This report was prepared for the Commission by Professor A. J. B. Robertson. Particular attention was paid to definitions already proposed by the Fachnormenausschuss Vakuumtechnik in Deutschen Normenausschuss and in the Editorial Review on Nomenclature in Organic Mass Spectrometry,2, 249(1969).

Recent developments in the field of mass spectrometry taking place at the Caltech Jet Propulsion Laboratory are highlighted. The pertinent research and development is aimed at producing an ultrahigh sensitivity mass spectrograph for both spaceflight and terrestrial applications. The unique aspect of the JPL developed technology is an integrating focal plane ion detector that obviates the need for spectral scanning since all ions over a wide mass range are monitored simultaneously. The ion detector utilizes electro-optical technology and is therefore referred to as an Electro-Optical Ion Detector (EOID). A technical description of the JPL MS/EOID, some of the current applications, and its potential benefits for internal contamination analysis are discussed.

Mass spectra have been measured for single aerosol particles in the micron size range on a continuous, real-time basis. Particle beams of dioctyl phthalate, glutaric acid, adipic acid, ammonium sulfate, and some of the amino acids were generated by expansion of these aerosols through a capillary nozzle (throat diameter = 0.1 mm and length = 5 mm) and a skimmer (diameter = 0.331 mm). The transmission efficiency of the beam generator has been measured for different particle sizes. Individual particles were volatilized by impaction on a hot rhenium V-type filament (300 to 1400°C) and the resulting vapor plume ionized by electron bombardment in the ionizer of a quadrupole mass spectrometer. Ion currents for different masses from individual particles have been measured. The intensity of the characteristic mass peaks of different size aerosol particles increased linearly with their volume. Ammonium sulfate aerosols produce signals at SO+, SO2+, SO3+ mass fragments whereas no SO3+ mass peak could be detected from sodium sulfite particles. The absence of SO3+ from sulfite can be used to differentiate between the sulfate/sulfite contents of aerosol particles.

A number of cell surface molecules of great theoretical and practical importance simply cannot be obtained in amounts sufficient for molecular analysis using conventional methods and instrumentation. Because of our interest in such studies, we began about eight years ago to explore the possibility of developing new instrumentation for the sequence analysis of very small quantities of polypeptide chains. These efforts have led to the development of two microsequenators which employ one thousandth to one ten-thousandth the material used in the original sequenator described by Per Edman. In addition, in conjunction with the explosion of recombinant DNA techniques, we also have begun to develop instrumentation for the sequence analysis and synthesis of DNA molecules. In this paper we describe briefly several new instruments that have been developed at Caltech. We believe this new instrumentation in conjunction with the recombinant DNA and hybridoma technologies will provide unique opportunities to analyze cell-surface molecule in the years ahead.

System performs rapid multiple analyses of entire compound classes or individual compounds on small amounts of sample and reagent. Method will allow screening of large populations for metabolic disorders and establishment of effective-but-safe levels of therapeutic drugs in body fluids and tissues.

Today's mass spectrometers provide data to the researcher in two modes: (1) in the form of a photographic plate where line densities provide integrated ion abundances, and (2) in the form of a strip chart recording where peak intensities provide ion abundances during a mass versus time scan. Both types of data suffer from low sensitivity - the former due to the insensitivity of photographic emulsions to positive ions (104 ions required for a detectable line) and the latter from a low duty cycle due to spectral scanning (typically 10-2 - 10-4). This paper describes the development of an electro-optical ion detector combining the best features of photographic and electrical ion detection (i.e., wide mass range coverage and low ion detection threshold respectively). A nineteen fold fiber optic image dissector is discussed which reformats the 1 mm x 361 mm mass spectrometer focal plane format to a 19 mm x 19 mm format suitable for vidicon imaging and electronic display of the data.

Abstract A mass spectrograph, coupled to automatic sample preparation devices and an electro-optical ion detector/ computer system, capable of detecting many ion species simultaneously, presents a promising new approach to biomedical analysis. It will permit simultaneous multicomponent analysis of appropriately prepared samples and may detect as little as 10-15 g of a single component. This approach offers significant advantages over other methods, including conventional mass spectrometry.

An electro—optical ion detector for a Mattauch—Herzog focal plane mass spectrometer is described. The detector consists of a channel electron multiplier array, phosphor screen, fiber optic image dissector and vidicon camera system. Experimental verification of the concept is discussed with particular attention given to intense stray magnetic fields, resolving power, sensitivity and channel electron multiplier array geometry.

The design and fabrication of a completely portable, self-contained gas chromatograph is described. This instrument utilizes a closed-loop hydrogen carrier gas flow as maintained by a hydrogen generator-separator. It employs an auxiliary hydrogen generator to keep a positive flow of hydrogen through the detector. The detector is an ionization cross section detector. The only maintenance required is the addition of water (5–15 cc/day) to the auxiliary hydrogen generator. Lower limit of detection for the present system is of the order of 1–10 ppm ethane.