Search

A gas chromatographic method was developed for the quantification of alkylmercury species using microwave-induced plasma atomic emission detection (GC-AED). The column conditioning and analyte derivatization required for previous methods were found to be unnecessary for stable, accurate, and sensitive element-specific detection using GC-AED. Chromatographic and detection parameters such as stationary phase type, stationary phase film thickness, GC column dimensions, helium mobile phase column head pressure, detector makeup gas flow rate, and detector reagent gas type and flow rate were found to significantly affect analyte response. The detection limit for the optimized GC-AED conditions was 0.8 pg (0.1 pg/s) of methylmercury chloride (as mercury). A solid-liquid extraction procedure with preparative gel permeation chromatography cleanup and GC-AED analysis was used to quantify methylmercury in a variety of complex matrix marine materials. The methylmercury quantification method was validated with four marine certified reference materials (CRMs). The method was then applied to 13 standard reference materials, CRMs, and control materials for which no certified reference values for methylmercury have been determined. Four National Institute of Standards and Technology Standard Reference Materials and one control material, which were analyzed using the GC-AED method, were also analyzed by two other laboratories using independent methods to further validate the method.

Three laboratories participated in an interlaboratory comparison exercise for the determination of polychlorinated biphenyl (PCB) congeners and chlorinated pesticides in Standard Reference Material (SRM) 1588 (Organics in Cod Liver Oil) a whale blubber control material, and six beluga whale (Delphinapterus leucas) blubber samples. The results are generally in good agreement. The minor disagreement of some of the results may be attributed to differences in detector calibrations, differences in chromatographic separation selectivity for specific compounds, or both. The SRM and control material help to validate the analytical procedures and to verify that these procedures remain in control.

Concentrations for 38 elements are routinely measured in the marine mammal liver tissues archived in the National Biomonitoring Specimen Bank (NBSB). Results show that hepatic concentrations of vanadium, selenium, silver, cadmium, and mercury are positively correlated with age for beluga whales (Delphinapterus leucas) and of vanadium, selenium, cadmium, and mercury with length for ringed seals (Phoca hispada). Many researchers have reported linear correlations of hepatic selenium, cadmium, and mercury with marine mammal age; however, there is only one other report of a linear correlation of hepatic vanadium with marine mammal age. Vanadium levels are at or below detection limits (< or = 0.01 micrograms/g) in liver tissues of U.S. east coast marine mammals from the NBSB but are present at levels ranging from 0.02 to 1.2 micrograms/g of wet weight in the tissues of Alaskan marine mammals. Although only three bearded seal (Eriganthus barbatus) and three bow-head whale (Balaena mysticetus) liver samples have been analyzed, hepatic vanadium levels also increased with animal size for these species. The presence of relatively high levels of vanadium in the livers of these Alaskan animals may reflect a unique dietary source of vanadium, a unique geochemical source of vanadium, or anthropogenic input to the Alaskan marine environment.

A C30 stationary phase was specifically engineered for carotenoid separations, and carotenoid measurements using this column are compared with those obtained using a somewhat more conventional C18 column. Both methods were used to contribute measurements for the certification of carotenoids in Standard Reference Material 968b, Fat-Soluble Vitamins and Cholesterol in Human Serum. Analytes were extracted from the serum into hexane. Measurements on the C18 column were made using a gradient of acetonitrile, methanol, and ethyl acetate, which is described in detail elsewhere. Measurements on the C30 column were made using a gradient of water, methanol, and methyl tert.-butyl ether.

The National Biomonitoring Specimen Bank (NBSB), a collaborative project of several U.S. government agencies, includes marine mammal tissues collected for the Alaska Marine Mammal Tissue Archival Project (AMMTAP) and the National Marine Mammal Tissue Bank (NMMTB). Tissues were collected from 139 animals representing 13 species of marine mammals from around the U.S. Recently, concentrations for up to 30 elements in liver tissues of nine long-finned pilot whales (Globicephala melas), six harbor porpoises (Phocoena phocoena), and four white-sided dolphins (Lagenorhynchus acutus) from the NMMTB were measured using instrumental neutron activation analysis. Results from analyses of these tissues are presented, compared with results for liver tissues from other marine mammals from the AMMTAP, and compared with published values.

Since 1979 the National Institute of Standards and Technology (NIST) has been involved in environmental specimen banking activities as part of the National Biomonitoring Specimen Bank (NBSB). These activities have focused on the development of procedures for the collection, processing, analysis, and long-term storage of a variety of environmental specimens including: human liver, mussels and oysters, fish tissue (liver and muscle), marine mammal tissues (blubber, liver, and kidney), and marine sediments. The experiences of the NBSB can provide valuable information to assist in the design of new specimen bank efforts. Based on the experiences of the NBSB, the issues that should be addressed in the design and operation of a valid specimen bank program are presented.

