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Selenium (Se) is considered to be an essential trace element needed for all living organisms. The importance, deficiency, and toxic effects of Se mainly depend on its quantity and chemical nature. It has been observed that the inorganic versions of Se are more hazardous than the organic versions. This review is mainly focused on the application of different extraction methods used for Se extraction and determination such as microextraction, solid-phase extraction (SPE), and their modified modes in the last 12 years. The use of different dispersive medium (magnetic field, ultrasonic radiation, and vortex agitator) to enhance Se separation is also part of this review. The usage of environmentally friendly solvents such as supramolecular solvents, hydrophobic deep eutectic solvents (DESs), and ionic liquids (ILs) are also the focus of attention in this review. This review is also emphasized the application of advanced microextraction methods, particularly liquid-phase microextraction (LPME). The most recent advances in LPME extraction techniques for Se in various environmental samples, as well as their prospects, are reviewed. Additionally, a summary of cheap, simple, and accurate techniques that have not yet been used to determine small amounts of Se has been provided.

Two extraction procedures, namely dispersive liquid-liquid microextraction (DLLME) and dispersive liquid-liquid microextraction based on solidification of floating organic drop (DLLME-SFOD), have been compared for the spectrophotometric determination of Fe (III). In both procedures, Fe (III) was extracted after complexation with gallic acid in the presence of cetyltrimethylammonium bromide (CTAB). Tetrachloroethylene and 1-undecanol were used as extraction solvents in DLLME and DLLME-SFOD, respectively, while acetone was used as dispersing solvents. The effects of various experimental parameters (solution pH, the concentration of ligand and CTAB, as well as nature and amount of extraction and disperser solvents) on the extraction efficiency were investigated. Under optimum conditions, the calibration graphs were linear in the range of 50.0–650.0 and 8.0–800.0 μg L−1 and the detection limits were 15.0 and 5.0 μg L−1 for DLLME and DLLME-SFOD, respectively. The presence of NaCl, up to 1.0% (w/v) did not impact the extraction procedures. The analyte was good tolerated in the presence of most concomitant ions. The procedures were applied for the determination of Fe (III) in standard reference materials and real samples with good recoveries (95.5–99.0%) for DLLME-SFOD while poor recoveries (68.0–82.5%) were obtained when DLLME was applied. The analytical figures of the procedures were comparable with those listed in the literature and it could be concluded that DLLME-SFOD may be considered one of the best tools used for preconcentration of Fe (III), owing to its simplicity, time-saving and the possibility of using in conventional analytical laboratories. Graphical abstract

For the first time, air-assisted cloud point extraction (AACPE) was presented to preconcentrate metal ions. The procedure was conjugated with inductively coupled plasma-optical emission spectroscopy for determination of samarium. In this procedure, samarium ions were complexed with aluminon and extracted into Triton X-114 in the presence of potassium iodide. The mixture was repeatedly sucked and dispersed with a syringe (three times) to create cloud solution. Experimental factors that affect the extraction competence of the AACPE procedure, such as pH, amount of aluminon and Triton X-114, salt addition, number of suction/injection cycles, and centrifugation rate and time, have been investigated and optimized. A linear calibration curve from 0.2 to 200.0 μg L−1 with enrichment factor and detection limit of 102 and 0.06 μg L−1, respectively, was established under the optimum experimental conditions. The approach was used to determine samarium in wastewater and rock samples, with recoveries ranging from 98% to 99%. Graphical abstract

Contradictory results are existed in the literature regarding the impact of trace elements on the pathogenesis of calcium oxalate (CaOx) stone patients. Therefore, the aim of our study was to investigate the effect of Cu and Zn on biochemical and molecular characteristics of CaOx stones. Plasma and urine concentrations of Cu and Zn in 30 CaOx stones patients and 20 controls were determined by flame atomic absorption spectrometry (FAAS). Urinary levels of citric acid and oxalate were measured by commercial spectrophotometric kits. Blood levels of glutathione reduced (GSH) and catalase (CAT) were determined as markers of antioxidant activity, while blood malondialdehyde (MDA) and urine level of nitric oxide (NO) were used to assess oxidative stress. Gene expression of MAPk pathway (ERK, P38, and JNK) were estimated. The plasma and urine levels of Cu were significantly increased in the patient group compared to those of controls, while the levels of Zn were decreased. Excessive urinary excretion of citric acid and oxalate were found among CaOx stone patients. The GSH and CAT concentration were significantly reduced in CaOx stones patients compared to healthy group. The plasma MDA and urine NO concentration were significantly increased in CaOx stones patients compared to control group. The expressions of the studied genes were significantly increased in CaOx stones patients. These findings suggest that alteration in Cu and Zn might contribute to pathogenesis of CaOx patients through oxidative stress and MAPK pathway genes (ERK, P38 and JNK).

BACKGROUND Toxic metals are associated with cancer progression. Studies have reported the relation between some toxic metals and renal cell carcinoma (RCC). METHODS AND RESULTS Blood levels of Cd and Pb were determined in 94 RCC patients (RCC group) and 91 matched controls as well as blood level of malondialdehyde (MDA) and catalase (CAT) activity as markers of oxidative stress and antioxidant, respectively. Gene expression of MAP kinase pathway (P38 and JNK), hypoxia-inducible factor 1-alpha (HIF1α), vascular endothelial growth factor (VEGF), cytochrome C oxidase subunit 6 (COX6), metallothionein (MT2A), and heat shock protein (HSP90AA1) were evaluated in the obtained tissue specimens. Blood Cd and Pb levels were significantly higher in RCC group comparing to control group with preferential significant increase of Cd in chromophobe RCC (chRCC) sub-type. MDA level was significantly higher and CAT activity was lower in the RCC compared to controls. The difference was evident only in chRCC. The expressions of genes were significantly increased in the cancer tissues than in non-cancerous tissues in RCC sub-types and there was a significant correlation between Cd levels and expression of genes VEGF, MT2A, P38 and JNK in chRCC group. Immunohistochemical staining of clear cell RCC tissues shows a marked expression of VEGF and HIF-1α.While COX6 staining show marked expression in chRCC. CONCLUSIONS There is a positive correlation between Cd toxicity and the development of RCC, especially chRCC sub-type. Cd is strongly incriminated in the pathogenesis of chRCC through the effort on some genes and oxidative stress markers.

