A study on the impact of harvesting operations on the mineral oil contamination of olive oils.

During the 2020-21 olive oil campaign, the contribution of harvesting operations to mineral oil saturated (MOSH) and aromatic hydrocarbon (MOAH) contamination was studied. Oils extracted from hand-picked olives (15 different olive groves) generally had background MOSH (<2.7 mg/kg), and no quantifiable MOAH. In 40% of the cases, an important contamination increase was observed after harvesting operations. Except for one sample (325.8 and 111.0 mg/kg of MOSH and MOAH, respectively), other samples reached 4.3-33.7 mg/kg of MOSH and 1.1-11.3 mg/kg of MOAH. Accidental leaks of lubricants and/or contact with lubricated mechanical parts, were identified as important sources of contamination. Chromatographic traces obtained by on-line high-performance liquid chromatography (HPLC)-gas chromatography (GC)-flame ionization detection (FID) allowed for source identification. A comprehensive two-dimensional gas chromatographic platform (GC × GC) with parallel FID/MS detection was implemented for confirmation and to attempt the characterization of the contaminations. Good harvesting practices are suggested to minimize contamination risks.

Delineating the extra-virgin olive oil aroma blueprint by multiple headspace solid phase microextraction and differential-flow modulated comprehensive two-dimensional gas chromatography.

Comprehensive two-dimensional gas chromatography with parallel mass spectrometry and flame ionization detection (GC × GC-MS/FID) enables effective chromatographic fingerprinting of complex samples by comprehensively mapping untargeted and targeted components. Moreover, the complementary characteristics of MS and FID open the possibility of performing multi-target quantitative profiling with great accuracy. If this synergy is applied to the complex volatile fraction of food, sample preparation is crucial and requires appropriate methodologies capable of providing true quantitative results. In this study, untargeted/targeted (UT) fingerprinting of extra-virgin olive oil volatile fractions is combined with accurate quantitative profiling by multiple headspace solid phase microextraction (MHS-SPME). External calibration on fifteen pre-selected analytes and FID predicted relative response factors (RRFs) enable the accurate quantification of forty-two analytes in total, including key-aroma compounds, potent odorants, and olive oil geographical markers. Results confirm good performances of comprehensive UT fingerprinting in developing classification models for geographical origin discrimination, while quantification by MHS-SPME provides accurate results and guarantees data referability and results transferability over years. Moreover, by this approach the extent of internal standardization procedure inaccuracy, largely adopted in food volatiles profiling, is measured. Internal standardization yielded an average relative error of 208 % for the fifteen calibrated compounds, with an overestimation of + 538% for (E)-2-hexenal, the most abundant yet informative volatile of olive oil, and a -89% and -80% for (E)-2-octenal and (E)-2-nonenal respectively, analytes with a lower HS distribution constant. Compared to existing methods based on 1D-GC, the current procedure offers better separation power and chromatographic resolution that greatly improve method specificity and selectivity and results in lower LODs and LOQs, high calibration performances (i.e., R2 and residual distribution), and wider linear range of responses. As an artificial intelligence smelling machine, the MHS-SPME-GC × GC-MS/FID method is here adopted to delineate extra-virgin olive oil aroma blueprints; an objective tool with great flexibility and reliability that can improve the quality and information power of each analytical run.

Chromatographic Fingerprinting by Template Matching for Data Collected by Comprehensive Two-Dimensional Gas Chromatography.

Data processing and evaluation are critical steps of comprehensive two-dimensional gas chromatography (GCxGC), particularly when coupled to mass spectrometry. The rich information encrypted in the data may be highly valuable but difficult to access efficiently. Data density and complexity can lead to long elaboration times and require laborious, analyst-dependent procedures. Effective yet accessible data processing tools, therefore, are key to enabling the spread and acceptance of this advanced multidimensional technique in laboratories for daily use. The data analysis protocol presented in this work uses chromatographic fingerprinting and template matching to achieve the goal of highly automated deconstruction of complex two-dimensional chromatograms into individual chemical features for advanced recognition of informative patterns within individual chromatograms and across sets of chromatograms. The protocol delivers high consistency and reliability with little intervention. At the same time, analyst supervision is possible in a variety of settings and constraint functions that can be customized to provide flexibility and capacity to adapt to different needs and goals. Template matching is shown here to be a powerful approach to explore extra-virgin olive oil volatilome. Cross-alignment of peaks is performed not only for known targets, but also for untargeted compounds, which significantly increases the characterization power for a wide range of applications. Examples are presented to evidence the performance for the classification and comparison of chromatographic patterns from sample sets analyzed under similar conditions.

A step forward in the equivalence between thermal and differential-flow modulated comprehensive two-dimensional gas chromatography methods.

