Source identification of PCBs in sediments from the Milwaukee Harbor Estuary, USA

1998 ◽  
Vol 37 (6-7) ◽  
pp. 199-206 ◽  
Author(s):  
P. Rachdawong ◽  
E. R. Christensen ◽  
S. Chi
Keyword(s):  
Principal Component Analysis ◽  
Mass Balance ◽  
Source Identification ◽  
Principal Component ◽  
Chemical Mass Balance ◽  
Pollutant Sources ◽  
First Time ◽  
Nonnegative Constraints ◽  
Good Agreement

This work focuses on the determination of PCB source profiles and their contributions to sediments in the Milwaukee Harbor Estuary by a principal component analysis (PCA) model. The model was recently developed and, for the first time, applied to apportion pollutant sources in sediments. Factor loadings and scores were computed, rotated via nonnegative constraints, and matched with candidate Aroclor profiles. Contamination by Aroclors 1016, 1242, 1254, and 1260 were identified for cores VC 6, 9, and 12 based on a log Q2 criterion. The majority of PCB contribution was from a combination of Aroclors 1016 and 1242. Similarity between Aroclors 1016 and 1242 obscured resolution between the two profiles. Results from a chemical mass balance (CMB) model with known Aroclor profiles were in good agreement with the prediction from the PCA model.

Determination of Agarwood oil’s significant chemical compounds using principal component analysis

2020 ◽  
Author(s):  
Mohamad Hushnie Haron ◽  
Mohd Nasir Taib ◽  
Nurlaila Ismail ◽  
Nor Azah Mohd Ali ◽  
Saiful Nizam Tajuddin
Keyword(s):  
Principal Component Analysis ◽  
Principal Component ◽  
Chemical Compounds ◽  
Component Analysis ◽  
Significant Chemical

scholarly journals ROCK MAGNETIC AND PALAEOMAGNETIC ANALYSES ON LITHIC FRAGMENTS FROM THE ARCHAEOLOGICAL SITE OF AKROTIRI, SANTORINI

2017 ◽  
Vol 50 (3) ◽  
pp. 1250
Author(s):  
E. Tema
Keyword(s):  
Principal Component Analysis ◽  
Deposition Temperature ◽  
Principal Component ◽  
Archaeological Site ◽  
Equilibrium Temperature ◽  
Component Analysis ◽  
Temperature Data ◽  
Minoan Eruption ◽  
Pumice Fall ◽  
Good Agreement

Rock magnetic and palaeomagnetic analyses on lithic clasts collected from the pumice fall deposited inside the archaeological site of Akrotiri have been applied in order to estimate the deposition temperature of the first volcanic products of the Minoan eruption. A total of 50 lithic clasts have been collected from four different locations inside the excavation of Akrotiri. All samples have been stepwise thermally demagnetized and the obtained results have been interpreted through principal component analysis. The equilibrium temperature obtained after the deposition of the pumice fall varies from sample to sample but generally shows temperatures around 240-280oC. These temperatures are in good agreement with those estimated from lithic clasts from the Megalochori Quarry while they are higher compared with those from ceramic fragments from Akrotiri. The new temperature data presented here show that the pumice fall was still relatively hot when deposited inside the archaeological site and even if it interacted with the buildings, often causing the collapse of roofs, it still remained hot with mean temperature around 260oC.

scholarly journals Explore the Effects of Fertilization on Polyphenols Content in Autumn of Forages from Hill Permanent Grassland by Principal Component & Classifications Analysis

2011 ◽  
Vol 68 (1) ◽  
Author(s):  
Monica HARMANESCU
Keyword(s):  
Colorimetric Method ◽  
Principal Component ◽  
Floristic Composition ◽  
Classification Analysis ◽  
Permanent Grassland ◽  
Different Types ◽  
The Matrix ◽  
Chemometric Techniques ◽  
First Time

Principal Components and Classification Analysis (PC&CA) represents one of the most utilised multivariate chemometric techniques, having the advantage to use many measurements for a single sample in the same time, being recommended for understanding better the complexity of one phenomenon. The aim of this paper was to use PC&CA to study the effects of different types of fertilizers on polyphenols content of forages harvested in autumn from permanent grassland. Gravimetrically was established the matrix of floristic composition. The experimental field was fertilized first time in 2003, organic and/or NPK mineral. The determination of polyphenols contents was made using UV-VIS SPECORD 205 spectrophotometer, in conformity to chemical Folin and Ciocalteu colorimetric method. The highest polyphenols content was identified in forages from unfertilized variant (108 µM gallic acid/g). PC&CA can be a useful tool in describing the modification of polyphenols contents of forages under the effects of organic and/or mineral fertilisation of permanent grassland.

Chemometric Approach to a Rapid Attenuated Total Reflection Fourier Transform Infrared Analysis of Complex Heroin-Based Mixtures

2020 ◽  
pp. 000370282096971
Author(s):  
Nataša Radosavljević Stevanović ◽  
Milena Jovanović ◽  
Federico Marini ◽  
Slavica Ražić
Keyword(s):  
Principal Component Analysis ◽  
Fourier Transform ◽  
Principal Component ◽  
Fourier Transform Infrared ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Illegal Market ◽  
Ft Ir

Heroin is one of the most frequently seized drugs in Southeastern Europe. Due to the position in the Balkan route, the Republic of Serbia keeps important role in suppression of the trafficking of heroin for domestic and foreign illegal market. This research is aimed to provide a good scientific approach in the field of seized heroin analysis. Two different forms of heroin are present in the illegal market, mostly in mixtures with typical “cutting” agents: caffeine, paracetamol, and sugars. It was observed that the quantity of pure heroin in seized samples slightly increases from year to year. The aim of this study was to produce a reliable and fast procedure for classification of illicit heroin samples and determination of the concentration range of heroin in the samples. For that purpose, the attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR) technique was used and combined with such chemometric methods as principal component analysis, cluster analysis, and partial least squares. Principal component analysis (PCA) as an unsupervised model was used for exploratory purposes to identify trends, similarities, and differences between samples by reducing the dimensionality of the data. The cluster classification of examined samples turned out to be extremely useful to evaluate the possibilities of the ATR FT-IR technique to classify the samples appropriately into the patterns, the constituted clusters. Additionally, partial least square was the suitable method for the purpose of determination of the heroin hydrochloride concentration range in examined samples. It is proved that the joined application of spectroscopy and chemometrics can be extremely convenient and useful for forensic and drugs control laboratories.

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