Ppb Of Cr Research Articles

Punica grantum peel extract decorated Al-MOF scaffold as Solid-State Sensor/Concentrator for the Sensing/Reduction of Cr(VI) and its extended utility as a corrosion inhibitor in Al-Air batteries

The growing presence of hexavalent chromium in environmental and industrial settings highlights the importance of developing an eco-benign platform for real-time in-situ sensing/screening and decontamination. This research presents a facile and portable solid-state optical sensor using waste Punica Granatum, i.e., pomegranate peel extract (PPE) adorn onto Aluminium-based Metal-Organic Frameworks (Al-MOFs) for the sensing of carcinogenic Cr(VI) and its decontamination to benign Cr(III). The sensor fabrication entails a hydrothermal synthesis to form Al-MOF scaffolds decorated with PPE through direct immobilization. Al-MOF exhibits a large surface area with well-defined pore channels that facilitate PPE’s voluminous/uniform anchoring in restricted orientations to serve as an ion-selective probe for specifically targeting ultra-trace Cr(VI). The surface/structural morphology and porosity of the Al-MOF-PPE material are characterized using scanning/transmission electron microscopy and BET/BJH analysis. The reduction of Cr(VI) by the Al-MOF-PPE is validated by electron spectroscopy for chemical analysis, corroborated by a conspicuous color transition from light yellow to dark brown. The efficient reduction of Cr(VI) by Al-MOF-PPE is achieved at pH 2–3, in the linear response range of 0.3–300 ppb and a detection limit of 0.23 ppb for Cr(VI). The sensory system prefers minimal PPE probe content (4 mg) and sensor dosage (5 mg) for ion-sensing and decontamination studies, highlighting its remarkable operational efficacy. Post Cr(VI) reduction, electrochemical studies confirm the utility of Al-MOF-PPE-Cr(III) as a corrosion inhibitor for metal surfaces. Tafel plots demonstrate that Al-MOF-PPE-Cr(III) exhibits cathodic and anodic inhibition characteristics, ensuring excellent surface protection for aluminum electrodes upto 220 min in Al-air batteries. The proposed Al-MOF-PPE offers dual functionality as a naked-eye platform for Cr(VI) decontamination, and the Al-MOF-PPE-Cr(III) material is an excellent corrosion inhibitor for energy storage devices.

Metal levels and glomerular filtration rate after unilateral Birmingham Hip Resurfacing.

The first aim of this study was to evaluate whether preoperative renal function is associated with postoperative changes in whole blood levels of metal ions in patients who have undergone a Birmingham Hip Resurfacing (BHR) arthroplasty with a metal-on-metal bearing. The second aim was to evaluate whether exposure to increased cobalt (Co) and chromium (Cr) levels for ten years adversely affected renal function. As part of a multicentre, prospective post-approval study, whole blood samples were sent to a single specialized laboratory to determine Co and Cr levels, and the estimated glomerular filtration rate (eGFR). The study included patients with 117 unrevised unilateral BHRs. There were 36 females (31%). The mean age of the patients at the time of surgery of 51.3 years (SD 6.5), and they all had preoperative one-, four-, five-, and ten-year laboratory data. The mean follow-up was 10.1 years (SD 0.2). Median Co levels at one year postoperatively increased significantly compared with the preoperative values, by a factor of 9.7, from 0.13 to 1.26 ppb (p < 0.001), and the median Cr levels increased significantly by a factor of 2.5, from 0.60 to 1.50 ppb (p < 0.001). Lower preoperative eGFRs were associated with significantly larger increases in Co at one year compared with the preoperative levels (ρ = -0.26; p = 0.005), but there was no relationship between preoperative eGFRs and changes in Cr at one year (ρ = -0.13; p = 0.153). Metal levels remained relatively constant with the passage of time, with a median ten-year value of 1.12 ppb for Co and 1.29 ppb for Cr. There was no significant relationship between the Co and Cr levels at ten-year follow-up and the change in eGFR from the preoperative level to that at ten years (ρ = -0.02; p = 0.827 for Co; ρ = -0.008; p = 0.933 for Cr). Although patients with lower preoperative eGFRs tended to have larger increases in Co levels at one year, increased metal levels for patients who underwent unilateral BHR did not adversely affect renal function during the first ten postoperative years.

Immobilization of diphenylcarbazide on paper-based analytical devices for the pre-concentration and detection of chromium VI in water samples

A novel approach using a smartphone for the detection of Cr (VI) has been developed. In this context, two different platforms were designed for the detection of Cr (VI). The first one was synthesized via a crosslinking reaction of chitosan with 1,5-Diphenylcarbazide (DPC-CS). The obtained material was integrated into a paper to develop a new paper-based analytical device (DPC–CS–PAD). The DPC–CS–PAD exhibited high specificity toward Cr (VI). The second platform (DPC-Nylon PAD) was prepared by covalent immobilization of DPC onto a Nylon paper and then its analytical performances regarding Cr (VI) extraction and detection were evaluated. DPC–CS–PAD presented a linear range of 0.1–5 ppm with detection and quantification limits of about 0.04 and 0.12 ppm, respectively. The DPC-Nylon-PAD exhibited a linear response of 0.1–2.5 ppm with detection and quantification limits of 0.06 and 0.2 ppm, respectively. Furthermore, the developed platforms were effectively applied for testing the effect of the loading solution volume for trace Cr (IV) detection. For the DPC-CS material, a volume of 20 mL allowed the detection of 4 ppb of Cr (VI). In the case of DPC-Nylon-PAD, the loading volume of 1 mL permitted the detection of the critical concentration of Cr (VI) in water.