To investigate the effect of pomegranate juice (PJ) on the cyclosporine (CsA)-induced nephrotoxicity in rats, 80 rats were divided into four groups. The first group was regarded a negative control group, and the others were as follows: group 2 (CsA group) received CsA in a dose of 25 mg/kg/day orally, group 3 (treated group) received CsA in a dose of 25 mg/kg/day plus 2.5 mL/day of PJ, and group 4 (PJ group) received 2.5 mL of PJ daily. By the end of the 21st day, plasma creatinine, blood urea nitrogen (BUN), creatinine clearance, urinary KIM-1, and NGAL were determined. Histopathological investigation and the determination of malondialdehyde and antioxidant enzymes were analyzed in kidney tissues. The results show that plasma creatinine, BUN, creatinine clearance, and kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin were significantly altered in the CsA group. The supplement of PJ attenuated the alteration in these parameters. The treatment with PJ also prohibits the CsA-induced alteration in the histopathology, lipid peroxidation, and antioxidant enzymes. We can conclude that PJ protects against CsA-induced nephrotoxicity due to its antioxidant effects.

Background: The combination of cloud point extraction (CPE) with inductively coupled plasma-optical emission spectrometry (ICP OES) is limited due to the effect of organic diluent and surfactant on the signal. Methods: A dual-CPE process (d-CPE) was presented for the enrichment of aluminum (Al3+), before determination by ICP OES, to exclude the effect of surfactant and organic solvent on the ICP OES signal. The analyte was firstly extracted into Triton X-114 rich phase as a gallic acid complex. In the second step, Al3+ was back extracted into an aqueous phase of HNO3 that was introduced into ICP OES. The effects of pH, concentrations of gallic acid and Triton X-114, incubation temperature and time, centrifugation conditions and the concomitant ions were evaluated. Results: The method displayed good analytical characteristics at the optimum conditions. An enrichment factor of 49.5 was achieved. The linear calibration graph was obtained from 1.0 to 1000 μg L-1 and the detection limit was 0.31 μg L-1. The relative standard deviation was 2.3% (50 μg L-1 Al3+, n = 10). Quantitative recoveries ranging from 96.0 to 100% were obtained for spiked water and geological samples. This procedure was used efficiently for preconcentration and quantification of Al3+ in various samples by ICP OES. Conclusion: The presented procedure is simple, rapid, accurate, and safe. It can be used for the determination of Al3+ by ICP OES in samples with complicated matrices.

The accurate determination of thorium (Th4+) in the presence of uranyl ions (UO22+) is a challenge facing analytical chemists. In this article, a solidified floating organic drop microextraction procedure (SFODME) combined with inductively coupled plasma-optical emission spectrometry (ICP-OES) is presented for the separation of Th4+ from UO22+. Morin (2′,3,4′,5,7-pentahydroxyflavone) selectively forms a stable complex with Th4+ in an acidic medium (pH 2.5), while UO22+ does not. The formed complex can be separated into an organic drop of 1-undecanol in the presence of ethanol as a dispersive solvent. The major factors influencing the achievement of SFODME, that is, pH, morin concentration, the type and volume of the extracting and dispersive solvents, the sonication conditions, the ionic strength, and the presence of foreign ions, were investigated. Under optimum conditions, the calibration graph was linear in the range of 0.3–400.0 μg L−1. The detection limit and enrichment factor values were 0.12 μg L−1 and 31.1, respectively. The relative standard deviation for 12 replicates was 1.5%. No significant effects from potentially interfering species, including f-block elements, were observed. The procedure was effectively applied for the determination of Th4+ in phosphate rock and ceramic tile samples.

The status of heavy metals in children with lower urinary tract pathology that may harm the upper tract, e.g., neuropathic bladder and posterior urethral valve and its relationship with oxidative stress has not been adequately investigated. Therefore, the object of the current work was to evaluate the concentrations of copper, zinc, cadmium and lead and their relations with levels of catalase (CAT), malondialdehyde (MDA) and glutathione (GSH) in boys with neuropathic bladder and posterior urethral valve.Thirty-six children with neuropathic bladder, 35 children with posterior urethral valve and 33 health controls were included in the study. In addition to routine laboratory tests, blood samples were collected from patients and controls to assess levels of Cu, Zn, Cd and Pb in addition to plasma concentrations of CAT, MDA and GSH.Significantly elevated levels of Cu, Pb, CAT, MDA and GSH and significantly lower concentration of blood Zn were found in the studied groups compared to the controls. In the posterior urethral valve group, blood level of Cu was positively correlated with GSH while a significantly negative relation was observed between blood Zn and CAT activity among the neuropathic bladder patients.Neuropathic bladder and posterior urethral valve may lead to abnormalities in the blood levels of heavy metals (i.e. Cu, Pb and Zn) and markers of oxidative stress (CAT, MDA and GSH). Therefore, the levels of theses metal ions should be monitored during the treatment course of neuropathic bladder and posterior urethral valve patients to prevent or minimize long-term oxidative injury.

