Briscoe M.L.,Brooks Rand Labs in SeattleWA |
Ugrai T.M.,Brooks Rand Labs |
Carter A.T.,Operations at Brooks Rand Labs |
Creswell J.,Research and Development at Brooks Rand Instruments
Spectroscopy (Santa Monica) | Year: 2015
An interlaboratory comparison study for the measurement of arsenic species in rice, kelp, and apple juice was carried out. The purpose of the study was to enable participating laboratories to evaluate their analytical capability to determine inorganic arsenic, arsenite, arsenate, monomethylarsonic acid, and dimethylarsinic acid, assess the intercomparability of the data generated, and look for any correlation trends between the results and the analytical procedures used. Approximately, 66% of laboratories achieved an overall score of 3 (good) or 4 (outstanding), based on the absolute Z-value statistical analysis procedure, indicating that there was generally good agreement between the labs reporting arsenic speciation data for food matrices. However, only 15% of laboratories achieved an overall score of 4, which could be indicative that further method development needs to be carried out to achieve a higher level of consistency across multiple laboratories worldwide using different analytical procedures. © 2015 Advanstar Communications, Inc. All rights reserved.
Creswell J.E.,Brooks Rand Instruments |
Carter A.,Brooks Rand Labs |
Engel V.L.,Brooks Rand Instruments |
Metz J.A.,Brooks Rand Instruments |
Davies C.A.,Brooks Rand Instruments
Water, Air, and Soil Pollution | Year: 2015
We have conducted an interlaboratory comparison study for total mercury and methylmercury analysis in natural (unspiked) water samples annually for the past 4 years. The samples were primarily freshwater, with the exception of one coastal seawater sample in 2014. The study provided participants with an opportunity to assess the quality of their measurements and the intercomparability of their data with their peers. Data on analytical methods used were collected and used to determine whether any methods yield biased results and should be discontinued. The majority of participants received performance scores of 3 or higher, indicating satisfactory performance and results close to the consensus means. However, the coefficients of variation between labs were greater than 20 % in most cases, which may not be sufficiently precise for multilaboratory environmental research, where the processes being studied may vary by 20 % or less. Total mercury analysis methods that do not use gold amalgamation were shown to be underperforming relative to those that do. No significant correlation was observed between sample storage time or temperature and total mercury recovery. Methylmercury analysis methods that do not use distillation performed poorly relative to those that use distillation. © 2015 Springer International Publishing Switzerland.
Taylor V.F.,Dartmouth College |
Carter A.,Brooks Rand Labs |
Davies C.,Brooks Rand Labs |
Jackson B.P.,Dartmouth College
Analytical Methods | Year: 2011
An automated system for methyl Hg analysis by purge and trap gas chromatography (GC) was evaluated, with comparison of several different instrument configurations including chromatography columns (packed column or capillary), detector (atomic fluorescence, AFS, or inductively coupled plasma mass spectrometry, ICP-MS, using quadrupole and sector field ICP-MS instruments). Method detection limits (MDL) of 0.042 pg and 0.030 pg for CH 3Hg + were achieved with the automated Hg analysis system configured with AFS and ICP-MS detection, respectively. Capillary GC with temperature programming was effective in improving resolution and decreasing retention times of heavier Hg species (in this case C 3H 7Hg +) although carryover between samples was increased. With capillary GC, the MDL for CH 3Hg + was 0.25 pg for AFS detection and 0.060 pg for ICP-MS detection. The automated system was demonstrated to have high throughput (72 samples analyzed in 8 h) requiring considerably less analyst time than the manual method for CH 3Hg + analysis described in EPA 1630. © 2011 The Royal Society of Chemistry.
Powell-Hernandez M.,Brooks Rand Labs |
Maizel A.,Brooks Rand Labs |
Thomas R.,Scientific Writing Solutions
Spectroscopy (Santa Monica) | Year: 2012
Urinary metal concentrations may be effective indicators of particulate metal fume exposure and provide a better understanding of specific exposure-response relationships if an analytical method can be developed that is sufficiently sensitive to measure levels at or near background concentrations. Analyzing urine samples by inductively coupled plasma-mass spectrometry (ICP-MS) poses several distinct challenges as the matrix contains components likely to cause false-positives and reduced analytical sensitivity. This study will demonstrate a method that mitigates these problems and produces quantifiable results even at low parts-per-trillion concentrations.
Monnot A.D.,Cardno ChemRisk |
Tvermoes B.E.,Cardno ChemRisk |
Gerads R.,Brooks Rand Labs |
Gurleyuk H.,Brooks Rand Labs |
Paustenbach D.J.,Cardno ChemRisk
Food Chemistry | Year: 2016
Concerns have recently been raised about the presence of arsenic (As) in wine. In this analysis, 101 different California wines were evaluated for organic and inorganic As concentration. The average concentrations of total inorganic As in red, blush and white wines were 6.12 μg/L (range: 0.40-20.5 μg/L), 21.6 μg/L (range: 0.92-41.2 μg/L) and 9.5 μg/L (0.57-30.4 μg/L). The average concentrations of total organic As in red, blush and white wines were 0.64 μg/L (0.10-2.74 μg/L), 0.99 μg/L (0.50-2.28 μg/L), and 0.51 μg/L (0.10-1.78 μg/L). A screening level risk assessment was conducted to assess the potential non-carcinogenic risk resulting from wine consumption. The hazard quotient (HQ) for the inorganic As RfD and the As content of red, blush and white wines was each less than one; indicating that the non-cancer health risk was insignificant. Results indicate that ingestion of California wine does not pose a hazard due to inorganic As content. © 2016 Elsevier Ltd. All rights reserved.
PubMed | Cardno ChemRisk and Brooks Rand Labs
Type: | Journal: Food chemistry | Year: 2016
Concerns have recently been raised about the presence of arsenic (As) in wine. In this analysis, 101 different California wines were evaluated for organic and inorganic As concentration. The average concentrations of total inorganic As in red, blush and white wines were 6.12g/L (range: 0.40-20.5g/L), 21.6g/L (range: 0.92-41.2g/L) and 9.5g/L (0.57-30.4g/L). The average concentrations of total organic As in red, blush and white wines were 0.64g/L (0.10-2.74g/L), 0.99g/L (0.50-2.28g/L), and 0.51g/L (0.10-1.78g/L). A screening level risk assessment was conducted to assess the potential non-carcinogenic risk resulting from wine consumption. The hazard quotient (HQ) for the inorganic As RfD and the As content of red, blush and white wines was each less than one; indicating that the non-cancer health risk was insignificant. Results indicate that ingestion of California wine does not pose a hazard due to inorganic As content.