Use of elemental profiles determined by energy-dispersive X-ray fluorescence and multivariate analyses to detect adulteration in Ceylon cinnamon.

The price of Cinnamomum verum (Ceylon cinnamon) is around twice as high as that of the other cinnamon varieties commonly grouped under the name cassia cinnamon, making the former spice an attractive target for fraudsters. This work demonstrates that elemental profiles obtained by energy-dispersive X-ray fluorescence in combination with multivariate analyses can be used as a screening method to detect Ceylon cinnamon adulteration. Thirty-six elements were analysed in 52 commercially available cinnamon samples, 29 Ceylon, 8 cassia, and 15 for which no indication about variety was provided. Fifty-eight percent of the samples were either adulterated or did not meet international quality criteria. Four of the ground cinnamon samples labelled as Ceylon cinnamon were found to be pure cassia or a mixture with a high cassia content, and 26 samples were suspected of other types of adulteration including replacement of bark with other parts of the cinnamon tree. Headspace gas chromatography-mass spectrometry and ash determination by thermogravimetric analysis confirmed the conclusions reached by elemental analysis. Only one sample labelled as Ceylon cinnamon and that according to its volatile composition was cassia cinnamon was not flagged as suspicious by elemental analysis.

Are the elemental fingerprints of organic and conventional food different? ED-XRF as screening technique.

Research has been conducted the last years to assess whether organically grown food is chemically different from produce of conventional agriculture and which markers are appropriate to discriminate between them. Most articles focus on one single food commodity, produced under strict controlled organic farming conditions, leaving open the question whether the difference would be seen when applied to the same commodity under different growing conditions. In this work 118 organic and 151 conventional samples of commercially available paprika powder, cinnamon, coffee, tea, chocolate, rice, wheat flour, cane sugar, coconut water, honey and bovine milk were characterised for their elemental composition using energy dispersive X-ray fluorescence. Resulting profiles were analysed using univariate and multivariate statistical techniques. Organic samples of a given commodity clustered together and were separated from their conventional counterparts. Differences in the elemental composition of food, could be used to develop statistical models for verifying the agronomical production system.

Feasibility study on the use of elemental profiles to authenticate aromatic rice: the case of Basmati and Thai rice.

Among the thousands of existing rice varieties, aromatic rice has increasingly attracted consumer's preference in recent years. Within aromatic rice, Basmati, cultivated in some regions in Pakistan and India, is highly demanded. Other aromatic rice, cultivated in specific regions, for instance in Thailand (commonly referred to as Jasmine Thai rice), are also highly appreciated by consumers. In this work, the elemental profiles of commercially available rice samples (17 Basmati, 11 Thai, and 7 Long Grain rice) were determined by energy-dispersive X-ray fluorescence (ED-XRF) spectroscopy. The mass fractions of P, Cl, S, K, Fe, Cu, and Zn were significantly different (95% confidence interval) between Basmati and Thai rice and between Thai and Long Grain rice; only Cl, S, and Zn were significantly different between Basmati and Long Grain rice. Multivariate evaluation of the results combining soft independent modelling by class analogy (SIMCA) and partial least square discriminant analysis (PLS-DA) allowed the correct classification (true positives) of 94.1, 85.6, and 100% of the Basmati, Long Grain, and Thai rice, respectively. The specificity (true negatives) of Basmati, Long Grain, and Thai was 94.4, 82.1, and 100%, respectively.

Use of energy-dispersive X-ray fluorescence combined with chemometric modelling to classify honey according to botanical variety and geographical origin.

Honey is one of the food commodities most frequently affected by fraud. Although addition of extraneous sugars is the most common type of fraud, analytical methods are also needed to detect origin masking and misdescription of botanical variety. In this work, multivariate analysis of the content of certain macro- and trace elements, determined by energy-dispersive X-ray fluorescence (ED-XRF) without any type of sample treatment, were used to classify honeys according to botanical variety and geographical origin. Principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) were used to create classification models for nine different botanical varieties-orange, robinia, lavender, rosemary, thyme, lime, chestnut, eucalyptus and manuka-and seven different geographical origins-Italy, Romania, Spain, Portugal, France, Hungary and New Zealand. Although characterised by 100% sensitivity, PCA models lacked specificity. The PLS-DA models constructed for specific combinations of botanical variety-country (BV-C) allowed the successful classification of honey samples, which was verified by external validation samples. Graphical abstract.