A Standard Reference Material (SRM) made from whale blubber has been developed for the validation of methods used for the determination of polychlorinated biphenyl (PCB) congeners and chlorinated pesticides. This material, which is a frozen blubber tissue homogenate, was analyzed using three different analytical techniques. These techniques were based on gas chromatography with electron capture detection on two stationary phases with different selectivity for the separation of PCB congeners and gas chromatography with mass spectrometric detection. The results from these three techniques were in good agreement and were combined to provide certified concentrations for 27 PCB congeners and 15 chlorinated pesticides.

A variety of bonded phase parameters (endcapping, phase chemistry, ligand length, and substrate parameters) were studied for their effect on column retention and selectivity toward carotenoids. Decisions were made on how each of these variables should be optimized based on the separation of carotenoid and polycyclic aromatic hydrocarbon test probes. A column was designed with the following properties: high absolute retention, enhanced shape recognition of structured solutes, and moderate silanol activity. These qualities were achieved by triacontyl (C30) polymeric surface modification of a moderate pore size (approximately 20 nm), moderate surface area (approximately 200 m2/g) silica, without subsequent endcapping. The effectiveness of this "carotenoid phase" was demonstrated for the separation of a mixture of structurally similar carotenoid standards, an extract of a food matrix Standard Reference Material, and a beta-carotene dietary supplement under consideration as an agent for cancer intervention/prevention.

The services offered by the home care division of a medical center should correspond to the needs of both physicians and patients who are to be served. This study addresses the physician segment, the primary referral source for home care. It measures both the absolute and the relative importance of a range of offerings which a home care services division provides in a mid-sized, full service, medical center.

The National Marine Mammal Tissue Bank (NMMTB) has been established as part of a comprehensive effort to obtain reliable information on contaminant levels in marine mammal tissues. A four component program consisting of the NMMTB, stranding networks, monitoring and quality assurance has been developed. The development and current status of the NMMTB and its relationship to the other three components will be described.

Analyses of selected tissues from the Alaska Marine Mammal Tissue Archival Project (AMMTAP) have provided comprehensive information related to levels of 36 trace elements and methyl-mercury in marine mammal tissues. Liver, kidney and muscle tissues from two northern fur seals, four ringed seals and six belukha whales were analyzed. The bulk of the investigated tissues and additional tissues from a total of 65 marine mammals are banked in the AMMTAP. The results are compared to literature values for trace element concentrations in marine mammal tissues and their relevance to environmental studies is discussed.

The cryogenic archival of biological specimens for retrospective analysis is of significant value for present and future research on population genetics, pathology, systematics, toxicology and environmental monitoring. This realization is emphasized by the increasing support of this activity by various government agencies, institutions and international groups. The international Arctic community is no exception. Canada has been conducting such activities in association with environmental monitoring programs for many years. Similar efforts appear to be underway in other polar nations. From the perspective of the United States Arctic, the Alaska Marine Mammal Tissue Archival Project (AMMTAP) was the earliest organized effort to develop an environmental specimen bank specifically designed for longterm archival of biological specimens under cryogenic conditions. The AMMTAP emphasizes use of standardized rigorous sampling and archival protocols, procedures that minimize contamination of samples during collection and maintaining a detailed record of sample history. The development of this specimen bank, recent activities of this project and other cryogenic specimen banks being developed in Alaska are described.

Selected tissues (blubber, liver, kidney and muscle) from marine mammals, which were collected as part of the Alaska Marine Mammal Tissue Archival Project (AMMTAP), were analyzed for polychlorinated biphenyl (PCB) congeners and chlorinated pesticides. Concentrations of these compounds in the different tissues were compared and blubber was selected as the primary tissue for organic contaminant analyses for the AMMTAP based on higher levels (1-2 orders of magnitude) in this tissue compared to liver, kidney and muscle. Concentrations for 15 PCB congeners and 12 chlorinated pesticides are reported for 10 different animals of three species (northern fur seal, ringed seal and belukha whale) from five different sites.

The National Institute of Standards and Technology (NIST) has been involved in biological environmental specimen banking activities since 1979. These activities, which are known collectively as the National Biomonitoring Specimen Bank (NBSB), include the banking of a variety of specimens (human liver, sediment, mussels/oysters, fish tissue and marine mammal tissues) from several different projects supported by different government agencies. The two most recent projects, the Alaska Marine Mammal Tissue Archival Project (AMMTAP) and the National Marine Mammal Tissue Bank (NMMTB), focus on the collection, banking and analysis of marine mammal tissues and they are part of a comprehensive plan to address marine mammal monitoring, specimen banking and quality assurance of analytical measurements associated with contaminant analyses in marine mammals.

