325 research outputs found
Peculiar and Unusual Drowning in Waste Oil from Motor Vehicles: Case Report
Drowning is one of the most frequent causes of accidental or suicidal death, and more rarely it is associated with
a homicide. Cases of drowning in water or in the sea are common. The authors report an unusual and peculiar case
of drowning, that of a woman who accidentally fell inside a collection tank of waste oil of motor vehicles
Analysis of native carotenoid composition of sweet bell peppers by serially coupled C30 columns.
Serial coupled columns reversed-phase separations in high-performance liquid chromatography can be a useful tool for the analysis of complex real samples. The great difficulties found when analyzing complex carotenoid samples, due to the high natural variability of these compounds, as well as to the presence of carotenoid esters, are well documented. In the present contribution, the applicability of connecting two C30 columns to increase significantly the separation power, resolution and peak capacity for the analysis of carotenoids in a complex carotenoid sample, like sweet bell peppers, has been shown for the first time. By using LC coupled to PDA/APCI-MS detectors, 56 different carotenoids have been detected in red sweet bell peppers. By using two serial coupled C30 columns a peak capacity of 95.4 was obtained, compared with 73 achieved using a single column. Moreover, resolution greatly improved between different critical peaks when using two serial coupled C30 columns, compared with a single column. Interestingly, free carotenoids, mono-esters and diesters were quantitatively equally represented (around 33% for each different class) in red sweet bell pepper, showing, therefore, a value for the ratio of mono-esters/di-esters of around 1, which could be considered a parameter of typicality. Free β-carotene (12.6%), capsanthin-C14:0 (8.4%), and capsanthin-C12:0-C14:0 (8.9%) were the most abundant carotenoids in the three different classes of red sweet bell pepper. No carotenoid esters were detected in either yellow or green sweet bell peppers. The application of such methodology in the analysis of other complex carotenoid matrices could be a future objective of research
Determination of bioactive compounds in the juice of pummelo (Citrus grandis Osbeck).
The juice of pummelo (Citrus grandis Osbeck) was analyzed to determine its composition of flavonoids, polymethoxyflavones, coumarins and psoralens. The analyses were carried out by HPLC using columns packed with small diameter Fused-Core® C18 particles to achieve high resolution in short analysis time. In addition, the profile of the native carotenoids present in the juice was determined using a C30 column. Identification of flavonoids was achieved by MS with ESI in negative mode; the MS acquisition of oxygenated heterocyclic compounds was performed in positive APCI; carotenoids were detected with a PDA detector. Nineteen native carotenoids were determined in pummelo juice for the first time. The composition of this juice is also discussed in comparison with other Citrus juices, especially grapefruit
Immunohistochemical detection of early myocardial infarction: a systematic review
The postmortem diagnosis of early myocardial infarction is a challenge for forensic pathologists because the routine histology is neither specific. Many authors have suggested the use of the immunohistochemistry to fill the gaps in the histological diagnosis of early myocardial infarction. This review aims to analyse advances of immunohistochemical detection of early cardiac damage due to ischaemia. To this purpose, we reviewed experimental studies that investigated immunohistochemical markers and their estimated timing of expression. The review was performed according to specific inclusion and exclusion criteria, and a total of 23 studies assessing the immunohistochemical markers for the diagnosis and timing of early myocardial infarction were identified. The literature review highlights that the analysed markers are complement components, others being inflammatory mediators, cardiac cell proteins, plasma proteins, stress or hypoxia-induced factors and proteins associated with heart failure. All studies demonstrate the effectiveness of the tested markers in the early detection of myocardial infarction in both animal and human samples
Quantitative and physical evaluation of patchouli essential oils obtained from different sources of Pogostemon cablin.