Comprehensive two-dimensional gas chromatography (GC×GC) based on flow-modulation (FM) is gaining increasing attention as an alternative to thermal modulation (TM), the recognized GC×GC benchmark, thanks to its lower operational cost and rugged performance. An accessible, rational procedure to perform method translation between the two platforms would be highly valuable to facilitate compatibility and consequently extend the flexibility and applicability of GC×GC. To enable an effective transfer, the methodology needs to ensure preservation of the elution pattern, separation power, and sensitivity. Here, a loop-type thermal modulation system with dual detection (TM-GC×GC-MS/FID) used for the targeted analysis of allergens in fragrances is selected as reference method. Initially, six different columns configurations are systematically evaluated for the flow-modulated counterpart. The set-up providing the most consistent chromatographic separation (20 m x 0.18 mm dc x 0.18 µm df + 1.8 m x 0.18 mm dc x 0.18 µm df) is further evaluated to assess its overall performance in terms of sensitivity, linearity, accuracy, and pattern reliability. The experimental results convincingly show that the method translation procedure is effective and allows successful transfer of the target template metadata. Additionally, the FM-GC×GC-MS/FID system is suitable for challenging applications such as the quantitative profiling of complex fragrance materials.

Comprehensive two-dimensional gas chromatography under high outlet pressure conditions: a new approach to correct the flow-mismatch issue in the two dimensions.

The typical column sets employed in comprehensive two-dimensional gas chromatography (GC × GC) suffer from the impossibility to fully exploit the efficiency of both dimensions simultaneously. Adding a restrictor at the end of the second dimension is a possible approach to adjust the linear velocity profile. Under these high outlet pressure conditions the second dimension becomes much slower while the effect on the primary column is limited. The gap in terms of optimum inlet pressures is thus reduced. A program written in Microsoft Excel was used to calculate the efficiencies of the two dimensions in GC × GC at different outlet pressures. A GC × GC set-up with a restrictor at the end of the second dimension column was successfully installed. Experiments proved that this is a possible way to have a better exploitation of the columns. The chromatograms obtained for a number of applications confirm that the separations achieved at elevated outlet pressure are more efficient than those obtained with the same column set under atmospheric outlet conditions. The price to pay is that the separations become considerably slower.

Comprehensive two-dimensional gas chromatography with a multi-capillary second dimension: a new column-set format for simultaneous optimum linear velocity operation.

Comprehensive two-dimensional gas chromatography (GC×GC) suffers from the impossibility to operate both dimensions at their optimum carrier gas velocity at the same time due to the different inner diameters of the columns typically employed. The use of multiple parallel capillary columns in the second dimension (GC×multi-GC) is studied as a means to achieve simultaneous optimum-velocity operation. A programme written in Microsoft Excel(®) was developed to calculate the efficiency of the two dimensions in GC×multi-GC for different numbers of columns in the second dimension. With the aid of this programme the appropriate number of columns was selected. Columns with maximum repeatability were specifically manufactured to grand suitable performance, i.e. to avoid band broadening effects caused by inter-column variations. 1D-GC experiments were carried out on the columns separately and combined in parallel. The performance of the parallel column set was consistent with that of the individual columns, with over 9100 plates generated (approximately 10,000 plates/m). A GC×multi-GC set-up was successfully installed. Model experiments proved the possibility to operate both dimensions at their optimum linear velocity simultaneously. The suitability of the novel second dimension column format to perform multidimensional separations was also shown for a number of selected applications.

Macroporous polymer monoliths as second dimension columns in comprehensive two-dimensional gas chromatography: a feasibility study.

When the typical column combinations are used, comprehensive two-dimensional gas chromatography (GC×GC) suffers from the impossibility to operate both dimensions at their optimum carrier gas velocities at the same time. This as a result of the flow mismatch caused by the different dimensions of the columns used. The objective of the present study was the development of monolithic second dimension columns which would allow simultaneous optimum-velocity operation. With monolithic GC columns the optimum performance can be obtained at any given flow rate by varying the bed structure and column diameter. Different divinylbenzene-based monolithic columns were prepared and evaluated in terms of permeability and performance. Plate heights of less than 0.18 mm and plate generation rates up to 600 plates/s were achieved. 1D-GC experiments performed on short monolithic columns showed a good resolving power thanks to the elevated retention and the good selectivity. A peak capacity up to 12 peaks per 4-5s was obtained for low-boiling alkanes, confirming the potential for fast separations. Excellent repeatability in terms of retention times (RSD<0.5%) and peak widths (RSD<1.5%) was observed. The columns prepared were successfully used in the second dimension of a GC×GC setup with a standard non-polar first dimension. Model experiments proved the possibility to operate both dimensions at their optimum linear velocity simultaneously. The suitability of the novel second dimension column format to perform multidimensional separations was shown for selected applications.

Hydrophobic polymer monoliths as novel phase separators: application in continuous liquid-liquid extraction systems.

