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Test Items
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Industrial Grade
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Pharmaceutical Grade
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Reagent Grade
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Appearance
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White crystalline powder
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White crystalline powder
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Colorless transparent crystals
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Assay (H3PO3) (%)
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≥98.0
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≥99.0
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≥99.5
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Phosphoric Acid (H3PO4) (%)
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≤0.5
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≤0.2
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≤0.1
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Chloride (as Cl) (%)
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≤0.01
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≤0.005
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≤0.001
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Sulfate (as SO4) (%)
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≤0.02
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≤0.01
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≤0.005
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Iron (Fe) (ppm)
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≤10
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≤5
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≤1
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Heavy Metals (as Pb) (ppm)
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≤10
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≤5
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≤1
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Arsenic (As) (ppm)
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≤5
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≤2
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≤0.5
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Water Insoluble Matter (%)
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≤0.02
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≤0.01
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≤0.005
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Loss on Drying (%)
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≤0.5
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≤0.3
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≤0.1
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