RESUMO

Solid-phase microextraction and comprehensive multidimensional gas chromatography represent two milestone innovations that occurred in the field of separation science in the 1990s. They have a common root in their introduction and have found a perfect coupling in their evolution and applications. This review will focus on food analysis, where the paradigm has changed significantly over time, moving from a targeted analysis, focusing on a limited number of analytes at the time, to a more holistic approach for assessing quality in a larger sense. Indeed, not only some major markers or contaminants are considered, but a large variety of compounds and their possible interaction, giving rise to the field of foodomics. In order to obtain such detailed information and to answer more sophisticated questions related to food quality and authenticity, the use of SPME-GC × GC-MS has become essential for the comprehensive analysis of volatile and semi-volatile analytes. This article provides a critical review of the various applications of SPME-GC × GC in food analysis, emphasizing the crucial role this coupling plays in this field. Additionally, this review dwells on the importance of appropriate data treatment to fully harness the results obtained to draw accurate and meaningful conclusions.

Assuntos

Análise de Alimentos , Compostos Orgânicos Voláteis , Microextração em Fase Sólida/métodos , Cromatografia Gasosa , Cromatografia Gasosa-Espectrometria de Massas/métodos , Qualidade dos Alimentos , Compostos Orgânicos Voláteis/análise

RESUMO

Since its introduction comprehensive two-dimensional gas chromatography (GC × GC) has been widely applied to analyze complex samples due to its enhanced peak capacity and selectivity, thereby increasing the number of identifiable peaks and improving coelution issues. Even though it is still undergoing development, GC × GC provides many advantages in the analysis of petroleum-derived samples, whether in reservoir geochemistry applications or in environmental studies associated with spilled oils. In general, it facilitates more thorough fingerprinting and compositional evaluation. In environmental studies, it helps enhance understanding of weathering processes and the environmental behavior of hydrocarbons, as its chromatographic retention indices can robustly estimate liquid vapor pressures, aqueous solubility and other physical chemical properties. This review presents a brief history of GC × GC instrumentation, discussing recent and significant advances in petroleum applications, from data handling techniques to reservoir geochemistry and environmental forensics, as well as some specific advantages achieved and certain limitations that continue to be encountered.

RESUMO

Pesticides are traditionally analyzed using conventional gas chromatography. When fast chromatography is associated with comprehensive two-dimensional gas chromatography (GC × GC), the resulting method presents high-resolution separation associated with a higher chromatographic speed. In the present work, a method for pesticide analysis in sediment samples was developed using quick, easy, cheap, effective, rugged, and safe extraction (QuEChERS) and a hyperspeed GC × GC separation. The QuEChERS procedure reported in the literature was extended to incorporate the analytes tetrachloro-m-xylene, decachlorobiphenyl, trans-chlordane, chlordane, endosulfan lactone, and endosulfan ether. To understand the chromatographic method improvement achieved, the recent concept of average theoretical peak time (ATPT) was used. The ATPT improved from that of the traditional GC × GC separation to the proposed method, and the separation speed can be classified as a hyperspeed separation. The limit of detection and quantitation of the compounds in the standard mix ranged from 0.39 to 17.96 µg L-1 and 1.18 to 54.43 µg L-1, respectively. The method showed acceptable RSD% (relative standard deviation) values and little interference of the sediment matrix in the extraction procedure. The developed method was applied to the determination of a mixture of 19 compounds in 16 sediment samples from the Pirapetinga River and Paraíba do Sul River in Brazil.

RESUMO

The essential oil (EO) from the leaves of Zanthoxylum caribaeum (syn. Chiloperone) (Rutaceae) was studied previously for its acaricidal, antimicrobial, antioxidant, and insecticidal properties. In prior studies, the most abundant compound class found in leaf oils from Brazil, Costa Rica, and Paraguay was terpenoids. Herein, essential oil from the leaves of Zanthoxylum caribaeum (prickly yellow, bois chandelle blanc (FWI), peñas Blancas (Costa Rica), and tembetary hu (Paraguay)) growing in Guadeloupe was analyzed with comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC × GC-TOFMS), and thirty molecules were identified. A comparison with previously published leaf EO compositions of the same species growing in Brazil, Costa Rica, and Paraguay revealed a number of molecules in common such as ß-myrcene, limonene, ß-caryophyllene, α-humulene, and spathulenol. Some molecules identified in Zanthoxylum caribaeum from Guadeloupe showed some antimetabolic effects on enzymes; the in-depth study of this plant and its essential oil with regard to metabolic diseases merits further exploration.

RESUMO

Morinda citrifolia is a plant that grows in Brazilian northeast and presented a wide range of therapeutic, industrial and technological applications. Based on this, the aim of this work was to study the chemical composition, main biological activities and potential toxicity of its extracts, aiming their industrial application. Important compounds were identified in the methanolic extracts obtained by ultrasonic and Soxhlet extractions from leaves and fruits. GC × GC allowed for the identification of phytosterols, fatty acids and methyl esters, besides others (scopoletin, hydrocarbons, alcohols, terpenes). By HPLC-DAD, compounds like catechin, rutin, quercetin could be also identified and quantified. Their content of polyphenols and flavonoids was considered between the international standards. The extracts showed high antioxidant activities (EC50 ∼ 300 µg mL-1, using DPPH assay) compared with those from the literature. The extracts did not show toxicity or mutagenicity, but presented cytotoxicity, which can indicate their use safely in phytotherapic or nutritional applications.

Assuntos

Antineoplásicos , Morinda , Morinda/química , Frutas/química , Metanol , Extratos Vegetais/química , Folhas de Planta/química , Antineoplásicos/análise

RESUMO

The current methodology used in quality control of Ecuadorian beverages such as Pájaro azúl, Puro and Pata de vaca is carried out by using conventional gas chromatography; however, it does not allow the fingerprinting of these Ecuadorian spirit beverages and their possible cases of adulteration. In order to overcome this drawback, comprehensive two-dimensional gas chromatography-mass spectrometry (GC × GC-MS) was combined with multivariate data analysis, revealing that compounds like citronellal, citronellol, geraniol, methyl anthranilate, (-)-trans-α-bergamotene, (-)-cis-α-bergamotene and D-limonene can be considered key elements for pattern recognition of these traditional beverages and product adulteration cases. Thus, the two-dimensional chromatographic fingerprints obtained by GC × GC-MS coupled with chemometric analysis, using Principal Component Analysis and Fisher-ratio can be considered as a potential strategy for adulteration recognition, and it may used as a quality assurance system for Ecuadorian traditional spirits.