# Ensuring the Quality of the Analytical Process in a Research Laboratory
## 4 Discussion  
The present study summarized some problems and approaches to their solution in the process of ensuring the quality of results in our research laboratory. The motivation behind this study was the fact that the research laboratory performs a wide range of specific analyses, and the official guides [1; 23] for analytical method validation often could not address the entire range of issues encountered. In the research laboratory, the equipment is usually tailored to the quantity and size of the samples tested. Often, an appropriate scale-down of the analytical procedure to lower weight or volume is needed. However, it was demonstrated that the modification could alter the analytical behavior of the standard procedure used for CRM testing, as, for example, BCR sequential extraction for heavy metals fractionalization study [4; 6; 27]. Additionally, during the development of new and innovative materials, a specific analytical procedure should be developed. Often, the new or modified procedure could be only partially verified due to the lack of an appropriate CRM or well-established procedure. The example discussed here presents a study of the alkaline reactivity of geopolymer precursors as coal-combustion by-products and mine tailings. Although intensively applied, no verification data were published. Moreover, the procedures broadly differ in experimental conditions as a solid-to-liquid ratio, concentration, time of test, and instrumental method applied, thus posing a limitation of the comparability of the results [12; 13; 28]. Additionally, samples in the research laboratory are often limited in quantity, size, or number. It limits the preparation of adequate quality control charts. The recommended approach is based on the pooled sample and has the advantage of covering the range of sample characteristics for a specific object of analysis more fully [21; 23]. The cross-validation of measurement of the density of newly synthesized materials is demonstrated by a comparative study approach. In this study, two different methods were applied by the same operators in the same laboratory; however, different methods and instruments were used. The obtained results showed a difference in the obtained values for the density of samples with the same composition measured by pycnometer and hydrostatic balance methods. The difference in the obtained results was the highest for the samples with composition \((GeTe_{4})_{90}In_{10}\). Thus, applying alternative approaches to measure density could provide complementary benefits and improve confidence in measuring density. The increased discrepancy in the measured values imposed for cross-validation of the measurement of the density of newly synthesized materials. By comparing \begin{table}
\begin{tabular}{c c c} \hline \hline
**System** & **Methods** & **Value (kg/m3)** \\ \hline \((GeTe_{4})_{95}In_{5}\) & Pycnometer & \(5926\pm 3\) \\  & Hydrostatic balance & \(5993\pm 1\) \\ \hline \((GeTe_{4})_{90}In_{10}\) & Pycnometer & \(5533\pm 5\) \\  & Hydrostatic balance & \(5707\pm 1\) \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Comparison of the results of the pycnometer and the hydrostatic balance. the results obtained by the two techniques, it was possible to identify any inconsistencies or errors in any of the methods. Moreover, more appropriate measurement techniques for specific samples could be revealed. Some samples may have unique characteristics that make one method more suitable than the other. By employing both techniques, it could be ensured that different aspects and potential limitations were considered during sample characterization. The comparative study could result in a better understanding of the density particularities of new materials. Additionally, the obtained results were reliable enough to replace one method with another. Hydrostatic balances are more expensive and not easily available. In contrast, every laboratory has an analytical balance, and the pycnometer is a very cheap device.