Standard Dilution Analysis

Abstract

Standard dilution analysis (SDA) is a novel calibration method that may be applied to most instrumental techniques that will accept liquid samples and are capable of monitoring two wavelengths simultaneously. It combines the traditional methods of standard additions and internal standards. Therefore, it simultaneously corrects for matrix effects and for fluctuations due to changes in sample size, orientation, or instrumental parameters. SDA requires only 200 s per sample with inductively coupled plasma optical emission spectrometry (ICP OES). Neither the preparation of a series of standard solutions nor the construction of a universal calibration graph is required. The analysis is performed by combining two solutions in a single container: the first containing 50% sample and 50% standard mixture; the second containing 50% sample and 50% solvent. Data are collected in real time as the first solution is diluted by the second one. The results are used to prepare a plot of the analyte-to-internal standard signal ratio on the y-axis versus the inverse of the internal standard concentration on the x-axis. The analyte concentration in the sample is determined from the ratio of the slope and intercept of that plot. The method has been applied to the determination of FD&C dye Blue No. 1 in mouthwash by molecular absorption spectrometry and to the determination of eight metals in mouthwash, wine, cola, nitric acid, and water by ICP OES. Both the accuracy and precision for SDA are better than those observed for the external calibration, standard additions, and internal standard methods using ICP OES.

Expanding the potentialities of standard dilution analysis: Determination of ethanol in gasoline by Raman spectroscopy

“…Solution B was also prepared on-line by aspirating the blank and the sample (S) also at a 1:1 v/v − 1 flow ratio. These solutions were simultaneously measured in order to obtain a typical SDA curve [10]. The operation of the SDA-LLE-FA system ( Fig.…”

“…2; a new cycle can then start by aspirating the next gasoline sample. The SDA plots are constructed by using the ethanol/acetone peak area ratio (using points within the SDA region) on the y-axis versus 1/[acetone] on the x-axis [10]. Ethanol concentration in the sample (C sam ) is calculated by C sam = (slope/intercept) × (C std /C IS ), where C std and C IS are concentrations of standard (30% v/v ethanol) and internal standard (30% v/v acetone), respectively.…”

“…The recently proposed SDA method [10] combines the principles of internal standardization and standard additions calibration. It has been successfully used to determine a wide range of analytes by spectrophotometry [10] flame atomic emission spectrometry [11], inductively coupled plasma optical emission spectrometry [10,12], microwave induced plasma optical emission spectrometry [13], and inductively couple plasma mass spectrometry [14]. Because it is based on a matrix-matching, two-solution calibration strategy, SDA can significantly improve sample throughput and accuracy.…”

Combination of Multi-Energy Calibration (MEC) and Laser-Induced Breakdown Spectroscopy (LIBS) for Dietary Supplements Analysis and Determination of Ca, Mg and K

“…All the traditional calibration methods previously mentioned present drawbacks for analysis of complex samples, being in some cases necessary the application of other strategies such as multivariate calibration [25][26][27][28][29] and matrix-matching procedures. [30][31][32] Since 2011, nontraditional calibration methods, such as standard dilution analysis (SDA), [30][31][32][33] interference standard method (ISM) [34][35][36] and multi-energy calibration (MEC), 37 have been applied for quantitative analysis by inductively coupled plasma (ICP) optical emission spectrometry (OES), high-resolution continuum source (HR-CS) flame atomic absorption spectrometry (FAAS), ICP-mass spectrometry (MS) and microwave induced plasma (MIP) with OES.…”

Novel Approach to Two-Component Analysis Based on the Generalized Calibration Strategy

“…A more versatile and green solution to overcome the interferences is the application of an appropriate calibration strategy. Although this approach is not popular, some calibration procedures proposed for this purpose have recently been described in the literature Brown and Mustoe 2014;Jones et al 2015). One method dedicated to this goal developed by our team is the generalized calibration strategy (GCS) Wieczorek et al 2015).…”