Biuret test detects compounds containing peptide bonds. Copper ions form purple complexes with peptide bonds in alkaline solution. Color change from blue to violet indicates protein presence
Extraction is the separation of a substance from a matrix. Partition theory describes solute distribution between phases. Various extraction methods include acid-base, supercritical fluid, and microwave
Created by Ehrlich, modified by Ziehl and Neelsen in late 19th century. Initially used for tuberculosis diagnosis, later adapted for other mycobacteria
First edition published in 1905 as Standard Methods of Water Analysis. Joint publication by APHA, AWWA, and WEF since 1925. Methods have undergone significant revisions since 1975
Porosity equals pore volume divided by total volume. Soil particle density is assumed to be 2.66 g/(cm³). Porosity can be expressed as (1 - bulk density) divided by particle density
Pure water has pH of 7, indicating neutrality. pH scale ranges from 0 to 14, with 7 being neutral. pH measures acidity or alkalinity through hydrogen ion changes