Fire-Assay Emission Spectrographic Method for Platinum, Palladium, Rhodium, and Gold

1970 ◽  
Vol 24 (2) ◽  
pp. 225-228 ◽  
Author(s):  
A. B. Whitehead ◽  
H. H. Heady
Keyword(s):  
Coefficient Of Variation ◽  
Precious Metals ◽  
Matrix Elements ◽  
Graphite Electrodes ◽  
Internal Standards ◽  
Fire Assay ◽  
The Matrix ◽  
Spectrographic Method ◽  
Intensity Ratios

A method has been developed for the determination of microgram levels of Pt, Pd, Rh, and Au. A 10-mg Ag bead containing the precious metals, as extracted by fire assaying, is arced at 8 A dc in graphite electrodes in the presence of 10 mg of either Rh or Pt metal powder. The matrix elements, Ag and Pt, or Rh, serve as internal standards, and intensity ratios Pt/Rh or Rh/Pt, Pd/Rh, and Au/Ag are determined. Precision of the method is about ±5% coefficient of variation for Pt and Rh, ±15% for Pd, and ±19% for Au. Limits of detection are below 1 μg, giving analysis limits (for a 1-assay-ton sample) of about 1–30 ppb for these precious metals.

Spectrographic Determination of Traces of Iron in Copper and Silver by Carrier Distillation

1967 ◽  
Vol 21 (3) ◽  
pp. 151-154 ◽  
Author(s):  
P. Tymchuk ◽  
J. A. H. Desaulniers ◽  
D. S. Russell ◽  
S. S. Berman
Keyword(s):  
High Purity ◽  
Coefficient Of Variation ◽  
Copper Chloride ◽  
Graphite Electrodes ◽  
Spectrographic Determination ◽  
Wide Range ◽  
Silver Matrix ◽  
Spectrographic Method ◽  
Purity Copper

A quantitative spectrographic method has been developed for the determination of traces of iron in high-purity copper and silver. The use of copper chloride as a spectrographic carrier improves the sensitivity and enables the method to be used over a very wide range of concentrations. Samples containing from 0.004 to more than 150 μg of iron (0.07–2500 ppm) can be determined by the identical procedure. A series of 15 replicate copper samples containing 6.4 ppm iron yielded a coefficient of variation of 5.2%. The intensity of the iron spectrum is apparently independent of the copper or silver matrix, which greatly simplifies the preparation of calibration curves. Methods for the preparation of iron-free copper chloride and for purifying graphite electrodes are also outlined.

scholarly journals Total-Burn Spectrographic Determination of Silicon in Plutonium

1967 ◽  
Vol 21 (2) ◽  
pp. 86-88 ◽  
Author(s):  
Roy Ko
Keyword(s):  
Internal Standard ◽  
Germanium Dioxide ◽  
Plutonium Dioxide ◽  
Graphite Electrodes ◽  
Spectrographic Determination ◽  
Spectrographic Method ◽  
Trace Concentrations ◽  
Dc Arc ◽  
Ppm Level

A total-burn spectrographic method has been applied to the determination of trace concentrations of silicon in plutonium. The sample is oxidized to plutonium dioxide, mixed with a germanium dioxide—graphite mixture containing tin internal standard, packed into cupped graphite electrodes, and burned to completion in a high-amperage dc arc. Plutonium spectral interference is avoided by using the less sensitive Si 2506.90-Å line. The lower limit of the determination is 25 ppm of silicon in plutonium. The precision of the method is estimated to be ±8% (coefficient of variation) at the 270-ppm level and ±14% at 40 ppm.

scholarly journals D → π and D → K semileptonic form factors with Nf = 2 + 1 + 1 twisted mass fermions

2018 ◽  
Vol 175 ◽  
pp. 13026
Author(s):  
Vittorio Lubicz ◽  
Lorenzo Riggio ◽  
Giorgio Salerno ◽  
Silvano Simula ◽  
Cecilia Tarantino
Keyword(s):  
Pion Mass ◽  
Form Factors ◽  
Kinematical Region ◽  
Matrix Elements ◽  
Scalar Form ◽  
Mass Collaboration ◽  
Twisted Mass ◽  
The Matrix ◽  
Additional Form

We present a lattice determination of the vector and scalar form factors of the D → π(K)lv semileptonic decays, which are relevant for the extraction of the CKM matrix elements |Vcd| and |Vcs| from experimental data. Our analysis is based on the gauge configurations produced by the European Twisted Mass Collaboration with Nf = 2 + 1 +1 flavors of dynamical quarks. We simulated at three different values of the lattice spacing and with pion masses as small as 210 MeV. The matrix elements of both vector and scalar currents are determined for a plenty of kinematical conditions in which parent and child mesons are either moving or at rest. Lorentz symmetry breaking due to hypercubic effects is clearly observed in the data and included in the decomposition of the current matrix elements in terms of additional form factors. After the extrapolations to the physical pion mass and to the continuum limit the vector and scalar form factors are determined in the whole kinematical region from q2 = 0 up to [see formula in PDF] accessible in the experiments, obtaining a good overall agreement with experiments, except in the region at high values of q2 where some deviations are visible.