Sixty commercially available and five experimental liquid chromatography columns were evaluated for the separation and recovery of seven carotenoid compounds. Methanol- and acetonitrile-based solvents (either straight or modified with ethyl acetate or tetrahydrofuran) were compared to determine which solvent systems and which columns provided better selectivity and recovery. Methanol-based solvents typically provided higher recoveries than did acetonitrile-based solvents. Polymeric C18 phases generally provided better selectivity for the difficult separation of lutein and zeaxanthin than did monomeric C18 phases.

Standard Reference Materials (SRMs) from the National Institute of Standards and Technology (NIST) are often used in methods development and interlaboratory comparison studies since they are homogeneous and readily available to the scientific community. SRM 1649 (urban dust/organics), SRM 1650 (diesel particulate matter), and SRM 1597 (complex mixture of polycyclic aromatic hydrocarbons from coal tar) are three environmental samples which have been used by the scientific community for these purposes. These SRMs were originally developed to assist laboratories in validating analytical procedures for the determination of polycyclic organic compounds in complex mixtures. In addition, these SRMs have been valuable for the comparison of methodologies for bacterial bioassays and the development of bioassay-directed fractionation and bioassay-directed chemical analysis techniques. Most recently these SRMs were chosen for use as test samples in a collaborative study coordinated by the World Health Organization--International Programme on Chemical Safety. This paper provides a summary of much of the work to date (published and unpublished) on the chemical and biological characterization of these three SRMs. Information regarding the availability of other NIST SRMs that might be useful for these types of studies are provided also.

The mounting financial pressures placed on acute care facilities have resulted in many closings and mergers. They have impacted patient services and other traditional areas of hospital concern. The adoption in 1983 of the Prospective Payment System of reimbursement for Medicare clients has forced increased scrutiny by hospitals of length of stay. This study reviewed the pattern of length of stay (LOS) of all 553 Medicare clients referred for assistance with discharge planning through utilization of home care coordination in a midwestern, 150-bed, acute care hospital in 1989. This descriptive, retrospective study anonymously compiled basic demographic data of all such clients in addition to DRG, LOS, and time of initiation of discharge planning activities by the Home Care Coordinator (HCC). One finding of the correlational statistical analyses showed that as the number of days from the clients' admission to HCC contact increased overall LOS increased. Strong implications exist regarding nursing involvement with discharge planning. Identifying needs and making prompt referrals by members of the health care team can provide positive outcomes for clients and the hospital. Impact on the image and reputation of the hospital from early intervention for discharge planning caused by DRG reimbursement clearly pose marketing problems. This paper identifies areas in which appropriate market opportunities may be discovered and addressed as the hospital makes necessary adaptations to DRG reimbursement.

A project to establish an archive of Alaskan marine mammal tissues was conceived in 1987 to be a part of the National Biomonitoring Specimen Bank (NBSB). Protocols and field collection of marine mammals, long-term storage, and analysis are summarized in this paper. Instrumental neutron activation analysis has been used for an initial evaluation of trace element content in samples of northern fur seal (Callorhinus ursinus) from the Pribilof Islands. The findings agree with previously observed trace element levels in northern fur seals. The archived specimens can be used in future studies when comparison of past and present pollution levels are needed.

The validity and intercomparability of data in research related to medical, environmental, and geochemical health problems is of utmost concern and requires specific consideration in the development of an analytical approach. The Environmental Protection Agency/National Bureau of Standards Pilot Environmental Specimen Bank Program provides a vehicle for developing the precise and accurate determination of trace constituents in human livers. This approach, when implemented, gives specific consideration to a valid relationship between the analytical result and the true value in the sample. This is accomplished by minimizing contamination of the sample and/or loss of constituents, and by assuring representative analytical test portions. The analysis of the liver specimens is performed under strict quality control. The applied analytical techniques (atomic absorption spectrometry, isotope dilution mass spectrometry, neutron activation analysis, and voltammetry) have been verified for accuracy through the analysis of Standard Reference Materials. In addition, several elements are determined using two or three of these independent techniques. The first year of the program provided results on 31 elements including Se and Pb in 36 human livers.

The effect of acetaminophen on reducing the frequency and severity of adverse reactions following diphtheria-pertussis-tetanus toxoids-polio vaccine was studied in a randomized clinical trial involving 519 vaccinations in 383 infants 2 to 6 months of age and 70 infants 18 months of age. Significantly fewer local and systemic reactions were reported in acetaminophen-treated infants at 2 to 6 months of age. Acetaminophen also reduced the incidence of fever greater than 38.0 degrees C from 44% to 27%. Only 0.9% of acetaminophen-treated infants had overall behavioral changes rated as severe by parents compared to 13% of the placebo group. Infants vaccinated at 18 months of age had higher rates of systemic and local reactions than younger infants. Acetaminophen did not result in significant reductions in reaction rates after the booster at 18 months. We conclude that acetaminophen administered at the time of primary vaccination with diphtheria-pertussis-tetanus toxoids-polio can significantly reduce the frequency and severity of common adverse reactions.