Determination of Cadmium in Human Serum and Blood Samples after Dispersive Liquid–Liquid Microextraction Using a Task-Specific Ionic Liquid

Microextraction techniques for occupational biological monitoring: Basic principles, current applications and future perspectives

The application of green microextraction techniques (METs) is constantly being developed in different areas including pharmaceutical, forensic, food and environmental analysis. However, they are less used in biological monitoring of workers in occupational settings. Developing valid extraction methods and analytical techniques for the determination of occupational indicators plays a critical role in the management of workers' exposure to chemicals in workplaces. Microextraction techniques have become increasingly important because they are inexpensive, robust and environmentally friendly. This study aimed to provide a comprehensive review and interpret the applications of METs and novel sorbents and liquids in biological monitoring. Future perspectives and occupational indicators that METs have not yet been developed for are also discussed.

Impact of bone marrow mesenchymal stem cells on the submandibular gland structure of adult male albino rats exposed to cadmium chloride toxicity

OBJECTIVE

This study was carried out in submandibular salivary glands of rats to demonstrate the changes induced by cadmium intoxication and the possible prophylactic and therapeutic effects of bone marrow mesenchymal stem cells (BMSCs).

DESIGN

Sixty-five rats were divided into five groups. Rats in Group I were controls while those of Group II received daily dose of 10 mg/kg cadmium for 24 days. Rats in Group III received single prophylactic dose of 1 × 106 BMSCs one week before cadmium administration. Rats of Group IV were concomitantly administered cadmium and BMSCs, while those of Group V received cadmium for 24 days and were then treated with single dose of 1 × 106 BMSCs. Rats of Groups I, II, III, and IV were euthanized at the end of the experiment while those of Group V were euthanized one week later. Salivary gland specimens were processed and stained with H&E and inducible nitric oxide synthase; other specimens were used to demonstrate metallothionein gene expression using RT-PCR, malondialdehyde and catalase enzymes were detected by ELISA.

RESULTS

Groups III and IV had nearly comparable findings to Group I regarding histological pattern with normal gland features. Group III recorded a lower fold of change for metallothionein gene (1.14 ± 0.20), a lower malondialdehyde enzyme (21.67 ± 1.63 nmol/mg), and a higher catalase enzyme (66.33 ± 2.16 mmol/mg). Regarding all variables, significant differences were found between the different groups (P < 0.001).

CONCLUSION

BMSCs have prophylactic and therapeutic effects against cadmium-induced cytotoxicity in rat salivary glands.

Comparison Studies on Several Ligands Used in Determination of Cd(II) in Rice by Flame Atomic Absorption Spectrometry after Ultrasound-Assisted Dispersive Liquid-Liquid Microextraction

Ligands plays an important role in the extraction procedures for the determination of cadmium in rice samples by using flame atomic absorption spectrometry (FAAS). In the present study, comparative evaluation of 10 commercially available ligands for formation of Cd(II)-ligand complex and determination of cadmium in rice samples by ultrasound-assisted dispersive liquid–liquid microextraction (UADLLME) combined with FAAS was developed. Sodium diethyldithiocarbamate (DDTC) provided a high distribution coefficient as well as a good absorbance signal, therefore DDTC was used as a ligand in UADLLME. A low density and less toxic solvent, 1-heptanol, was used as the extraction solvent and ethanol was used as the disperser solvent. In addition, the experimental conditions of UADLLME were optimized in standard solution first and then applied in rice, such as the type and volume of extractant and dispersant, pH, extraction time, and temperature. Under the optimal experimental conditions, the detection limit (3σ) was 0.69 μg/L for Cd(II). The proposed method was applied for the determination of Cd(II) in three different rice samples (polished rice, brown rice, and glutinous rice), the recovery test was carried out, and the results ranged between 96.7 to 113.6%. The proposed method has the advantages of simplicity, low cost, and accurate and was successfully applied to analyze Cd(II) in rice.

Recent applications of microextraction sample preparation techniques in biological samples analysis

Analysis of biological samples is affected by interfering substances with chemical properties similar to those of the target analytes, such as drugs. Biological samples such as whole blood, plasma, serum, urine and saliva must be properly processed for separation, purification, enrichment and chemical modification to meet the requirements of the analytical instruments. This causes the sample preparation stage to be of undeniable importance in the analysis of such samples through methods such as microextraction techniques. The scope of this review will cover a comprehensive summary of available literature data on microextraction techniques playing a key role for analytical purposes, methods of their implementation in common biological samples, and finally, the most recent examples of application of microextraction techniques in preconcentration of analytes from urine, blood and saliva samples. The objectives and merits of each microextration technique are carefully described in detail with respect to the nature of the biological samples. This review presents the most recent and innovative work published on microextraction application in common biological samples, mostly focused on original studies reported from 2017 to date. The main sections of this review comprise an introduction to the microextraction techniques supported by recent application studies involving quantitative and qualitative results and summaries of the most significant, recently published applications of microextracion methods in biological samples. This article considers recent applications of several microextraction techniques in the field of sample preparation for biological samples including urine, blood and saliva, with consideration for extraction techniques, sample preparation and instrumental detection systems.