Paper spray mass spectrometry is a method for the direct analysis of biofluid samples in which extraction of analytes from dried biofluid spots and electrospray ionization occur from the paper on which the dried sample is stored. We examined matrix effects in the analysis of small molecule drugs from urine, plasma, and whole blood. The general method was to spike stable isotope labeled analogs of each analyte into the spray solvent, while the analyte itself was in the dried biofluid. Intensity of the labeled analog is proportional to ionization efficiency, whereas the ratio of the analyte intensity to the labeled analog in the spray solvent is proportional to recovery. Ion suppression and recovery were found to be compound- and matrix-dependent. Highest levels of ion suppression were obtained for poor ionizers (e.g., analytes lacking basic aliphatic amine groups) in urine and approached –90%. Ion suppression was much lower or even absent for good ionizers (analytes with aliphatic amines) in dried blood spots. Recovery was generally highest in urine and lowest in blood. We also examined the effect of two experimental parameters on ion suppression and recovery: the spray solvent and the sample position (how far away from the paper tip the dried sample was spotted). Finally, the change in ion suppression and analyte elution as a function of time was examined by carrying out a paper spray analysis of dried plasma spots for 5 min by continually replenishing the spray solvent.
A method is presented for the direct quantitative analysis of therapeutic drugs from dried blood spot samples by mass spectrometry.
The method, paper spray mass spectrometry, generates gas phase ions directly from the blood card paper used to store dried
blood samples without the need for complex sample preparation and separation; the entire time for preparation and analysis
of blood samples is around 30 s. Limits of detection were investigated for a chemically diverse set of some 15 therapeutic
drugs; hydrophobic and weakly basic drugs, such as sunitinib, citalopram, and verapamil, were found to be routinely detectable
at approximately 1 ng/mL. Samples were prepared by addition of the drug to whole blood. Drug concentrations were measured
quantitatively over several orders of magnitude, with accuracies within 10% of the expected value and relative standard deviation
(RSD) of around 10% by prespotting an internal standard solution onto the paper prior to application of the blood sample.
We have demonstrated that paper spray mass spectrometry can be used to quantitatively measure drug concentrations over the
entire therapeutic range for a wide variety of drugs. The high quality analytical data obtained indicate that the technique
may be a viable option for therapeutic drug monitoring. 相似文献
Mass spectral analysis was carried out on shellfish samples taken in the vicinity of the Arrow oil spill at Chedabucto Bay, Nova Scotia. Oil samples were also analyzed, samples being obtained from the tanker and also from the beach. After extraction of the oil and shellfish samples, group separations were made into aliphatic, aromatic and oxygenated fractions, which were analyzed separately by mass spectrometry. The validity of the group separations was established, since, in the analysis of the so-called aliphatic fraction, no evidence of aromatics could be seen by mass spectrometry. On the other hand, polycyclic hydrocarbons were found in some of the aromatic fractions. Identification was based upon standard mass spectrometric analysis already performed on known examples of the polycyclics. It was concluded that the possibility of oil contamination can be confirmed by the mass spectrometric analysis of appropriate samples. It was also concluded that the so-called control samples should have been taken at a greater distance from the oil spill. 相似文献
Abstract Several recent reports indicate that both toxaphene (polychlorocamphene, PCC) and chlordane are widespread pollutants in our environment. These insecticides, both complex mixtures of chlorinated hydrocarbons, are difficult to separate from each other. Thus the analyses of them in environmental samples are difficult and furthermore complicated by interferences from other chlorinated hydrocarbons such as PCB and DDT compounds. Mass fragmentography using the negative ions formed by chemical ionization proved to be useful to selectively detect the toxaphenes and the chlordanes without interferences from DDT. High concentrations of PCB still influence on the results and have to be removed in the clean-up procedure. 相似文献
Surface modification of polymers by low-pressure plasmas has gained scientific and industrial importance for controlling adhesion of coatings, wettability, printability, bio-compatibility and other surface-related properties. However, more is to be learned about the complex interactions at the plasma-polymer interface. The present study is designed to investigate these plasma-polymer surface interactions by means of mass spectrometry. Various polymer specimens (polyethylene, polypropylene, polyethylene terephthalate, and polyimide) were placed directly on an electrode which contains the sampling aperture into a quadrupole mass spectrometer. We have identified various molecular fragments from these polymers, which were liberated by chain scissions provoked by various energetic plasma constituents, in particular, bombarding ions and vacuum ultraviolet (VUV) photons. 相似文献
Direct analysis of plant and animal tissue samples by laser electrospray mass spectrometry (LEMS) was investigated using low-energy, femtosecond duration laser vaporization at wavelengths of 800 and 1042 nm followed by nanospray postionization. Low-energy (<50 μJ), fiber-based 1042 nm LEMS (F-LEMS) allowed interrogation of the molecular species in fresh flower petal and leaf samples using 435 fs, 10 Hz bursts of 20 pulses from a Ytterbium-doped fiber laser and revealed comparable results to high energy (75–1120 μJ), 45 fs, 800 nm Ti:Sapphire-based LEMS (Ti:Sapphire-LEMS) measurements. Anthocyanins, sugars, and other metabolites were successfully detected and revealed the anticipated metabolite profile for the petal and leaf samples. Phospholipids, especially phosphatidylcholine, were identified from a fresh mouse brain section sample using Ti:Sapphire-LEMS without the application of matrix. These lipid features were suppressed in both the fiber-based and Ti:Sapphire-based LEMS measurements when the brain sample was prepared using the optimal cutting temperature compounds that are commonly used in animal tissue cryosections.
Chromatographia - Liquid chromatography–mass spectrometry (LC–MS) technique has been widely used for the determination of trace carbohydrate compounds in biological samples. However,... 相似文献