Hydrophobic macroporous polymer monoliths are shown to be interesting materials for the construction of "selective solvent gates". With the appropriate surface chemistry and porous properties the monoliths can be made permeable only for apolar organic solvents and not for water. Different poly(butyl methacrylate-co-ethylene dimethacrylate) (BMA-EDMA) and poly(styrene-co-divinylbenzene) (PS-DVB) monoliths prepared with tailored chemistries and porosities were evaluated for this purpose. After extensive characterization, the PS-DVB monoliths were selected due to their higher hydrophobicity and their more suitable flow characteristics. BMA-EDMA monoliths are preferred for mid-polarity solvents such as ethyl acetate, for which they provide efficient separation from water. Breakthrough experiments confirmed that the pressures necessary to generate flow of organic solvents through PS-DVB monoliths were substantially lower than for water. A phase separator was constructed using the monoliths as the flow selector. This device was successfully coupled on-line with a chip-based continuous liquid-liquid-extraction (LLE) system with segmented flow. Efficient separation of different solvents was obtained across a wide range of flow rates (0.5-4.0 mL min(-1)) and aqueous-to-organic flow ratios (ß=1-10). Good robustness and long life-time were also confirmed. The suitability of the device to perform simple, cheap, and reliable phase separation in a continuous LLE system prior to gas-chromatographic analysis was proven for some selected real-life applications.

Advancing liquid/liquid extraction through a novel microfluidic device: theory, instrumentation and applications in gas chromatography.

A new chip-based liquid-liquid extraction technique for sample preparation of aqueous samples for GC was developed. Extraction is performed in a segmented flow system with additional mixing provided by an etched channel structure. The dimensions of the device are optimized to allow benefiting of the advantages of chip technology without suffering from the limitations of over-miniaturization. Phase separation is performed with a novel phase separator developed in house. The instrumental set-up is simple. The results obtained for selected test analytes show that the extraction is quantitative (recoveries = 92-110%, RSD < 6%) for a wide range of hydrophobicities (LogK(o/w) = 0.86-4.79). The performance at different flow rates (0.5-6.0 mL/min) and flow ratios (ß = 1-10) was evaluated, confirming the flexibility and the possibility to perform enrichment. The results obtained for a few selected applications demonstrate the suitability of the method to perform quick, simple and reliable sample preparation for analytes of interest in real samples.

Enfermedad de Darier / Darier`s Disease

La enfermedad de Darier es un desorden de herencia autosómica dominante infrecuente, caracterizado por pápulas foliculares y perifoliculares y placas queratósicas distribuidas en áreas seborreicas que generalmente se manifiesta en la adolescencia. Se acompaña, además, de compromiso ungueal y mucoso. Se presentan tres pacientes con un cuadro clínico e histopatológico compatible con enfermedad de Darier evaluados en el Servicio de Dermatología del Hospital de Pediatría “Prof. Dr. Juan P. Garrahan”entre agosto de 1988 y mayo de 2010.La media de las edades al momento del diagnóstico fue de 11,33 años. La totalidad de los pacientes presentó manifestaciones cutáneas y ungueales características de la enfermedad. El 100% de los pacientes recibió tratamiento con emolientes, y a dos de ellos se les asoció retinoides tópicos, ácido láctico y/o urea. Es importante recordar que ante un paciente con estas características clínicas debe sospecharse esta enfermedad para poder instaurar un tratamiento oportuno.

[Detection of arterial hypertension in school childrens]. / Detección de hipertensión arterial en niños en edad escolar.

INTRODUCTION: Hypertension is a multifactorial desease, with increasingly incidence and prevalence, that is why it is considered a public health issue. OBJECTIVES: To know the prevalence of hypertension in children from 6 to 12 years old, in Cipolletti city. To check if there are differences as regards sex and age. To institutionalizalice blood pressure messurement as part of the rutinary physical examination in the control of a child. METHODS AND MATERIALS: This was a cross sectional study. Blood pressure readings were obteined from 1038 students aged between 6 and 12 years old; who belong to 7 public schools of Cipolletti. Mercury sphyngomanometer and cuffs of 7.5 per 15 cm and 12 per 22 cm were used. The auscultatory method was used in phase I and V of Korotkoff. The second Task Force recomendations for blood pressure in children were followed. Blood pressure readings were obteined in 3 visits. Those students who had blood pressure messurement iqual to or higher than those established for hypertension were identified during each visit: boys 115/75 mmHg (6-8 years) 118/79 mmHg (9-10 years) and 122/80 mmHg (11-12 yars); girls 113/74 mmHg (6-8 years) 118/79 mmHg (9-10 years) and 122/79 mmHg (11-12). RESULTS: The prevalence of hypertension is 3.37%, being more frecuent in the range of ages that go from between 6 to 8 years, which corresponds to a 74.29% of the hypertensed children. The hypertense group messurements of blood pressure are: a)Boys: 122.92 mmHg +/- 4.11/78.43mmHg +/- 5.19; b)Girls: 123.63 mmHg +/- 7.43/80.22mmHg +/- 2. There were not significant differences between sexs at the 5% (a=0.05) level. The blood pressure has never been messurered to 597 students (58%). CONCLUSIONS: The prevalence of hypertension in Cipolletti is similar to international statistics. There is a number of children with hypertension that is not detected during medical examination due to lack of blood pressure messurement institutionalization.

