A new procedure for determination of nickel in some fake jewelry and cosmetics samples after dispersive liquid–liquid microextraction by FAAS

Abstract

A new, simple and cheap dispersive liquid–liquid microextraction (DLLME) procedure was optimized for the preconcentration of trace amounts of Ni(II) as a prior step to its determination by flame atomic absorption spectrometry (FAAS). It is based on the microextraction of nickel, where appropriate amounts of the extraction solvent (CHCl3), disperser solvent (ethanol) and chelating agent, name 5‐[(Z)‐isoxazol‐3‐yl‐diazenyl]‐2‐methyl‐quinolin‐8‐ol (MMD), were firstly synthesized/characterized and used. Various parameters that affect the extraction procedure such as pH, centrifugation rate and time, the chelating agent (MMD) concentration and sampling volume on the recovery of Ni(II) were investigated. The preconcentration of a 20 ml sample solution was thus enhanced by a factor of 80. The resulting calibration graph was linear in the range of 0.24–10 mg L−1 with a correlation coefficient of 0.9998. The limit of detection (3 s/b) obtained under optimal conditions was 1.00 μg L−1. The relative standard deviation for certified reference material determinations was 1.2%. The accuracy of the method was verified by the determination of Ni(II) in the certified reference material of wastewater (Waste water CWW TMD). The proposed procedure was successfully applied to the determination of Ni(II) in some fake jewelry and cosmetics samples.

Risk assessment of trace metals in sunblock creams using DABCOnium-based ionic liquid–functionalized magnetic nanoparticles

“…A further comparison of the developed method with the existing methods indicated that the RSDs were similar to those of the tandem ionic liquid–based dispersive microextraction method using a syringe air–assisted vesicle system (TIL-DμE-ISAVS) method 55 and higher than those of DLLME, 56 M-SPE 57 and SPE 58 methods. Moreover, the methods using dispersive liquid–liquid microextraction (DLLME) 56,59 for analyte extraction do not report reusability tests; but in the MD-μ-SPE method, the sorbent is reusable (up to eight cycles). The excellent adsorption capacity of Fe 3 O 4 @(SU-DBC) NPs allowed a minimal amount of adsorbent to be used during this study.…”

Sample Preparation of Cosmetic Products for the Determination of Heavy Metals

“…The pH was adjusted to 8 using NH 3 /NH 4 C l . In their second study, the determination of nickel in lipstick, lip gloss, hand creams, and shaving foams is presented [33]. The methodology used was the same as in their first study, but as a chelating agent they used 5-[(Z)-isoxazol-3-yl-diazenyl]-2-methyl-quinolin-8-ol (MMD).…”