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E Bonet-Domingo

Publications and source records attributed to E Bonet-Domingo.

4 recordsLinked to original sources

A diagnostic tool for determining the quality of accuracy validation. Assessing the method for determination of nitrate in drinking water.

Realistic internal validation of a method implies the performance validation experiments under intermediate precision conditions. The validation results can be organized in an X (NrxNs) (replicates x runs) data matrix, analysis of which enables assessment of the accuracy of the method. By means of Monte Carlo simulation, uncertainty in the estimates of bias and precision can be assessed. A bivariate plot is presented for assessing whether the uncertainty intervals for the bias (E +/- U(E)) and intermediate precision (RSDi +/- U(RSDi) are included in prefixed limits (requirements for the method). As a case study, a method for determining the concentration of nitrate in drinking water at the official level set by 98/83/EC Directive is assessed by use of the proposed plot.

Bias↗

Uncertainty-based internal quality control. Harmonization considerations.

Three main quality aspects for analytical laboratories are internal method validation, internal quality control (IQC), and sample result uncertainty. Unfortunately, in the past they have been used in a nonharmonized way. The most universal IQC tool is the mean chart, but some criteria used to fix their control limits do not fit the real nature of analytical results. A new approach for fixing these limits is proposed (the u-approach). The key is the combined uncertainty, u, obtained from the method validation information, also used for estimating the sample result uncertainty. A comparative study on "in-control" simulated, bibliographic, and real laboratory data suggests that the u-approach is more reliable than other well-established criteria. In addition, the u-approach mean chart emerges as an IQC tool, consistent with chemical assays, which harmonizes the validation-control-uncertainty process.

Journal Article↗

Multivariate data analysis of quality parameters in drinking water.

The quality of water destined for human consumption has been treated as a multivariate property. Since most of the quality parameters are obtained by applying analytical methods, the routine analytical laboratory (responsible for the accuracy of analytical data) has been treated as a process system for water quality estimation. Multivariate tools, based on principal component analysis (PCA) and partial least squares (PLS) regression, are used in the present paper to: (i) study the main factors of the latent data structure and (ii) characterize the water samples and the analytical methods in terms of multivariate quality control (MQC). Such tools could warn of both possible health risks related to anomalous sample composition and failures in the analytical methods.

Multivariate Analysis↗

A micellar liquid chromatographic procedure for the determination of amiloride, bendroflumethiazide, chlorthalidone, spironolactone and triamterene in pharmaceuticals.

A procedure for the determination of amiloride, bendroflumethiazide, chlorthalidone, spironolactone and triamterene in pharmaceutical preparations (tablets) by micellar liquid chromatography, using a 0.07 M SDS-0.5% pentanol mobile phase, is proposed. Recoveries were found in the 100-108% range, with relative standard deviations of 0.4-3.1%. Elution of the most retained diuretics occurred in less than 18 min (at a 1 ml min-1 flow rate). The change in the values of the solute-micelle binding constants and the partition coefficients of the diuretics between the stationary phase and water, upon addition of pentanol, was also studied.

Amiloride↗