Determination and speciation of inorganic As in homeopathic medicines by HG-ICP OES method with no or minimal sample treatment before measurements

Maja Welna; Anna Szymczycha-Madeja; Pawel Pohl

doi:10.1016/j.jpba.2023.115682

Determination and speciation of inorganic As in homeopathic medicines by HG-ICP OES method with no or minimal sample treatment before measurements

J Pharm Biomed Anal. 2023 Nov 30:236:115682. doi: 10.1016/j.jpba.2023.115682. Epub 2023 Aug 24.

Authors

Maja Welna¹, Anna Szymczycha-Madeja², Pawel Pohl²

Affiliations

¹ Division of Analytical Chemistry and Chemical Metallurgy, Faculty of Chemistry, Wroclaw University of Science and Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland. Electronic address: maja.welna@pwr.edu.pl.
² Division of Analytical Chemistry and Chemical Metallurgy, Faculty of Chemistry, Wroclaw University of Science and Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw, Poland.

PMID: 37660547
DOI: 10.1016/j.jpba.2023.115682

Abstract

The analysis of homeopathic medicines for the content of total inorganic As by hydride generation (HG) hyphenated with the ICP OES detection was presented. Various forms of medicaments (sugar pellets, tablets, alcohol-based drops), containing Arsenicum album or Arsenicum iodatum in several potencies (C9-200, D6-10), as well as different sample preparation approaches (wet digestion, extraction, dissolution, dilution, direct analysis) before spectrometric measurements were studied. The influence of the undecomposed sample matrix (mainly sugar and alcohol) on the HG process of As was examined in detail. Under optimal conditions found, simplified sample preparation procedures for the determination of As traces were proposed. The suitable sensitivity, the limit of detection of As < 0.1 ng g^-1, the precision within 0.31-7.4 % (as RSD), and the adequate trueness (94.9-113 % as confirmed by the recovery test) were achieved. Using the species-selective HG conditions and the developed direct analysis method, the speciation of As in arsenic drops without any prior chromatographic separation of As(III) and As(V) was carried out. The applicability of the developed strategies was demonstrated by the determination of As in 13 homeopathic products available on the Polish market.

Keywords: Homeopathic medicines; Hydride generation; Inductively coupled plasma optical emission spectrometry; Inorganic arsenic; Sample preparation; Speciation.