Identification of iron ore brands by multi-component analysis and chemometric tools

Author(s):  
Chenglin Yan ◽  
Zhixiu Zhu ◽  
Xiaohong Wu ◽  
Bo Zhang ◽  
Wenya Zhao ◽  
...  
Author(s):  
Chenglin Yan ◽  
Zhixiu Zhu ◽  
Xiaohong Wu ◽  
Bo Zhang ◽  
Wenya Zhao ◽  
...  

2016 ◽  
Vol 99 (5) ◽  
pp. 1279-1286 ◽  
Author(s):  
Vanessa Giannetti ◽  
Maurizio Boccacci Mariani ◽  
Paola Mannino

Abstract An authentication study based on headspace solid-phase microextraction/GC-MS was performed with a set of 60 samples representative of traditional “Pasta di Gragnano protected geographical indication (PGI)” and the most common Italian pasta brands. Multivariate chemometric tools were used to classify the samples based on the chemical information provided from 20 target flavor compounds, including Maillard reaction and lipid oxidation products. Pattern recognition by principal component analysis and linear discriminant analysis showed a natural grouping of samples according to the drying process adopted for their production (i.e., the traditional Cirillo method versus a high-temperature approach). Subsequently, soft independent modeling by class analogy (SIMCA) and unequal dispersed classes (UNEQ) were used to build class models at 95% confidence and 100% sensitivity levels (forced models) for predictive classification purposes. The good performance obtained from the models in terms of cross-validation efficiency (SIMCA, 57.01%; UNEQ, 86.60%; 100% for both forced models) highlighted that targeted analysis of flavor profiles could be used to assess the authenticity of Pasta di Gragnano PGI samples. Hence, the proposed method may help to protect Pasta di Gragnano PGI from label frauds by verifying whether samples comply with statements concerning drying process conditions as stated in the product specification.


2010 ◽  
Vol 66 ◽  
pp. 29-34 ◽  
Author(s):  
Virginia Martina ◽  
M. Federica de Riccardis ◽  
Daniela Carbone

Poly(etherether-ketone) (PEEK) suspensions in ethanol and isopropanol containing also α-alumina and hydroxyapatite powders were studied. An innovative method was used in the study of the quality of suspensions. We studied suspensions by means of zeta potential and grain-size measurements. The comparison amongst the different suspensions was carried out by using statistical and chemometric tools, especially by the use of an explorative test based on the Principal Component Analysis (PCA). The chemometric analysis was performed by involving different combinations of each type of powder and each type of solvent.


VASA ◽  
2012 ◽  
Vol 41 (5) ◽  
pp. 333-342 ◽  
Author(s):  
Kirchberger ◽  
Finger ◽  
Müller-Bühl

Background: The Intermittent Claudication Questionnaire (ICQ) is a short questionnaire for the assessment of health-related quality of life (HRQOL) in patients with intermittent claudication (IC). The objective of this study was to translate the ICQ into German and to investigate the psychometric properties of the German ICQ version in patients with IC. Patients and methods: The original English version was translated using a forward-backward method. The resulting German version was reviewed by the author of the original version and an experienced clinician. Finally, it was tested for clarity with 5 German patients with IC. A sample of 81 patients were administered the German ICQ. The sample consisted of 58.0 % male patients with a median age of 71 years and a median IC duration of 36 months. Test of feasibility included completeness of questionnaires, completion time, and ratings of clarity, length and relevance. Reliability was assessed through a retest in 13 patients at 14 days, and analysis of Cronbach’s alpha for internal consistency. Construct validity was investigated using principal component analysis. Concurrent validity was assessed by correlating the ICQ scores with the Short Form 36 Health Survey (SF-36) as well as clinical measures. Results: The ICQ was completely filled in by 73 subjects (90.1 %) with an average completion time of 6.3 minutes. Cronbach’s alpha coefficient reached 0.75. Intra-class correlation for test-retest reliability was r = 0.88. Principal component analysis resulted in a 3 factor solution. The first factor explained 51.5 of the total variation and all items had loadings of at least 0.65 on it. The ICQ was significantly associated with the SF-36 and treadmill-walking distances whereas no association was found for resting ABPI. Conclusions: The German version of the ICQ demonstrated good feasibility, satisfactory reliability and good validity. Responsiveness should be investigated in further validation studies.


2000 ◽  
Vol 3 ◽  
pp. np
Author(s):  
Keith S. Dobson ◽  
Paula A. Truax ◽  
Michael E. Addis ◽  
Kelly Koerner ◽  
Jackie K. Gollan ◽  
...  

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