Use of Dispersive Liquid-Liquid Microextraction and UV-Vis Spectrophotometry for the Determination of Cadmium in Water Samples

Table 1

Resume of the experimental designs' conditions and results for determination of cadmium with two extraction solvents using DLLME and UV-Vis spectrophotometry.

Factor	Low level	High level	Factor significance	Sign of effect
Carbon tetrachloride
Temperature (°C)	25	50	Significant	Positive
Volume of dispersant (mL)	0.5	1.5	Nonsignificant	Negative
Dithizone concentration (mg/L)	52	154	Significant	Positive
Type of dispersant	Ethanol	Methanol	Nonsignificant	Negative
Chloroform
Temperature (°C)	25	40	Significant	Positive
Volume of dispersant (mL)	0.5	1.5	Significant	Positive
Dithizone concentration (mg/L)	34	102	Nonsignificant	Negative
Type of dispersant	Ethanol	Methanol	Nonsignificant	Positive

Screening designs.
2⁴ full factorial designs.
Total number of runs: 32 (with duplicates, in four blocks).