In this study, nano-sized cellulose modified with lactic acid (MW-Ce-LA) was prepared with the assistant of microwave then used for the adsorption of Cu2+ from real samples. This modified cellulose was characterized by means of FTIR, TEM, XRD, and elemental analysis. ICP-OES was used for determination of Cu2+. The effect of pH, adsorption times, temperature, sorbent dose, and initial adsorbate concentration were studied to detect the ideal adsorption condition. Langmuir model proved to be the best to fit the adsorption isotherm experiments with maximum adsorption capacity of 90.3 mg g−1 Cu2+. Calculated thermodynamic parameters (ΔG° and ΔH°) for adsorption of Cu2+ on MW-Ce-LA suggested exothermic and nonspontaneous character of the adsorption process. The reusability tests indicated regeneration of the prepared adsorbent simply using 1 mol L−1 of HCl. The examined method was used effectively to preconcentrate Cu2+ from water, blood, and food samples.

In this work, mesoporous strontium titanate nanoparticles (SrTiO3 NPs) were synthesized through a single-step combustion process and were characterized by FT-IR, XRD, SEM-EDX, and TEM. The effects of main parameters that may influence the extraction process (i.e., pH, sorbent amount, time of extraction, eluting agent, and the presence concomitant ions) were investigated. The optimum extraction was achieved at pH 6, 50 mg of sorbent, 20-min shaking time, and 4.0 mL of 0.1 mol L−1 thiourea as desorption agent. Under these conditions, the maximum adsorption capacity was 155.6 mg g−1 with a preconcentration factor of 250 (for a 1000 mL sample solution). The calibration graph was linear up to 1000 μg L−1 and the limit of detection was 1.75 μg L−1. The precision (as relative standard deviation) was 2.53% (n = 10). The procedure was employed for the preconcentration of Pb2+ from blood and urine samples of bladder cancer patients before its determination by FAAS.

Toxic metals are associated with cancer progression. Studies have reported the relation between some toxic metals and renal cell carcinoma (RCC).Blood levels of Cd and Pb were determined in 94 RCC patients (RCC group) and 91 matched controls as well as blood level of malondialdehyde (MDA) and catalase (CAT) activity as markers of oxidative stress and antioxidant, respectively. Gene expression of MAP kinase pathway (P38 and JNK), hypoxia-inducible factor 1-alpha (HIF1α), vascular endothelial growth factor (VEGF), cytochrome C oxidase subunit 6 (COX6), metallothionein (MT2A), and heat shock protein (HSP90AA1) were evaluated in the obtained tissue specimens. Blood Cd and Pb levels were significantly higher in RCC group comparing to control group with preferential significant increase of Cd in chromophobe RCC (chRCC) sub-type. MDA level was significantly higher and CAT activity was lower in the RCC compared to controls. The difference was evident only in chRCC. The expressions of genes were significantly increased in the cancer tissues than in non-cancerous tissues in RCC sub-types and there was a significant correlation between Cd levels and expression of genes VEGF, MT2A, P38 and JNK in chRCC group. Immunohistochemical staining of clear cell RCC tissues shows a marked expression of VEGF and HIF-1α.While COX6 staining show marked expression in chRCC.There is a positive correlation between Cd toxicity and the development of RCC, especially chRCC sub-type. Cd is strongly incriminated in the pathogenesis of chRCC through the effort on some genes and oxidative stress markers.

A cloud point extraction (CPE) process was described for the separation and spectrophotometric analysis of Fe(III) in different water samples and blood as chelating agent. The complexation reaction between Fe(III) and Zincon was elaborated at pH 5.0 using acetate buffer and the complex was quantitatively recovered in a mixed micelle system composed of cethyltri methyl ammonium bromide (CTAB) and Triton X-114. This reaction was carried out at room temperature in the presence of 0.05 mol L-1 Na2SO4 as salting-out electrolyte. The linearity was up to 1000 µg L-1. The preconcentration factor was 50. The precision (as relative standard deviation) and the limit of detection were 2.5% and 3.1 µg L-1, respectively. The proposed procedure was used for the spectrophotometric detection of Fe(III) in water and blood samples and the data were statistically comparable to those achieved using ICP-OES technique.

An accurate and simple preconcentration procedure was presented for cloud point extraction of Co2+, Ni2+ and Cu2+ from water, blood and urine samples. The procedure based on complexation of the metal ions with (E)-2-(2,4-dihydroxybenzylidene)-N-phenylhydrazine-1-carbothioamide (DHBPHC) and subsequent extraction into a surfactant-rich phase of Triton X-114. The optimized procedure (50 mL solution; pH 6; 1 × 10–4 mol L-1 of DHBPHC; 0.08% (v/v) Triton X-114) exhibits linear range up to 500 µg L-1 and limit of detection of 0.34, 0.94 and 0.83 µg L-1 for Co2+, Ni2+ and Cu2+, respectively. Most potentially interferants did not impact the extraction process. The procedure was applied for preconcentration and determination of Co2+, Ni2+ and Cu2+ in water, blood and urine by flame atomic absorption spectrometry.

