EFFECTS OF WATER TEMPERATURE, TECHNICIAN, EXTRACTION TIME, AND DISSOLUTION TIME ON SALT CONCENTRATION USING THE QUANTAB CHLORIDE TITRATOR METHOD

摘要

There are several methods to test the uniformity of a feed mix, such as chemical assay, colored iron filings, and chloride ion test. The Quantab chloride titrator method is a rapid test for chloride concentration. However, the two Quantab procedures commonly used by the food and feed industries to determine the salt concentration are not approved scientific methods. The objective of this study was to determine the effects of water temperature, technician, extraction time, and dissolution time on the concentration of salt measured with the Quantab strip. Experiment 1 treatments were arranged as a completely randomized design to determine the effect of water temperature (20 degrees C, 40 degrees C, and 60 degrees C) on salt concentration. Experiment 2 treatments were arranged in a 3 x 3 factorial of equipment type (adjustable 100 mL dispenser, graduated cylinder, and balance) with three technicians to determine the accuracy of measuring 90 g (90 mL) of distilled water at room temperature. Experiment 3 treatments were arranged in a 2 x 3 factorial of water temperature (20 degrees C to 23 degrees C, i.e., room temperature, and 60 degrees C) and equipment type (adjustable 100 mL dispenser, graduated cylinder, and balance) to determine the accuracy of measuring 90 g (90 mL) of distilled water. Experiment 4 treatments were arranged in a 3 x 3 factorial of water temperature (20 degrees C, 40 degrees C, and 60 degrees C) and extraction time by stirring (15, 30, and 60 s) to determine the salt concentration. Experiment 5 treatments were arranged in a 3 x 3 factorial of water temperature (20 degrees C, 40 degrees C, and 60 degrees C) and dissolution time (0, 6, and 12 min) to determine the salt concentration and the effect of dissolution time on the percent coefficient of variation (% CV). There were three replicates per treatment, and data were analyzed using the GLM and GLIMMIX procedures in SAS. The results of experiment 1 indicated that increasing water temperature increased the concentration of salt extracted from the feed sample (p 0.0001). The results of experiment 2 indicated an interaction between the technician and the type of equipment used to measure the water (p 0.0001). The results of experiment 3 indicated an interaction between the water temperature and the type of equipment used to measure the water (p 0.0001). The results of experiment 4 indicated no interaction between water temperature and extraction time by stirring (p = 0.2295); stirring time did not significantly affect the salt concentration, but increasing water temperature increased the salt concentration (p 0.0001). The results of experiment 5 indicated no interaction between water temperature and dissolution time (p = 0.5679), but water temperature and dissolution time both affected the salt concentration (p = 0.0136 and p 0.0001, respectively). In addition, the % CV results demonstrated that the different dissolution times had no effect on % CV (p = 0.1864). These experiments indicate that a balance should be used for measuring hot distilled water at 60 degrees C, and that 30 s of extraction by stirring, followed by immediately placing the strip into the solution after extraction, should be used for the Quantab chloride titrator method.