Determination of haemoglobin A(1c) by liquid chromatography using a new cation-exchange column.

The use of a new cation-exchange column, ProPac SCX-10, for the determination of haemoglobin A(1c) (HbA(1c)) by high-performance liquid chromatography is described. After optimization of the analytical method for the separation of the various isoforms of haemoglobin with the ProPac SCX-10 column, the method was applied to the determination of HbA(1c) in blood from 59 volunteers. Three of the 59 had previously been diagnosed as diabetics. Interference studies for carbamylation, acetylation and pre-HbA(1c) were carried out via "in-vitro" experiments. No interference due to carbamylation was observed at the urea values normally found in uremic patients undergoing dialysis. No interference from pre-HbA(1c) was detected either. The method is able to separate haemoglobin A (alpha(2)beta(2)), haemoglobin S (haemoglobin from sickle cell anaemia patients) and haemoglobin A(2) (alpha(2)delta(2)) without interference. The method of Hampel was applied to detect outliers. A value of 3.29+/-0.44% (2sigma) for HbA(1c) was obtained in the analysis of 56 blood samples from non-diabetics. This average value is lower than that reported by most of the methods currently used in routine analyses.

Uso de antibióticoterapia y evolución de diarreas infantiles producidas por shigella / Use antibiotic treatment and the effect over the acute diarrhea caused by shigella

En el presente trabajo se estudió la etiología de la diarrea aguda infantil y se analizaron los efectos de la antibióticoterapia en la duración de la diarrea aguda causada por Shigella. Fue conducido en el Hospital Materno Infantil de Caricuao, ubicado al oeste de Caracas. Se estudiaron 1358 episodios diarreicos entre el 01 de julio de 1993 y el 31 de mayo de 1995, a los cuales se les practicó un registro clínico diario y un estudio de laboratorio que incluyó: examen microscópico de heces, coprocultivo con su respectivo antibiograma y ensayo inmunoenzimatico (ELISA) para Rotavirus. De los 1358 episodios: 304 (22,38 por ciento) fueron causados por Rotavirus, 216 (15,90 por ciento) por Campylobacter, 110 (8,10 por ciento) por Escherichia coli patógenas (E.coli enteropatógena: 3,40 por ciento, E.coli enterotoxigénica: 4,40 por ciento y E.coli enteroinvasiva: 0,28 por ciento) 30 (2,20 por ciento) de Salmonella y 91 (6,7 por ciento) episodios fueron causados por Shigella. En 80,21 por ciento (73/91) de los casos se aisló Shigella como único agente presente en el coprocultivo. Las especies de Shigella aisladas fueron las siguientes: 49 (67,12 por ciento) de Shigella flexneri, 23 (31,50 por ciento) de Shigella sonnei y 1 (1,32 por ciento) de Shigella boydií. El 47,95 por ciento de los episodios ocurrió en menores de 6 meses, 17,80 por ciento en niños de 6 a 12 meses y 34,25 por ciento en mayores de 1 año. La sintomatología asociada al episodio diarreico incluye: fiebre (65,75 por ciento), vómitos (50,68 por ciento), heces con moco y sangre (64,38 por ciento) y deshidratación moderada o severa (31,50 por ciento). En el tratamiento de las diarreas agudas con antibióticoterapia se utilizaron diferentes combinaciones de antimicrobianos, las más frecuentes fueron: AM-NA (9,3 por ciento), AM-SAM (4,6 por ciento) y AM-CE (4,6 por ciento). El promedio de duración del episodio causado por Shigella fue de 6.9/días; sin embargo, los pacientes tratados con antibióticos tuvieron un promedio de duración de 9.9 días y los pacientes sin antibióticos de 4.03 días, (p<0.0001). El 93,93 por ciento (28/30) de los pacientes que no recibieron antibióticos, 45,45 por ciento (10/22) de los episodios con monoterapia y 19,05 por ciento (4/21) de los casos con terapia combinada se resolvieron entre 1 y 7 días respectivamente (p=0.0018 y p<0.00001)