least as effective as traditional methods. Observed variability introduced by dilution was 0.30% RSD with diluter, and 0.45% RSD with classical methods. In addition, as was shown by the results of the lack of fit test, diluter accuracy is quite compatible with linearity studies in HPLC. Consequently, it is possible and even advantageous to use a diluter instead of manual methods.

New approach of validation using internal normalization technique for quantification of related substances in raw material, intermediates and pharmaceutical substances by HPLC

“…The dilution solution used was methanol. Dilutions were carried out using pipette and volumetric flask [11]. The sample solutions of prasugrel (sample I) at concentration of 0.8; 1.0 and 1.2 mg/ml were prepared for evaluation of validation parameter of precision.…”

Study of the Linear Range in HPLC Analyses with UV Detection: Methodology and Experimental Application to the Influence of the Analyte UV Spectrum

“…For each experiment, a parent solution of spiramycin at the 700% level was prepared by dissolving 175 mg of spiramycin powder in 100 mL of a mixture of water and acetonitrile at 70 : 30 v : v. Each individual sample was then prepared by dilution from the parent solution with the help of an automatic diluter, the Hamilton 530B [24]. It was equipped with two syringes, the volumes of which depended on the expected dilution ratio.…”