The electrochemical behavior of rivaroxaban (RIV), a direct Factor Xa inhibitor, was investigated using a glassy carbon electrode (GCE) based on molecularly imprinted polymer (MIP). The MIP was developed by co-polymerization of different monomers (acrylamide and methacrylic acid) with the cross-linker (ethylene glycol dimethacrylate (EGDMA)) in the presence of initiator (potassium persulphate) and RIV as a template. Fourier transform infrared spectroscopy (FT-IR), atomic force microscopy (AFM), energy dispersive X-ray (EDX), and scanning electron microscope (SEM) were used for the characterization of the fabricated polymers. To prepare the potentiometric sensor, the MIP was incorporated in polyvinyl chloride (PVC) in the presence of a plasticizer and coated on the GCE as one layer. While the voltammetric sensor was prepared by drop coating technique, in which the graphene oxide and MIP were deposited on the bare GCE, respectively. Linear response over RIV concentrations in the range of 1.2 × 10

Studies conducted on the chemical composition of Zamzam water are conflicting especially for arsenic. Therefore, the aim of our study is to study the composition of tap and bottled Zamzam water and to compare its quality according to international guidelines of drinking water. Six Zamzam tap water samples as well as one bottled sample were analyzed according to standard methods (APHA) for their chemical constituents (pH, TDS, Na, K, Mg, Ca, Fe, Cu, Zn, Cd, Pb, Mn, Al, As, Cl−, SO4−2, HCO3- and PO4−3). The results were compared to guidelines of WHO and EPA for quality of drinking water. All analyzed parameters were below the maximum allowable limits (MAL) of WHO and EPA (p˃0.05), with the exception of TDS. The average values of TDS (814 mg L−1 in tap zamzam water samples and 812 mg L−1 in bottled sample) were below the MAL of WHO (1000 mg L−1) but exceeded the limit that defined by EPA as a non-enforceable guidelines (500 mg L−1) (p˂0.05). Compared to the collected tap zamzam water samples, bottled sample had significantly lower levels of Na, PO4−3 (p˂0.05) and Cu (p˂0.01). The study concluded that Zamzam water has acceptable chemical composition including arsenic, except for TDS that exceeds the high non-enforceable accepted limit according to EPA., Zamzam water; chemical composition; international guidelines; health effects.

A micelle-mediated procedure was presented for enrichment of Cu2+ using 4-(2-chloroacetamido)-salicylic acid and Triton X-114 as complexing and extracting agents, respectively. The experimental parameters that affect the extraction were investigated and optimized. Good analytical features were achieved including limit of detection (0.25 µg L-1), limit of quantification (0.83 µg L-1), linearity (1.0-500 µg L-1) and reproducibility (2.2%). For 50.0 mL sample, the enrichment factor was 49.5. Most concomitant ions not interfere with Cu2+ determination. The procedure was employed for preconcentration and determination of Cu2+ in different samples (water, blood and urine) by flame atomic absorption spectrometry with satisfying results.

Objectives Pomegranate juice (PJ) is rich in important compounds with anti-cancer activities. This study aims to investigate the preventive effect of pomegranate juice (PJ) against bladder cancer (BC). Methods Eighty male Sprague Dawley rats were randomly classified into 4 equal groups: (1) Normal controls; (2) PJ group: supplied by PJ for 12 weeks; (3) Cancer-induced group: intake 0.05% v/v N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN) for 8 weeks; (4) Cancer-prevented group: BBN + PJ. After 12 weeks, all rats were sacrificed and their urinary bladder tissues were subjected to histopathological and immunohistochemical (p53) examinations, expression of interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), hypoxia-inducible factor 1 (HIF-1) and the tumor protein p53 (TP53) and analysis of oxidative stress markers. Results The development of BC was: 0/20 (0%) in normal, PJ and cancer-prevented groups and 20/20 (100%) in cancer-induced group. Significant neoplastic lesions were observed in cancer-induced group. Mild preneoplastic alterations were noticed in 25% (5/20) of cancer-prevented group. p53 immunostaining were significantly elevated in the cancer-induced group, which was decreased in the cancer-prevented group. The relative expressions of IL-6, TNF-α, HIF-1 and TP53 were significantly lower in the cancer-prevented group compared to the cancer-treated group. Correction in the oxidative stress markers were also observed in the cancer-prevented group. Conclusion PJ possesses a promising inhibitory effect on BC development, probably due to its anti-oxidant and anti-inflammatory properties., Pomegranate juice; Chemoprevention; Bladder cancer; Genetics; Polyphenol; Oxidative stress; Flavonoid; Antioxidant; Molecular biology; Cancer research; Toxicology

Herein, we report the organized investigation on adsorption of Cd(II) and Hg(II) by thioglycolic acid modified mesoporous silica nanoparticles prepared by the sol-gel procedure. The modification process is enhanced by microwave irradiation. The morphological behavior of the prepared sorbent (MCM-41-TgA) was identified by SEM and TEM imaging as well as BET surface area analysis. The proposed chemical properties were confirmed by elemental analysis, FT-IR, XRD, and zeta potential. EDX and FT-IR spectra were used to confirm the adsorption process. Both ions could be quantitatively recovered from aqueous samples at pH 6 after shaking for 30 min at room temperature. The solid phase has relatively high adsorption capacity 91.3 and 42.8 mg g−1 for Cd(II) and Hg(II), respectively. Langmuir isotherm model fitted well with the experimental data confirming the formation of a mono layer with homogeneous adsorption sites. The thermodynamic studies concluded spontaneity and exothermic behavior of the adsorption process. MCM-41-TgA could be regenerated using 0.5 mol L-11 thiourea or EDTA for at least 10 adsorption/desorption cycles, and it was applied to preconcentrate Cd(II) and Hg(II) from real samples before their determination using ICP-OES.

2-(3-Ethylthioureido)benzoic acid was prepared and characterized by electronic spectrum, elemental analysis, Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance spectrum and mass spectrum. The produced ligand was applied for the preconcentrative of Fe3+, Co2+, Cu2+ and Zn2+ in aqueous samples by cloud point extraction methodology. Triton X-114 was used as extractant. Experimental parameters that may affect the extraction process were examined and optimized; such as pH, ligand and triton concentrations, type of diluting solvent, extraction temperature and ionic strength. The calibration curves were linear upto 500 μg L−1 for Fe3+, Cu2+ and Zn2+ and upto 200 μg L−1 for Co2+. The achieved detection limits were 1.5, 0.23, 0.71 and 0.35 μg L−1 for Fe3+, Co2+, Cu2+ and Zn2+ respectively. The accuracy was established by analysis of certified reference materials (Seronorm whole blood L2 and ZCS ZC85006 Tomato). The proposed procedure was used for preconcentration of these metal ions in water, biological and food samples prior to their determination by flame atomic absorption spectrometry.

