Bogen and Welford (1971) obtained good results using LSC for total beta and alpha assay. Ludwick (1960) applied LSC to beta counting of 24!pu. Price (1972) reports that he obtained 100% counting efficiency for 239py, 24 1am, 244om and 92% for 237Np using a TTWC liquid scintillating gel. McDowell et al, (1974) have reported on the use of a combined solvent extract ion-liquid scintillation method for Pu and U determination in environmental samples. Alpha counting efficiencies of 100% and an energy resolution of 260 to 300% keV are quoted. Scintillations produced by Pu alpha particles on a ZnS screen, coupled to a photomultiplier, are reported by Hallden and Harley (1960), Kooi and Holistein (1962). An extensively applied method for ?“!am is to detect the 60-KeV gamma in a NaI(T1) scintillation well counter as described by Bubernak et al. (1956), Cline (1967), Filer (1974), and Wallace (1972). Numerous other detector and sample counting geometries have been discussed, including a thin NaI(Tl) wafer detector and plastic jar containing dissolved soil solutions, 10 g per 100 g of solution, as reported by Major et al. (1974), on the use of a solid state planar germanium detector for 10-g soil samples as given by Essington et al. (1976). Heimbuch and Gee (1962) developed a scintillating ion exchange resin which they applied to the assay of plutonium. Gee et al. (1967) used Alpha-a-Cal, an acetate base backed with a 2-3 mg/cm? ZnS, to enchance registration of Am alpha particles on film with several orders of magnitude increase in sensitivity. Schwendiman and Healy (1958), Campbell and Moss (1963), and Everett et al. (1964) all describe the use of nuclear track plates for high sensitivity measurements of Pu in urine. Isotope dilution surface ionization mass spectrometry has been applied to environmental samples as low as 0.006 dpm by Dupzyk et al. (1972) measuring 239pu, 240py, and 24!pu with 242pu tracer. Hoffman et al. (1971) used a similar technique to detect ?""Pu in nature. Noshkin et al. (1974) used 235np tracer and mass spectrometry to measure *3’Np in sediment samples. Exposure to neutrons in a reactor and the search for activation or fission products or tracks have also been used, Larson and Oldham (1974a), to provide highly sensitive analysis of the actinides. Some of the early instrumental techniques are those of Jacobson and Overstreet (1948) in which he used a linear amplifer system co assay 739Pu. SUMMARY There are numerous procedures for the analysis of transuraniums (TU) in environmental samples, and in environmental type samples from laboratory or field studies. There are many variations on reported methods and so many ways to achieve the final result accurately that none can be singled out as the preferred method. Ie is known, also, that in actual laboratory operation, there are deviations from published procedures due to sample variations and procedure improvements and publication lag. Also, the accuracy and precision of the final data is known to be much dependent upon individual experience, competence, and quality control. Possibly, the driving force for continual changes, besides scientific inquiry, is to minimize analysis costs. By their very nature, sensitive TU analysis costs have always been expensive. A comparison of available 1976-cost data to that of 1963 Roller Coaster Project costs was made. Analysis for 239py in 10 g of soil is now being performed with lower labor cost, and slightly reduced material costs. The net overall cost is slightly lower. For small filter samples, labor is lower, material higher, and the net change is to a slightly higher cost. Both cost figures show significant procedure and operational cost reductions have been well ahead of the 13-year span of inflation. Cost figures at other facilities are not available but they would also be influenced by changes in overall technology at that facility. Possibly, a laboratory performing gross analyses in 1963 would have expertenced a significant rise in costs in converting to isotope dilution analyses, exclusive of equipment costs. Presently there is a wealth of procedures available for Pu and Am, although not for Np and Cm. There is progress in sensitivity, accuracy, and cost reduction. Relative to the use of TU analyses as a tool in various studies and as a regulatory requirement, it is expected there will continue to be a need for procedure improvement studies. Rhodes (1957) studied the absorption of Pu in soil with a parallel plate alpha counter. Buenger et al. (1962) detected Pu alphas by a 2 7 proportional counter. Sill and Williams (1971) used surface barrier detectors for direct alpha spectrometry of environmental samples. Melgard et al. (1968) preferred Frisch grid chambers to surface barrier detectors because of buildup of daughter product contamination from samples was not permanent and uniformity of plates was not required. Development of the multichannel analyzers and the associated data acquisition systems has made APHA by either surface barrier or Frisch grid chambers the preferred method for environmental alpha counting. 565 564