Detección de hipertensión arterial en niños en edad escolar / Detection of arterial hypertension in school childrens

INTRODUCCIÓN: La Hipertensión Arterial (HTA) es un padecimiento multifactorial, con incidencia y prevalencia crecientes, por lo que se considera un problema de salud pública. OBJETIVOS: Conocer la prevalencia de HTA en niños de 6 a 12 años, en la ciudad de Cipolletti. Comprobar si existen diferencias en cuanto a sexo y edad. Institucionalizar la toma de Tensión Arterial (TA) como parte del examen físico de rutina en el control del niño. MATERIAL Y MÉTODOS: El estudio fue de tipo corte transversal, a partir de una muestra de 1038 alumnos con edades comprendidas entre 6 y 12 años, pertenecientes a 7 establecimientos públicos de la ciudad de Cipolletti. Se utilizó esfingomanómetro mercurial y brazaletes de 7.5 x 15 cm. y de 12 x 22 cm.. Se empleó el método auscultatorio en fase 1 y V de Korotkoff. Se siguieron las recomendaciones de la Second Task Force for Blood Pressure in Children. La toma de la TA se realizó en tres visitas, en cada una de ellas se identificó aquellos alumnos que se encontraban en valores iguales o mayores a los establecidos para hipertensión: Niños:115/75 mmHg (6-8 años); 118/79 mmHg(9-1O) y 122/80 mmHg (11-12). Niñas: 113/74 mmHg (6-8 años); 118/77 mmHg (9-10) y 122/79 mmHg (1112). RESULTADOS: La prevalencia HTA es del 3.37%. Siendo más frecuente en el rango de edades comprendidas entre los 6 y 8 años, correspondiendo a un 74.29% de los hipertensos. Las medias de TA para el grupo de hipertensos son: a) varones: 122.92 mmHg:!:: 4.1l/78.43 mmHg:!:: 5.19; b) mujeres: 123.63 mmHg :!:: 7.43/ 80.22 mmHg :!:: 2. No existen diferencias significativas al nivel del 5% (á = 0.05) entre sexos. A 597 (58%) estudiantes nunca se les había tomado la tensión arterial. CONCLUSIONES: La prevalencia de HTA en Cipolletti es similar a las estadísticas internacionales. Hay un número de niños hipertensos que no se detectan en la consulta debido a la falta de institucionalización de la toma de la tensión arterial.

INTRODUCTION: Hypertension is a multifactorial disease, with increasingly incidence and prevalence, that is why it is considered a public health issue. OBJECTNES: To know the prevalence of hypertension in children from 6 to 12 years old, in Cipolletti city. To check if there are differences as regards sex and age. To institutionalizalice blood pressure measurement as part of the rutinary physical examination in the control of a child. METHODS AND MATERlALS: This was a cross sectional study. Blood pressure readings were obtained from 1038 students aged between 6 and 12 years old; who belong to 7 public schools of Cipolletti. Mercury sphyngomanometer and cuffs of 7.5 per 15 cm and 12 per 22 cm were used. The auscultatory method was used in phase 1 and V of Korotkoff. The second Task Force recommendations for blood pressure in children were followed. Blood pressure readings were obtained in 3 visits. Those students who had blood pressure measurement iqual to or higher than those established for hypertension were identified during each visit: boys 115/ 75 mmHg (6-8 years) 118/79 mmHg (9-10 years) and 122/80 mmHg (11-12 years) ; girls 113/74 mmHg ( 6-8 years) 118/79 mmHg ( 9-10 years) and 122/79 mmHg (11-12). RESULTS: The prevalence of hypertension is 3.37%, being more frequent in the range of ages that go from between 6 to 8 years, which corresponds to a 74.29% of the hypertensed children. The hypertense group measurements of blood pressure are: a)Boys: 122.92 mmHg :!: 4.11/78.43mmHg :!: 5.19; b)Girls: 123.63 mmHg:!: 7.43/80.22mmHg:!: 2. There were not significant differences between sexes at the 5% (a=0.05) level!. The blood pressure has never been measurered to 597 students (58%). CONCLUTIONS: The prevalence of hypertension in Cipolletti is similar to international statistics. There is a number of children with hypertension that is not detected during medical examination due to lack of blood pressure measurement institutionalization.