Microwave assisted preparation of cellulose modified with gallic acid (MA-Cell-GA) was developed for high efficient adsorption of Al3+. The as-prepared modified cellulose has been characterized by elemental analysis, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and zeta potential measurements. Energy dispersive X-ray (EDX) spectrum was utilized to proof the adsorption of Al3+. The effect of various experimental factors, as pH, amount of adsorbent, shaking time, initial metal ion concentration, temperature, concomitant ions and desorption conditions on the extraction efficiency was investigated and optimized in batch mode experiments. The adsorption capacity and the surface area of MA-Cell-GA were 59.6mgg-1 and 160m2g-1, respectively which were significantly higher than those of the sorbent obtained via traditional reflux procedure. The thermodynamic factors (ΔH° and ΔG°) values for adsorption of Al3+ on MW-Cell-GA confirmed the non-spontaneousity and exothermic character of the adsorption process. It was indicated that the prepared adsorbent can be regenerated easily using EDTA. The procedure was successfully applied for the preconcentration of Al3+ in water, rocks, blood and soil samples prior to the determination using inductively coupled plasma optical emission spectrometry (ICP-OES).

A micro-cloud point extraction method was discussed for preconcentration and spectrophotometric quantification of U(VI). The method depends on complex formation between U(VI) and 2-(4-sulphophenyloazo)-1,8-dihydroxy-3,6-naphtalenedisulphonic acid (SPADNS) at pH 7.0 and subsequent extraction of the complex in a mixed surfactant medium (cethyltrimethyl ammonium bromide and Triton X-114). The separation was carried out in the presence of 1% Na2SO4 at room temperature. The calibration curve was linear up to 3000 µg L−1. The enrichment factor, detection limit and precision were 16.0, 1.05 µg L−1, and 2.3%, respectively. The method was employed for the determination of U(VI) in real samples with different matrices.

To evaluate Cu and Zn levels in bladder cancer (BC) patients and their relationship with expression of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor 1 (HIF-1). Plasma levels of Cu and Zn were determined in 66 transitional bladder cell carcinoma patients (BC group) and 60 matched controls. The concentration of Cu and Zn as well as the expressions of both VEGF and HIF-1 were also estimated in cancerous and non-cancerous bladder tissues in the BC group. The results showed that plasma Cu and Cu/Zn ratio were significantly higher in BC group when compared with the control group. In contrast, the plasma Zn in BC group was significantly lower than in the controls. Comparing levels of Cu and Zn in cancerous and non-cancerous bladder tissues among the BC group indicated a significantly higher Cu levels in the cancerous tissues, while Zn levels was significantly lower. There were higher expressions of both VEGF and HIF-1 in the cancerous samples. Moreover, the Cu concentration in cancerous tissues was significantly correlated with expressions of VEGF and HIF-1. Logistic regression analysis revealed that the increase in plasma Cu/Zn ratio and plasma Cu and the decrease in plasma Zn may be risk factors for development of bladder cancer. We concluded that alteration of plasma and bladder tissue levels of both Cu and Zn is correlated with pathogenesis of bladder cancer. The increase in Cu level in cancerous tissues of BC group has an important role in angiogenesis in bladder cancer cells.

Deficiency of essential trace elements (such as Cu or Zn) and accumulation of potentially toxic trace elements (as Cd or Pb) are both known to have adverse effects in hemodialysis (HD) patients. Up to our knowledge, no studies about the permeability of low and high flux polysulfone membranes on metal ions during hemodialysis are available. Therefore, the aim of the present study was to address this issue. Forty one hemodialysis patients (19 were using high flux polysulfone membrane while the remaining were using low flux one) participated in the study. Blood levels of Cu, Zn, Cd and Pb were determined by graphite furnace atomic absorption spectrometry among HD patients, before and after dialysis session, as well as among matched 40 healthy persons. Blood concentrations of Cu and Zn in the whole hemodialysis group was significantly lower than those of the healthy control group, on the other hand the toxic metals (Cd and Pb) levels were observed to be significantly higher among HD patients compared to the normal persons. Among the hemodialysis group, there were no significant differences between the low and high flux dialyzer groups in terms of pre-dialysis blood levels of Cu, Zn, Cd and Pb. In addition, significantly decreased levels of all metal ions were observed after dialysis sessions using either low or high flux membranes. An exception was Pb which did not show any difference between pre-dialysis and post-dialysis values in the low flux groupIn conclusion Zn and Cu deficiencies should be considered in the treatment of these patients. High flux membranes are more efficient than low flux ones in removing excess Cd and Pb. Therefore, when high flux membranes are used, chelation therapy might not be required for Cd and Pb overload.

An eco-friendly, selective, accurate and rapid procedure was developed for determination of Th4+ in the presence of U6+, Sm3+, La3+, Ce4+, Ho3+ and Er3+. Morin selectively forms a complex with Th4+ at pH range 2.0–4.0 that quantitatively extracted into the surfactant-rich phase in the presence of 0.1% (v/v) Triton X-114 and 0.1% (w/v) KI at room temperature. The developed procedure was optimized and used for determination of Th4+ in complex specimens (waste water and phosphate rocks) by inductively coupled plasma - optical emission spectrometry. The procedure possesses wider analytical range (0.3–500.0 µg L−1) and lower detection limit (0.11 µg L−1) compared to other published CPE procedures for Th4+. For a 50.0 mL sample, the enrichment factor was 49.5. The interference effect of most concomitant ions was negligible. The accuracy of the method was estimated by good recoveries (95.0–100.0%) of Th4+ from spiked samples.