scholarly journals KAJI ULANG SNI 13-3487-2005 BARANG – BARANG EMAS DAN SNI 13-3771-1995 BARANG – BARANG EMAS MUDA

2021 ◽  
Vol 23 (1) ◽  
pp. 1
Author(s):  
Joni Setiawan ◽  
Euis Laela ◽  
Istihanah Nurul Eskani ◽  
Nikmah Widiharini ◽  
Farida Farida ◽  
...  
Keyword(s):  
Difference Method ◽  
Precious Metals ◽  
Icp Oes ◽  
Fire Assay ◽  
Purposive Sampling ◽  
Fine Gold ◽  
Gold Platinum

<p>Emas merupakan logam mulia yang dapat dijadikan investasi karena nilainya terus naik dari waktu ke waktu. Barang – barang emas dapat berbentuk batangan, granula, lembaran, perhiasan dan benda seni. Penjaminan mutu kadar emas diatur dalam SNI 13-3487-2005 Barang – barang emas dan SNI 13-3771-1995 Barang – barang emas muda. Pada saat ini emas yang beredar memiliki kadar mulai 3,33% hingga 99,99% (<em>fine gold</em>). Terdapat nilai kadar emas yang belum diatur dalam ke-dua SNI tersebut yaitu barang-barang emas dengan kadar 13,14,15,dan 16 karat. Sehingga perlu dilakukan pengujian untuk melihat kesesuaian kadar emas yang terkandung dalam barang – barang emas yang beredar di pasaran serta peninjauan kembali terhadap metode uji yang ada. Penelitian ini membahas hasil kaji ulang SNI 13-3487-2005 Barang – barang emas dan SNI 13-3771-1995 Barang – barang emas muda sebagai dasar penyusunan SNI barang – barang emas yang baru. Metode penelitian yang dilakukan adalah studi literatur, pengujian sampel barang – barang emas yang beredar yang diambil secara <em>purposive sampling</em>, kemudian dilakukan pengujian <em>fire assay</em> sesuai dengan SNI 13-3487-2005 Barang – barang emas dan ICP-OES sesuai dengan ISO  15093, <em>Jewellery — Determination of precious metals in 999 0 / 00 gold, platinum and palladium jewellery alloys</em> — <em>Difference method using ICP-OES</em>, kajian metode uji, dan penggalian informasi melalui rapat internal, rapat teknis dan rapat konsensus. Berdasarkan pembahasan maka dapat disimpulkan bahwa perlunya penggabungan dua SNI tersebut mencakup kadar 33,3% hingga 99,99%, menetapkan metode uji yang dipergunakan yaitu <em>fire assay</em> dan ICP-OES, dengan acuan normatif yang dipergunakan adalah standar ISO 11596 dan ISO 15039.</p>

scholarly journals A New Lc-Ms/Ms Method for Multiple Residues/Contaminants In Bovine Meat

2020 ◽  
Author(s):  
Zehra Hajrulai-Musliu ◽  
Risto Uzunov ◽  
Stefan Jovanov ◽  
Dean Jankuloski ◽  
Velimir Stojkovski ◽  
...  
Keyword(s):  
Coefficient Of Variation ◽  
Matrix Effects ◽  
Limit Of Detection ◽  
Veterinary Drug ◽  
Detection Capability ◽  
Limit Of Quantification ◽  
Internal Standards ◽  
Anabolic Hormones ◽  
Residual Matrix

Abstract A multi-class and multi-residue/contaminant method for the determination of veterinary drug and pesticide residues and mycotoxins in bovine meat has been developed and validated. The veterinary drug residues/contaminants included antimicrobials, anabolic hormones, lactones, β-agonists, mycotoxins, and pesticides. Isotopic labeled internal standards were included to compensate residual matrix effects. The calibrators used in the method demonstrated linearity with the coefficient of correlation (R2) > 0.98. The decision limit (CCα) values were in the range from 0.067 to 2103.84 μg/kg, while the range for detection capability (CCβ) was from 0.083 to 2482.13 μg/kg. The limit of detection (LOD) and limit of quantification (LOQ) were in the range from 0.059 to 291.36 μg/kg, and 0.081 to 328.13 μg/kg, respectively. The recovery of analytes ranged from 61.28 % to 116.20 %. The intra-day coefficient of variation (CV) was from 0.97 to 25.93 % and the inter-day CV was 2.30-34.04 %. The method has been used for the determination of 49 residues/contaminants in bovine meat.

Calcul d'inerties collectives hydrodynamiques en fission nucléaire

1979 ◽  
Vol 57 (6) ◽  
pp. 793-800 ◽  
Author(s):  
Marie Fontaine ◽  
Pierre Amiot
Keyword(s):  
Velocity Field ◽  
Normal Modes ◽  
Matrix Elements ◽  
Deformed Nuclei ◽  
Inertia Matrix ◽  
The Matrix ◽  
Adiabatic Case

We develop a hydrodynamical method to calculate the inertia matrix elements for highly deformed nuclei. The nuclear velocity field is incompressible but is not limited to the adiabatic case. The formulation is also more general than Werner–Wheeler's. It is shown that off-diagonal terms play an important role in the determination of the normal modes of fission by diagonalization of the matrix.

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