444444444444444444444444444444444444444444444444444444444444444 EMISSION MEASUREMENT TECHNICAL INFORMATION CENTER NESHAP TEST METHOD 444444444444444444444444444444444444444444444444444444444444444 (EMTIC M-108C 1-18-96) Method 108C - Determination of Arsenic Content in Ore Samples from Nonferrous Semlters 1. Applicability and Principle 1.1 Applicability. This method applies to the determination of inorganic arsenic (As) content of process ore and reverberatory matte samples from nonferrous smelters and other sources as specified in the regulations. This method is applicable to samples having an analytical concentration less than 10 ]jg As/ml. 1.2 Principle. Arsenic bound in ore samples is liberated by acid digestion and analyzed by the molybdenum blue photometric procedure. 2. Apparatus 2.1 Sample Preparation and Distillation. 2.1.1 Analytical Balance. To measure to within 0.1 mg. 2.1.2 Erlenmeyer Flask. 300-ml. 2.1.3 Hot Plate. 2.1.4 Distillation Apparatus. No. 6, American Society for Testing and Materials (ASTM) E50, reapproved 1986 (incorporated by reference - seeFIELD( 60.18); detailed in Figure 108C-1. 2.1.5 Graduated Cylinder. 50-ml. 2.1.6 Perchloric Acid Fume Hood. 2.2 Analysis. 2.2.1 Photometer. Capable of measuring at 660 nm. 2.2.2 Volumetric Flasks. 50- and 100-ml. 3. Reagents Unless otherwise specified, use ACS reagent grade (or equivalent chemicals) throughout. 3.1 Sample Preparation. 3.1.1 Water. Deionized distilled to meet ASTM Specification D 1193-74, Type 3 (incorporated by reference - see 61.18). When high concentrations of organic matter are not expected to be present, the analyst may omit the KMn04 test for oxidizable organic matter. 3.1.2 Nitric Acid (HN03), Concentrated. HANDLE WITH CAUTION. 3.1.3 Hydrofluoric Acid (HF), Concentrated. HANDLE WITH CAUTION. 3.1.4 Sulfuric Acid (H2S04), Concentrated. HANDLE WITH CAUTION. 3.1.5 Perchloric Acid (HC104), 70 Percent. HANDLE WITH CAUTION. NOTE: Because of its caustic, hygroscopic, and deflagrating nature, use extreme care in handling HC104. Keep separate from Prepared by Emission Measurement Center EMTIC M108CEMAD, OAQPS, EPAwater and oxidizable materials to prevent vigorous evolution of heat, spontaneous combustion, or explosion. Heat solutions containing HC104 only in hoods specifically designed for HC104. 3.1.6 Hydrochloric Acid (HC1) , Concentrated. HANDLE WITH CAUTION. 3.1.7 Dilute Hydrochloric Acid. Add one part concentration HC1 to nine parts water. 3.1.8 Hydrazine Sulfate [ (NH2)2.H2S04 ] . 3.1.9 Potassium Bromide (KBr). 3.1.10 Bromine Water, Saturated. ------- 3.2 Analysis. 3.2.1 Water. Same as in Section 3.1.1. 3.2.2 Methyl Orange Solution, 1 g/liter. 3.2.3 Ammonium Molybdate Solution, 5 g/liter. Dissolve 0.5 g(NH4)6Mo702 4.4H20 in water in a 100-ml volumetric flask, and dilute to the mark. This solution shall be freshly prepared. 3.2.4 Standard Arsenic Solution, 10 g As/ml. Dissolve 0.1320 g of As203 in 100 ml HC1 in a 1-liter volumetric flask. Add 200 ml of water, cool, dilute to t) ------- |