A sensitive and selective method for speciation and determination of iron was developed using cloud point extraction combined with spectrophotometry. The method depends on formation of complex between Fe3+ and a newly synthesized reagent, 4-(2-(2,4-dioxopentan-3-ylidene)hydrazinyl)-2-hydroxybenzoic acid (DOPHHBA), and its extraction into Triton X-114 rich phase prior to spectrophotometric determination at 438 nm. Total Fe was determined as Fe3+ by the same methodology after oxidation of Fe2+. The method exhibited dynamic linear range from 4.0 to 500 µg L-1 with limit of detection and enrichment factor of 1.2 µg L-1 and 95.2, respectively. The accuracy of the method was tested by analysis of certified reference materials and spiked samples. The method was applied for speciation of Fe in natural water samples and determination of Fe in food samples with satisfying results. The analytical results are statistically comparable with those obtained by a standard ICP-OES method.

This article covers the applications of cloud point extraction (CPE) methodology for separation and preconcentration of different substances including metal ions, nano-particles and organic molecules. The CPE as any extraction procedure separates the analyte from whole sample into small volume to increase the sensitivity of analysis and to eliminate effect of interference from sample background. The major features of CPE technique over the other separation methods are effectiveness, rapidness, simplicity and safety. It minimizes or ignores the utilization of toxic organic solvents and therefore the procedure is termed as “eco-friendly tool”. In the present review, the application of CPE in the determination of wide range of analytes was discussed with special concern to recent developed procedures. The main advantages and limitations of the technique were also provided.

A simple, sensitive and rapid cloud point extraction (CPE) methodology has been developed for the selective separation and preconcentration of gallium, indium and thallium, after complexation with gallic acid in the presence of Triton X-114 as a non-ionic surfactant. The quantitative extraction of gallium, indium and thallium was performed at pH 2.5, with 0.04 mmol L−1 gallic acid, and 0.05% (w/v) Triton X-114 at 40 °C. The dilution of the surfactant-rich phase with acidified methanol was performed after phase separation, and the metal ions were determined using flame atomic absorption spectrometry. Under the optimized experimental conditions, the calibration curve is linear over the concentration range of 6–150 ng mL−1 for gallium, 2–150 ng mL−1 for indium, and 2–100 ng mL−1 for thallium. The limits of detection, based on three times the standard deviation of a blank signal by seven replicate measurements were 3.50, 1.25 and 0.92 ng mL−1. The relative standard deviations of this method were 1.55, 1.40 and 1.82% for gallium, indium and thallium, respectively (C = 50 ng mL−1, n = 7). The results showed that the developed method was not susceptible to interference effects, providing good recoveries. The developed method was successfully applied to gallium, indium and thallium determination in sediments and mobile phone liquid crystal display samples with satisfactory results.

Titanium oxide nanotubes (TiOxNTs) were prepared using a hydrothermal method followed by ion exchange and phase transformation. The obtained TiOxNTs were decorated with CuFe2O4 quantum dots by assisted microwave procedures. The prepared nanomaterials were characterized by XRD, TEM, and IR spectroscopy. The decorated nanotubes (DTiOxNTs) were used as adsorbents for the removal of U(VI) from aqueous solutions prior to its determination by inductively coupled plasma-optical emission spectrometry. Experimental parameters including pH, contact time and amount of adsorbent were investigated by batch mode. Optimum sorption of U(VI) ions obtained at pH 6–8. The maximum adsorption capacity of DTiOxNTs towards U(VI) was found to be 366 mg g−1 which is better than that obtained by using TiOxNTs (277 mg g−1). The equilibrium adsorption isotherm of U(VI) was fitted with the Langmuir adsorption model. Moreover, a mini-column packed with DTiOxNTs was used for column-mode extraction and preconcentration of U(VI). The effects of layer thickness, sample volume, sample flow rate and eluent conditions were studied. Under the optimized column procedures, the preconcentration factor for U(VI) was 200. The 3σ detection limit and 10σ quantification limit were found to be 0.12 and 0.40 ng mL−1, respectively. The calibration curve was linear up to 1500 ng mL−1. The proposed method showed good performance in analyzing water samples of different sources and soil sample digests collected from agriculture land near an industrial area.

A total of 1291 drinking water samples were examined for nitrite and nitrate during 6 months from December, 2015 to May, 2016 at 17 cities of Dakahlia governorate (Nile Delta, north of Egypt), and the results were utilized for assessment of health risk of the exposure from drinking water by calculating average daily intake (ADI), hazard quotient (HQ), and the hazard index (HI). The nitrite and nitrate in drinking water had a concentration range of 0.030–0.113 and 2.41–8.70 mg L−1, with mean values of 0.059 ± 0.014 and 5.25 ± 1.61 mg L−1, respectively. Nitrite and nitrate levels in rural areas and ground water samples were significantly higher than that in the urban ones. None of the analyzed samples exceeded WHO guideline values that set out to prevent methemoglobinemia. The values of HQ and HI for all age groups do not exceed unity indicating a low risk of methaemoglobinaemia for the population in this area. Results of the present study indicate that there is no health risk of residents from nitrite and nitrate through drinking water in the studied area. However, the other sources of exposure to nitrite and nitrate should be investigated in further studies.

A simple and rapid cloud point extraction methodology has been developed for the separation and determination of palladium, after complexation with benzil mono-(2-pyridyl) hydrazone in acidic medium, using Triton X-114 as nonionic surfactant. Under the optimum experimental conditions, the calibration curve was linear in the range of 0.05–25 µg L−1. The enrichment factor was 104 for a 50 mL sample volume. The limits of detection, based on three times the standard deviation of the blank signal by seven replicate measurements was 0.12 µg L−1. The relative standard deviation (RSD) for seven replicate determination at 5 µg L−1 of palladium was 1.85 %. Under the presence of foreign ions and EDTA as a strong complexing agent, no significant interference was observed. The accuracy of the results was verified by analyzing spiked water samples. The proposed method has been applied for the separation and determination of palladium from synthetic highly active radioactive waste with satisfactory results.

