Iodometric Semimicroprocedure for Determination of Arsenic in Sodium Cacodylate and Cacodylic Acid

1943 ◽  
Vol 15 (1) ◽  
pp. 76-77
Author(s):  
Victor Levine ◽  
Wallace McNabb
Keyword(s):  
Sodium Cacodylate ◽  
Cacodylic Acid

Determination of Arsenical Herbicide Residues in Plant Tissues

Weed Science ◽  
1971 ◽  
Vol 19 (4) ◽  
pp. 412-416 ◽  
Author(s):  
R. M. Sachs ◽  
J. L. Michael ◽  
F. B. Anastasia ◽  
W. A. Wells
Keyword(s):  
Sulfuric Acid ◽  
Sodium Arsenite ◽  
Colorimetric Method ◽  
Plant Tissues ◽  
Acid Digestion ◽  
Cacodylic Acid ◽  
Solvent Systems ◽  
Critical Requirement ◽  
Paper Chromatographic Separation

Paper chromatographic separation of hydroxydimethylarsine oxide (cacodylic acid), monosodium methanearsonate (MSMA), sodium arsenate, and sodium arsenite was achieved with the aid of four solvent systems. Aqueous extracts of plant tissues removed essentially all the arsenicals applied, but methanolic fractionation was required before the extracts could be analyzed by paper chromatographic procedures. A standard nitric-sulfuric acid digestion procedure was employed for arsenic analyses, but great care was taken to avoid sulfuric-acid-induced charring by first adding relatively large amounts of nitric acid to drive off chlorides present. Depending upon the amount of chloride present, substantial losses of arsenic as arsine chlorides were observed if the samples charred. Five minutes in fuming sulfuric acid to completely break the carbon-arsenic bonds was another critical requirement for the quantitative determination of arsenic from cacodylic acid and MSMA. The silver diethyldithiocarbamate colorimetric method was useful for detecting as little as 0.6 μg or as much as 20 μg of arsenic per sample.

Determination of Organic Arsenicals in Pesticide Formulations by Ion Chromatography

1989 ◽  
Vol 72 (6) ◽  
pp. 994-996
Author(s):  
Connie C Gehrig ◽  
Timothy M Fitzpatrick
Keyword(s):  
Ion Chromatography ◽  
Mobile Phase ◽  
Correlation Coefficients ◽  
Analysis Time ◽  
Chromatography Analysis ◽  
Cacodylic Acid ◽  
Pesticide Formulations ◽  
Relative Standard ◽  
Standard Deviations

Abstract The organic arsenicals, cacodylic acid and methanearsonic acid and their salts, are determined in pesticide formulations by ion chromatography. The samples are diluted in the aqueous mobile phase, injected directly into the chromatograph, and determined by nonsuppressed ion chromatography. Analysis time is less than 5 min for each arsenical. The method was tested for precision, linearity, and recovery. Linearity of the methanearsonic acid gave regression and correlation coefficients of 0.9998 and 0.9999, respectively, and 0.9997 and 0.9998 for cacodylic acid. Quadruplicate analyses of 5 methanearsonic acid samples gave relative standard deviations of 0.833-3.10. Quadruplicate analyses of 4 cacodylic acid samples gave relative standard deviations of 0.648-1.41. Recovery was 100.3 ± 3.6%.

Total arsenic in urine: palladium-persulfate vs nickel as a matrix modifier for graphite furnace atomic absorption spectrophotometry

1991 ◽  
Vol 37 (9) ◽  
pp. 1575-1579 ◽  
Author(s):  
D E Nixon ◽  
G V Mussmann ◽  
S J Eckdahl ◽  
T P Moyer
Keyword(s):  
Graphite Furnace ◽  
Complete Recovery ◽  
Atomic Absorption Spectrophotometry ◽  
Total Arsenic ◽  
Matrix Modifier ◽  
Arsanilic Acid ◽  
Cacodylic Acid ◽  
Target Values ◽  
The Matrix

Abstract We evaluated the effectiveness of nickel and palladium with or without added potassium persulfate as matrix modifiers for the determination of total arsenic in urine. Complete recovery of pure aqueous solutions of As(III), As(V), cacodylic acid (DMA), monomethylarsinic acid (MMA), and o-arsanilic acid was attained by using both nickel and palladium modifiers. Combined arsenobetaine and arsenocholine (so-called fish arsenic), extracted from a certified control material of dogfish muscle (DORM-1), were completely recovered with Pd-S2O8 matrix modification, but not with nickel. Excellent agreement with target values for arsenic in urines from the Centre de Toxicologie du Quebec, supplied by the Interlaboratory Comparison Program, was attained irrespective of the arsenic source when we used Pd-S2O8 as the matrix modifier.

Determination of cacodylic acid (hydroxydimethylarsine oxide) by gas chromatography

1974 ◽  
Vol 46 (1) ◽  
pp. 155-157 ◽  
Author(s):  
C. J. Soderquist ◽  
D. G. Crosby ◽  
J. B. Bowers
Keyword(s):  
Gas Chromatography ◽  
Cacodylic Acid

Galactic orbits of stars

1966 ◽  
Vol 25 ◽  
pp. 93-97
Author(s):  
Richard Woolley
Keyword(s):  
Globular Cluster ◽  
Potential Field ◽  
High Velocity ◽  
Velocity Vector ◽  
Variable Stars ◽  
The Sun ◽  
Proper Motions ◽  
Rr Lyrae ◽  
The Galaxy

It is now possible to determine proper motions of high-velocity objects in such a way as to obtain with some accuracy the velocity vector relevant to the Sun. If a potential field of the Galaxy is assumed, one can compute an actual orbit. A determination of the velocity of the globular clusterωCentauri has recently been completed at Greenwich, and it is found that the orbit is strongly retrograde in the Galaxy. Similar calculations may be made, though with less certainty, in the case of RR Lyrae variable stars.

Distance to SN 1987A and the LMC

1999 ◽  
Vol 190 ◽  
pp. 549-554
Author(s):  
Nino Panagia
Keyword(s):  
Angular Size ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Light Curves ◽  
Distance Modulus ◽  
Absolute Size ◽  
Sn 1987A

Using the new reductions of the IUE light curves by Sonneborn et al. (1997) and an extensive set of HST images of SN 1987A we have repeated and improved Panagia et al. (1991) analysis to obtain a better determination of the distance to the supernova. In this way we have derived an absolute size of the ringRabs= (6.23 ± 0.08) x 1017cm and an angular sizeR″ = 808 ± 17 mas, which give a distance to the supernovad(SN1987A) = 51.4 ± 1.2 kpc and a distance modulusm–M(SN1987A) = 18.55 ± 0.05. Allowing for a displacement of SN 1987A position relative to the LMC center, the distance to the barycenter of the Large Magellanic Cloud is also estimated to bed(LMC) = 52.0±1.3 kpc, which corresponds to a distance modulus ofm–M(LMC) = 18.58±0.05.

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