LaMotte smart spectro 2 Operator's Manual

Contents

LaMotte smart spectro 2 Operator's Manual Manual pdf 15 page image

SMART Spectro 2 Operator’s Manual 04.16 15 PREPARING DILUTE STANDARD SOLUTIONSStandard solutions should be prepared to create a calibration curve. Standard solutionscan be prepared by diluting a known concentrated standard by specified amounts. Achart or computer spreadsheet can be created to determine the proper dilutions. Usevolumetric flasks and volumetric pipets for all dilutions.1. In Column A – Record the maximum concentration of test as determined by the rangeand path length.2. In Column B – Record the percent of the maximum concentration the standardsolution will be.3. In Column C – Calculate the final concentration of the diluted standard solutionsby multiplying the maximum concentration (In Column A) by the % of maximumconcentration divided by 100. (C = A x ).4. In Column D – Record the final volume of the diluted sample (i.e. volume of volumetricflask).5. In Column E – Record the concentration of the original standard.6. In Column F – Calculate the milliliters of original standard required (C x D/E = F).A sample chart appears below:A B C=A x B/100 D E F=C x D/EMaximumconcentrationof test% of MaximumconcentrationFinal concentration ofDiluted StandardVolume ofStandardConcentration ofOriginal StandardmL ofOriginal StandardRequired10.0 ppm 90 9.0 ppm 100 mL 1000 ppm 0.90 mL10.0 ppm 70 7.0 ppm 100 mL 1000 ppm 0.70 mL10.0 ppm 50 5.0 ppm 100 mL 1000 ppm 0.50 mL10.0 ppm 30 3.0 ppm 100 mL 1000 ppm 0.30 mL10.0 ppm 10 1.0 ppm 100 mL 1000 ppm 0.10 mL10.0 ppm 0 0 ppm 100 mL 1000 ppm 0 mL STANDARD ADDITIONSA common method to check the accuracy and precision of a test is by standardadditions. In this method a sample is tested to determine the concentration of the testsubstance. A second sample is then “spiked” by the addition of a known quantity of thetest substance. The second sample is then tested. The determined concentration of thespiked sample should equal the concentration of the first plus the amount added with thespike. The procedure can be repeated with larger and larger “spikes.” If the determinedconcentrations do not equal the concentration of the sample plus that added with the“spike”, then an interference may exist.info@GlobalScientificSupply.comwww. GlobalScientificSupply .com GLOBAL SCIENTIFIC SUPPLYThe Laboratory Supply Company!