A selective and effective cloud point extraction procedure was presented for separation of Gd3+ from other f-block elements (i.e. La3+, Ce3+, Nd3+, Sm3+, Ho3+, Er3+, Th4+ and U6+). The procedure depends on the formation of stable hydrophobic complex between Gd3+ and quercetin at pH 3.0. The formed complex was extracted at room temperature into surfactant rich phase “Triton X-114” in the presence of 0.1 mol L−1 KI. The procedure was also used for enrichment of Gd3+ prior its determination by ICP-OES. At optimum conditions, the proposed procedure displays good analytical linearity (0.1–200 μg L−1) with limit of detection and limit of quantification of 0.03 and 0.11 μg L−1, respectively. The enrichment factor was 49.2 for 50 mL sample. The analyte was quantitatively tolerated in the presence of most concomitant ions. The procedure was then employed for the analysis of Gd3+ in ore, urine and synthetic samples.

A cloud point extraction procedure is proposed for preconcentration of trace amounts of palladium (II), silver (I) and gold (III) in aqueous medium. The metal ions in the initial aqueous solution were extracted using the non-ionic surfactant, Triton X-114 after complex formation with 4-( p -chlorophenyl)-1-(pyridin-2-yl)thiosemicarbazide at pH 6.0 in the presence of 0.3 mol L −1 sodium sulfate as a salting-out agent at 25 °C. Dilution of the surfactant-rich phase with acidified methanol was performed after phase separation, and the metal ions were determined by electrothermal atomic absorption spectrometry. The main factors affecting extraction procedure, such as pH, concentration of the ligand, and amount of Triton X-114 were studied in detail. Under the optimum experimental conditions, the calibration graphs were linear upto 125, 50 and 100 μg L −1 and the enrichment factors were 52, 46 and 56 for palladium, silver and gold, respectively. The limits of detection, based on three times of standard deviation of blank signal by 10 replicate measurements divided by the slope of calibration curves were 0.12, 0.08 and 0.30 μg L −1 for palladium, silver and gold, respectively. The accuracy of the results was verified by analyzing spiked water samples. The proposed method has been applied for the determination of the metal ions in soil and rock samples with satisfactory results.

A highly sensitive and selective technique for the speciation of platinum by cloud point extraction prior to determination by graphite furnace atomic absorption spectrometry (GFAAS) was described. The separation of Pt(II) from Pt(IV) was performed in the presence of 4-(p-chlorophenyl)-1-(pyridin-2-yl)thiosemicarbazide (HCPTS) as chelating agent and Triton X-114 as a non-ionic surfactant. The extraction of Pt(II)–HCPTS complex needs temperature higher than the cloud point temperature of Triton X-114 and pH = 7, while Pt(IV) remains in the aqueous phase. The Pt(II) in the surfactant phase was analyzed by GFAAS, and the concentration of Pt(IV) was calculated by subtraction of Pt(II) from total platinum which was directly determined by GFAAS. The effect of pH, concentration of chelating agent, surfactant, and equilibration temperature were investigated. An enrichment factor of 42 was obtained for the preconcentration of Pt(II) with 50 mL solution. Under the optimum experimental conditions, the calibration curve was linear up to 30 μg L−1 with detection limit of 0.08 μg L−1 and the relative standard deviation was 1.8%. No considerable interference was observed due to the presence of coexisting anions and cations. The accuracy of the results was verified by analyzing different spiked samples (tap water, blood plasma and urine). The proposed method was applied to the speciation analysis of Pt in blood plasma and urine with satisfactory results.

A cloud point extraction (CPE) system for the graphite furnace atomic absorption spectrometric (GFAAS) determination of Pt(IV) has been developed. The procedure is based on the complexation of Pt(IV) with 4-(p-chlorophenyl)-1-(pyridin-2-yl)thiosemicarbazide (HCPTS) in the presence of Triton X-114 as a non-ionic surfactant. The optimum conditions for the procedure were investigated with respect to several experimental parameters such as pH of the solution, Triton X-114 and HCPTS concentrations, incubation time and temperature, and centrifugation rate and time. Under the optimum experimental conditions, the calibration curve was linear up to 50 ng mL−1 with a detection limit of 0.25 ng mL−1 and the enrichment factor was 47. No considerable interference was observed due to the presence of coexisting anions and cations. The accuracy of the results was verified by analyzing the spiked water from different sources (tap, river, brackish, sea and industrial waste water). The proposed method has been applied for the determination of Pt(IV) in some real samples such as food and geological samples with satisfactory results.

Amino silica gel functionalized with 2-hydroxy-5 -(2-hydroxybenzylideneamino)benzoic acid was synthesized, characterized and used as adsorbent for the removal of Ga3+, In3+ and Tl3+ from aqueous solution prior to their determination by flame atomic absorption spectrometry. Experimental parameters that affect the separation process were investigated in both batch and column modes. The maximum adsorption capacities of the sorbent are 61.7 mg g−1, 81.3 mg g−1 and 133.0 mg g−1 for Ga3+, In3+ and Tl3+, respectively. The preconcentration factor is 200 and the limits of detection of Ga3+, In3+ and Tl3+ are 4.10 μg L−1, 1.55 μg L−1 and 1.21 μg L−1, respectively. Interference by Al3+ can be masked by the addition of F−; and that of Fe3+ by its reduction to Fe2+ using 10% ascorbic acid. The method was successfully applied for the determination of these ions in water, sediments and liquid crystal display samples.

