The LOD and LOQ values for the standard solution were respectively 0.09 and 0.31 mg L−1. For the honey samples, the LOD and LOQ values were 3.37 and 11.24 mg kg−1, respectively. In order to show the CE–UV reliability of the HMF analysis in a real sample,

a comparison was performed using the LC/MS/MS methodology analysis. Thus, a paired-samples t test was carried out, taking into account the HMF present in the honey sample. The statistical results (for n = 7) were p-value equal to 0.12 for the paired-samples t test. The Pearson correlation was 0.98, and this data, from the pairing (or matching), appears to be effective Galunisertib chemical structure with a p-value equalling 0.21 for Kolmogorov–Smirnov distance (normality test). As the p-value was higher than 0.05, no significant difference within the 95% confidence interval between

CE–UV and DNA Methyltransferas inhibitor LC/MS/MS methodologies was observed. The proposed method, after being optimised and evaluated in terms of the parameters described above, was successfully applied to determine 5-HMF in several commercially available honey samples (n = 7) which were prepared as indicated above. The honey samples were prepared in duplicate and injected in triplicate. The concentrations of 5-HMF determined for the samples are shown in Table 5. All samples, with the exception of D and Methocarbamol F, were below the concentration limit specified for this compound by Brazilian regulations (Brasil, 2000).The electropherogram of sample F is shown in Fig. 2. A MECK–UV method was developed with the aid of an experimental design to rapidly optimise the analysis time and resolution for 5-HMF separation and determination of this compound in honey samples.

Satisfactory results in relation to linearity, selectivity, precision and accuracy were obtained, which confirmed that the proposed method was suitable for this purpose. The analytical performance of the method, particularly the very short analysis time, low cost and simple sample pretreatment, verifies its potential applicability for routine and automated analysis of 5-HMF in the quality control of honeys. Overall, the results demonstrated that CE can be applied as an alternative (or complementary) technique to the recommended spectrophotometric method for application in food analysis. The authors wish to acknowledge the government agencies Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Empresa de Pesquisa Agropecuária e Extensão Rural de Santa Catarina (EPAGRI), Instituto Nacional de Ciência e Tecnologia de Catálise em Sistemas Moleculares e Nanoestruturados (INCT Catálise) and Fundação de Apoio a Pesquisa Científica do Estado de Santa Catarina (FAPESC) for financial support and fellowships.