The instrumentation and practical circuitry required for the detection of negative ions exiting the mass analysis section of a mass spectrometer is examined. The potentials needed to bias the electron multiplier when detecting negative ions from a low ion-energy mass spectrometer, e.g., a quadrupole, are contrasted with the biasing requirements of a mass spectrometer having high ion-energies, e...

A nanocomposite membrane Cu2+ ion-selective electrode has been constructed using a new compound ethyl 1,2,3,4-tetrahydro-4-(4-methoxyphenyl)-6-methyl-2-oxopyrimidine-5-carboxylat (ETMOC) as a neutral ionophore. The electrode works properly. It responds to Cu2+ ion with a sensitivity of 29.5 ± 0.2 mV/decade over the range 1.0 × 10−9 to 5.0 × 10−1M at p...

For the analysis of trace amounts of hazardous organic compounds, we developed a new ion detection system for supersonic jet resonance-enhanced multiphoton laser ionization mass spectrometry. High sensitivity and selectivity have been achieved by combining a proto-type Daly detector, a newly designed conical ion lens, and a potential switch that can perform the function of a mass selector. This...

A new polyvinyl choloride (PVC) membrane sensor for cerium (III) was prepared based on 4,13-didecyl-1,7,10,16-tetraoxa-4,13-diazacyclooctadecane (kryptofix22DD) as an ionophore. The sensor exhibites a linear concentration range of 1.0×10-6to 1.0×10-1M, with a Nernstian slope of 18.0±1.0 mV/decade, and a detection limit of 9.7×10-7M. It has a fast response time (5 s) and can be used for two mont...

A simple, accurate and fast vortex-assisted dispersive liquid-liquid microextraction procedure has been developed for the extractive spectrophotometric determination of niflumic acid in biological samples. The method is based on the formation of an ion association complex between niflumic acid and methylene blue. The resulting ion-pair was extracted into dichloromethane and its absorbance was m...

In order to study the Cu(II) ion selective electrode, an optimized membrane was prepared by mixing of 30 mg of PVC powdered, 5 mg of considered ionophore, 60 mg of plasticizer and 5 mg of additive. The sensor showed a near Nernstian response for Cu(II) ions over a concentration range from 1.0×0-6 –1.0×0-2 M with a slope of 28.90.5 mV per concentration decade with a working pH range of 3.5-6.3. ...

A highly sensitive analytical method is required for the assessment of nanomolar perchlorate contamination in drinking water as an emerging environmental problem. We developed the novel approach based on a voltammetric ion-selective electrode to enable the electrochemical detection of "redox-inactive" perchlorate at a nanomolar level without its electrolysis. The perchlorate-selective electrode...

A method for direct and continuous detection of ion motion during different perturbation events of the fourier transform ion cyclotron resonance (FTICR) experiment is demonstrated. The modifications necessary to convert an ordinary FTICR cell into one capable of performing simultaneous excitation/detection (SED) using a capacitive network are outlined. With these modifications, a 200-fold reduc...