Patchouli essential oil can be obtained from fresh, dried and fermented plant material. It is a highly valuable product in the fragrance industry and its quality changes depending upon raw material age and oil storage. In this work, patchouli essential oils derived from different treatments have been subjected to GC-FID quantitative analysis using an internal standard (ISTD) method with response factors (RF). Samples were obtained from i) fresh plants; ii) hydrodistillation of one year mature and fermented plants; iii) hydrodistillation of one year mature plants; iv) commercial products from Indonesia and Malaysia. Linear Retention Indices (LRI) for both polar and non-polar GC-MS analyses were also measured as a tool for qualitative analysis towards a homologous series of C7-C30 n-alkanes. The results obtained confirmed that, in all samples, patchouli alcohol was the main volatile constituent, with higher amount in lab-scale produced oils, compared with commercial samples. Other major compounds, in lab oils and commercial samples respectively, were: δ-guaiene, α-guaiene, pogostol, seychellene and α-patchoulene. Another 36 compounds were also found
Sudden death in water: Diagnostic challenges
The authors report a case of sudden death in a breath-holding diver and highlight the forensic diagnostic difficulties in opining the cause of sudden death in water. The autopsy showed increased thickness of the left ventricular wall with a distinct pattern of concentric hypertrophy, evident particularly in the subaortic interventricular septum. Histological examination revealed diffuse interstitial fibrosis and associated findings of multifocal myocyte disarray especially evident in the subaortic interventricular septum. The analysis and discussion of this case made it possible to attribute sudden death to a lethal arrhythmia following myocyte disarray and hypoxia caused by breath-holding, the triggering factor of apnea. This case demonstrates the importance of a thorough forensic investigation, particularly in histological terms, in subjects found dead in water, in order to ascertain the real cause of death, which may not be always ascribable to drowning
Micro-bore Column Fast Gas Chromatography-Mass Spectrometry in Essential Oil Analysis:
The present research is focused on the use of micro-bore column fast gas chromatography in combination with rapid-scanning quadrupole mass spectrometry for mediumly-complex essential oil analysis. A basil essential oil sample was initially subjected to conventional GC-MS (analysis time: 25 min) under optimum analytical conditions. Peak identification was carried by using a dual-filtered MS library search procedure: the first filter deleted "hits" with a less than 90% spectral similarity, while the second filter eliminated matches with a linear retention index (LRI) outside a pre-defined LRI window. The same essential oil sample was analyzed under optimized fast GC-MS conditions by using a micro-bore column, with the same aforementioned MS library search process (analysis time: 5.3 min). Resolution was altogether similar in both applications, with the same number of compounds reliably-identified, namely fifty-nine. The experiment demonstrated the usefulness of the rapid GC approach in this type of experiment
Linear retention index approach applied to liquid chromatography coupled to PDA and QqQ MS detectors for reliable characterization of oxygen heterocyclic compounds in essential oils and finished cosmetic products
Regulation (EC) n.1223/2009 of the European Parliament includes furocoumarins (FC) in the list of substances prohibited in cosmetic products except for normal content in natural essences used, the limit in sun protection and bronzing products is 1 mg/Kg [1]. Despite the official regulations the Scientific Committee on Consumers Products (ISCC) and the International Fragrance Association (IFRA) are still proposing the maximum content of psoralens in rinse-off and leave-on products, according to the latest evidences of phototoxicity [2,3]. To date, LC coupled to PDA detector is the main technique employed for FC determination. However, the high Limits of Quantification (LOQs) suggested by IFRA, limit the HPLC-PDA application to the analysis of essential oils, making necessary the development of a more sensitive HPLC-MS method for the analysis of FC at trace level in the finished cosmetic products [4]. This work provides a detailed analysis of PDA LOQs calculated for several oxygen heterocyclic compounds, among FC, coumarins, and polymethoxyflavones. The linear retention index approach was used, for the first time, together with the UV library, as an extra criterion for the reliable characterization of the target compounds in the essential oils. The LRI of specific volatile compounds were calculated in order to identify the interfering compounds of the matrix which affect the LOQs. Calibration curves were created in pure solvent and by adding the standard compounds to different blank samples, with the aim to overcome the matrix effect. Moreover, LRI was applied to a new more sensitive HPLC-QqQ MS method, with MS and MS/MS (Multiple Reaction Monitoring) libraries and external calibration. The MS method was validated and used to determine the content of FC in cosmetics, such as perfumes and body wash
Volatiles from steam-distilled leaves of some plant species from Madagascar and New Zealand and evaluation of their biological activity.
Steam-distilled aerial parts of Ravensara Aromatica and Cinnamomum camphora from Madagascar and Leptospermum scoparium from New Zealand have been subjected to qualitative and quantitative analysis by means of GC techniques. This allowed the elucidation of conflicting data present in the available literature for these species. Also, the biological activity in vitro was evaluated by measuring MICs and GIZs
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