New series of metal complexes of Co(II), Ni(II), Cu(II), Zn(II), Pd(II) and Pt(II) with 4-(p-chlorophenyl)-1- (pyridin-2-yl)thiosemicarbazide (HCPTS) have been synthesized and characterized by elemental analyses, magnetic moment, spectra (IR, UV-Vis, 1 H NMR, mass and ESR) and thermal studies. The IR data suggest different coordination modes for HCPTS which behaves as a monobasic bidentate with all metal ions except Cu(II) and Zn(II) which acts as a monobasic tri- dentate. Based on the electronic and magnetic studies, Co(II), Cu(II), Pd(II) and Pt(II) complexes have square - planner, Ni(II) has mixed stereochemistry (tetrahedral + square planar), while Zn(II) is tetrahedral. Molar conductance in DMF solution indi- cates the non-ionic nature of the complexes. The ESR spectra of solid copper(II) complex show g|| (2.2221) >g⊥ (2.0899) > 2.0023 indicating square-planar structure and the presence of the unpaired electron in the dx2−y2 orbital with significant cova- lent bond character. The thermal stability and degradation kinetics of the ligand and its metal complexes were studied by TGA and DTA and the kinetic parameters were calculated using Coats-Redfern and Horowitz-Metzger methods. The complexes have more antibacterial activity against some bacteria than the free ligand. However, the ligand has high anticancer activities against HCT116 (human colon carcinoma cell line) and HEPG2 (human liver hepatocellular carcinoma cell line) compared with its complexes.

2-(pyridine-2-yl)-N-p-chlorohydrazinecarbothioamide (HCPTS) was synthesized, characterized and successfully applied for the preconcentration of Cu(II), Ni(II), Zn(II), Cd(II), Co(II), Pb(II), Fe(II), and Hg(II) in water, blood, and urine samples prior to graphite furnace atomic absorption determination (GFAAS); Hg was determined by cold vapor technique. Under the optimum experimental conditions (i.e. pH = 8, 10–4 M of HCPTS, 0.05% w/v of Triton X-114), calibration graphs were linear in the range of 0.02 to 200 ng?mL–1 for Co(II), Cd(II), Pb(II) and Ni(II); 0.03 to 200 ng?mL–1 for Cu(II); 0.07 to 200 ng?mL–1 for Fe(II) and Zn(II) and 0.02 to 150 ng?mL–1 for Hg(II). The enrichment factors were 43, 51, 41, 46, 54, 40, 45 and 52 for Cu(II), Ni(II),Zn (II), Cd(II), Co(II), Pb(II), Fe(II), and Hg(II), respectively. The limit of detection were found to be 0.019, 0.094, 0.0514, 0.052, 0.0165, 0.047, 0.068 and 0.041 ng?mL–1 for Cu(II), Ni(II), Zn(II), Cd(II), Co(II), Pb(II), Fe(II), and Hg(II), respectively. The developed method was applied to the determination of these metal ions in water, blood and urine samples with satisfactory results.

Cadmium (Cd) level in blood and urine of soldering iron workers (n=49) and 41 matched healthy controls has been assessed. Cloud point extraction was employed for preconcentration of Cd. The Cd ions formed hydrophobic complex with 9,10-phenanthraquinone monoethyl thiosemicarbazone that was extracted by surfactant-rich phases in the nonionic surfactant Triton X-114. The surfactant-rich phase was diluted with 1 M HNO3 in methanol prior to its analysis by graphite furnace atomic absorption spectrometry. The parameters affecting the extraction efficiency of the proposed method, such as solution pH, amount of complexing agent, surfactant concentration, temperature, and incubation time, were optimized. Under the optimum experimental conditions, the detection limit and the enrichment factor were 0.04 μg L(-1) and 61, respectively. Relative standard deviation of 10 μg L(-1) Cd was less than 3.0%. The accuracy of the method was examined by analysis of certified reference materials. It was observed that soldering iron workers are liable to Cd overload as indicated by higher levels of Cd in blood and urine when compared with the controls. This exposure may lead to kidney damage indicated by elevation of urinary excretion of both N-acetyl-β-D-glucosaminidase and β2-microglobulin.

Hydroxyapatite nanorods (HAPNRs) were prepared from recycled eggshell by using precipitation method. The structure of the HAPNRs was physicochemically and morphologically characterized by X-ray diffraction, transmission electron microscopy and Fourier transform infrared spectroscopy. The resulting HAPNRs were used for solid phase extractive preconcentration of Cu(2+), Zn(2+) and Pb(2+) prior to its determination by flame atomic absorption spectrometry. Experimental variables that influence the quantitative extraction of metal ions were optimized by both batch and column methods. The analytes were quantitatively sorbed on the matrix between pHs6 and 9. The maximum sorption capacity of the HAPNRs has been found to be 2.43, 2.37 and 2.53 mmol g(-1) for Cu(2+), Zn(2+) and Pb(2+), respectively, with the preconcentration factor of 250. The 3σ detection limit and 10σ quantification limit for Cu(2+), Zn(2+) and Pb(2+) were found to be 0.72, 0.55 and 5.12 μg L(-1) and 2.40, 1.83 and 17.06 μg L(-1), respectively. The calibration curves were linear up to 250 μg L(-1) for Cu(2+), 300 μg L(-1) for Zn(2+) and 400 μg L(-1) for Pb(2+). Accuracy of the proposed method was verified using certified reference materials (NCS ZC85006 Tomato, Seronorm Trace Elements Whole Blood L-1, Seronorm Trace Elements Whole Blood L-3 and Seronorm Trace Elements Urine). The present method was successfully applied to the analysis of these metal ions in sea water, biological and food samples.