Search results for "Trap"
showing 10 items of 2144 documents
Direct Peel Monitoring of Xenobiotics in Fruit by Direct Analysis in Real Time Coupled to a Linear Quadrupole Ion Trap–Orbitrap Mass Spectrometer
2013
Study of xenobiotics present in fruit peel by exposing it (without any pretreatment) to direct analysis in real time coupled to a high-resolution orbitrap mass spectrometer (DART-HRMS) is reported for the first time. Variables such as DART gas heater temperature and pressure, source-to-MS distance, and sample velocity are investigated. The analysis of one sample by DART-MS lasts ca. 1 min, and the benefits of both high-resolution and tandem mass spectrometry to elucidate nontarget or unknown compounds are combined. Identification of postharvest fungicides, antioxidants, and sugars in fruit peel is performed in the positive ion mode. A possible elemental formula is suggested for marker compo…
Bibliotēkas pārvaldes sistēma
2021
Kvalifikācijas darba “Bibliotēkas pārvaldes sistēma” galvenais mērķis ir aprakstīt un izstrādāt sistēmu, kas palīdzētu daļēji digitalizēt bibliotēkas pārvaldes funkcionalitāti un nodrošinātu iespēju attālināti pārskatīt bibliotēkā pieejamos resursus. “Bibliotēkas pārvaldes sistēma” ir tiešsaistē pieejama sistēma, kas ļauj bibliotekāriem pārvaldīt grāmatu klāstu bibliotēkā un novērot veiktās rezervācijas. Ikdienas lietotāji var pārskatīt bibliotēkā pieejamās grāmatas un veikt šo grāmatu rezervāciju, kas nodrošina resursa pieejamību konkrētam lietotājam, ja uzreiz fiziski paņemt to nav iespējams. Lietotājs var brīvi uzzināt informāciju par grāmatu žanriem un autoriem, kā arī pārskatīt iepriek…
"Bankett"-banketu zāļu un svētku pakalpojumu katalogs, galvenais palīgs pasākumu organizēšanā Rīgā
2018
Kvalifikācijas darba mērķis ir izstrādāt sistēmu priekš pasākumu organizēšanas. Sistēma ļauj organizēt banketus Rīgā ātri un kvalitatīvi, tāpēc ka sistēmā atrodas visu izlaides sfēru pārstāvji. Pateicoties ērtai saskarnei ir ērti atrast nepieciešamo pakalpojumu. Lietotāji var iepazīties ar interesantām ziņām, kas satur padomus priekš labu pasākumu organizēšanas. Sistēma domāta gan lietotājiem, kuri grib atrast pakalpojumu savam pasākumam, gan lietotājiem, kas grib piedāvāt citiem savus pakalpojumus, kā arī administratoriem, kuri pārvalda sistēmu.
Transportlīdzekļu nomas un pārvaldes sistēma
2019
Informācijas sistēma “Transportlīdzekļu nomas un pārvaldes sistēma” ir publiska tiešsaistes sistēma, kas sniedz iespēju digitalizēt transportlīdzekļu pārvaldi, kā arī ieviest transportlīdzekļu nomas iespējas attālināti. Sistēma ļauj elektroniski iesniegt transportlīdzekļu nomas pieteikumus lietotājiem un pārvaldīt transportlīdzekļu nomas un pieteikumus atbildīgajām personām. Sistēmas lietotāji transportlīdzekļu nomas pieteikuma iesniegšanas brīdī veic apmaksu, kas padara nomas procesu daudz pārskatāmāku un drošāku pakalpojuma sniedzējiem. Sistēmā ietvertā transportlīdzekļu meklēšanas funkcija ļauj lietotājiem ērtāk un pārskatāmāk atrast sev vēlamo vai konkrētajā laikā pieejamo transportlīdz…
Latinoamérica y Vargas Llosa / 2
2006
X-ray crystal structure and antimony-121 Mössbauer spectrum of catecholato bis(1,10-phenanthroline)antimony(III) tetraphenylborate
1985
The crystal structure of the title compound was solved by means of X-ray diffraction at room temperature. The salt consists of a tetrahedral tetraphenylborate anion and a complex cation containing a catecholatoantimony(III) unit chelated by two 1,10-phenanthrolines. The three bidentate ligands are essentially arranged in one half of the Sb coordination sphere, leaving ample space to accomodate the lone pair of electrons. The Mossbauer parameters of the title compound and of the complex (C6H4O2)SbF·Phen were measured and their rationalization accomplished in the light of their respective molecular structures.
Ultrahigh-Resolution Mass Spectrometry in Real Time: Atmospheric Pressure Chemical Ionization Orbitrap Mass Spectrometry of Atmospheric Organic Aeros…
2018
The accurate and precise mass spectrometric measurement of organic compounds in atmospheric aerosol particles is a challenging task that requires analytical developments and adaptations of existing techniques for the atmospheric application. Here we describe the development and characterization of an atmospheric pressure chemical ionization Orbitrap mass spectrometer (APCI-Orbitrap-MS) for the measurement of organic aerosol in real time. APCI is a well-known ionization technique, featuring minimal fragmentation and matrix dependencies, and allows rapid alternation between the positive and negative ionization mode. As a proof of principle, we report ambient organic aerosol composition in rea…
Optimization of a microwave-assisted extraction large-volume injection and gas chromatography–ion trap mass spectrometry procedure for the determinat…
2006
Abstract A sensitive and rapid method for the determination of polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs) and polychlorinated naphthalenes (PCNs) in sediment samples is proposed. The method involving microwave-assisted extraction (MAE) and large-volume injection (LVI) gas chromatography (GC)–ion trap mass spectrometry (ITMS), and the experimental conditions were optimized using the statistical design of experiments (DOE). A Plackett–Burman (P–B) design was chosen to estimate the influence of five factors, such as resonance excitation voltage (EV), isolation time (IT), excitation time (ET), ion source temperature (IST) and electron energy (EE) on the analytical r…
Multiple-stage mass spectrometric analysis of six pesticides in oranges by liquid chromatography–atmospheric pressure chemical ionization–ion trap ma…
2004
Abstract Six pesticides were determined by liquid chromatography (LC) with positive ion (PI) atmospheric pressure chemical ionization quadrupole ion-trap tandem mass spectrometry (APCI–MS–MS). Ion fragmentation was studied by MS, MS 2 and MS 3 . Fragmentation of the pesticides produced ions formed by various losses from the side-chains and through heterocyclic ring opening, but without any common fragmentation pathway. Multiple reaction monitoring (MRM) of MS, MS 2 and MS 3 was used to identify and quantify the pesticides. The samples were extracted with ethyl acetate and dried over anhydrous sodium sulfate. Comparison of the three MS modes showed that MS 3 is slightly less sensitive but mu…
Solid-Phase Microextraction Liquid Chromatography/Tandem Mass Spectrometry To Determine Postharvest Fungicides in Fruits
2003
A method to determine five postharvest fungicides (dichloran, flutriafol, o-phenylphenol, prochloraz, tolclofos methyl) in fruits (cherries, lemons, oranges, peaches) has been developed using solid-phase microextraction (SPME) coupled to liquid chromatography (LC) with photodiode array (DAD), mass spectrometry (MS), or tandem mass spectrometry (MS/MS) with ion trap detection. Extraction involved sample homogenization with an acetone/water solution (5:1), filtration, and acetone evaporation prior to fiber extraction. The pesticides were isolated with a fused-silica fiber coated with 50-microm Carbowax/template resin. The effects of pH, ion strength, sample volume, and extraction time were in…