METAL LEVELS AND GLOMERULAR FILTRATION RATE AFTER BIRMINGHAM HIP RESURFACING

When the Birmingham Hip Resurfacing (BHR) metal-on-metal implant system was approved by the United States Food and Drug Administration in 2006, a multicenter, prospective, post-approval study (PAS) was required. This study uses data from the PAS to investigate metal level and glomerular filtration rate (GFR) trends over the first decade in vivo.Between October 2006 and March 2011, 290 primary BHR procedures were performed among 262 patients at 5 sites. Whole blood samples were sent to a single specialized laboratory to determine GFR, cobalt (Co) and chromium (Cr) levels. The population for this study consists of 117 unrevised unilateral patients with a mean age at surgery of 51.3±6.5 years who had pre-operative, 1-year, 4-year, 5-year and 10-year laboratory data. The mean follow-up for these patients that included 36 females was 10.1±0.2 years.Median metal levels at 1-year increased relative to pre-operative values for Co (by a factor of 9.7 from 0.13 to 1.26 ppb, p&lt;0.001) and Cr (by a factor of 2.5 from 0. 60 to 1.50 ppb, p&lt;0.001). Metal levels subsequently remained relatively constant over time with a median 10-year value of 1.12 ppb for Co and 1.29 ppb for Cr. Based on 585 blood samples from all 117 patients, there was no relationship between GFR and Co (→=−0.06, p=0.14) or Cr (→=0.05, p=0.27) levels. However, lower pre-operative GFR values were associated with larger increases in Co at 1-year relative to the pre-operative level (→=−0.26, p=0.005). There was no relationship between pre-operative GFR values and changes in Cr at 1 year (→=−0.13, p=0.15).Through the first decade in vivo, elevated whole blood metal levels for unilateral BHR patients do not appear to adversely affect GFR. However, patients with lower pre-operative GFR values tend to have larger increases in their Co level at 1-year.

Gold-silver nanoparticles modified electrochemical sensor array for simultaneous determination of chromium(III) and chromium(VI) in wastewater samples

The oxidation state of ions is a crucial aspect that often has been overlooked when determining the toxicity of chromium (Cr) species in environmental samples. In this study, a novel electrochemical sensor array based on gold-silver nanoparticles modified electrodes was developed for simultaneous determination of the two main chromium species (Cr(III) and (VI)). Specifically, the working electrodes of screen-printed carbon electrodes (SPCEs) were modified with silver-gold bimetallic nanoparticles through electrochemical deposition for detection of Cr(VI). The silver-gold bimetallic nanoparticles were further oxidized to form stable silver-gold bimetallic oxide nanoparticles for the detection of Cr(III). The results showed that the addition of silver with a theoretical value of 1% of gold could contribute to the formation and stabilization of oxides on the surface of gold nanoparticles. After characterization, the two kinds of electrodes were integrated as an electrochemical sensor array for selective and sensitive detection of Cr(VI) and Cr(III). The linear range and limit of detection (LOD, identified by three times of signal-to-noise ratio) were found to be 0.05–5 ppm and 0.1 ppb for Cr(VI), and 0.05–1 ppm and 0.1 ppb for Cr(III), respectively. Finally, the electrochemical sensor array was proven for successful detection of Cr(VI) and Cr(III) in tap water, artificial saliva and artificial sweat samples, and monitoring of Cr(VI) and Cr(III) in chromium-containing wastewater treatment process. Combined with a handheld dual-channel electrochemical device, the simultaneous determination of Cr(VI), Cr(III) and total chromium contents can be easily achieved for various samples.

Establishing thresholds for metal ion levels in patients with bilateral Articular Surface Replacement hip arthroplasty.

The primary aim of the current study was to determine whether metal ion levels could identify well- from poorly-functioning implants in patients after undergoing bilateral Articular Surface Replacement (ASR) Hip System. The secondary aim was to establish threshold values for Co and Cr that could be used to predict clinical problems in these patients. The study included 125 patients treated with bilateral ASR hip resurfacing (HRA) and 93 patients treated with bilateral ASR XL total hip arthroplasty (THA) at a mean follow-up of 7.1 years post-surgery. Patients were labelled as well- or poorly-functioning based on strict criteria. We calculated the Co and Cr safe upper ion limits (SUL) for ASR HRA and ASR XL THA separately and assessed these cutoffs ability to predict clinical problems. In patients with bilateral ASR HRA, the well-functioning group had lower ions than the poorly-functioning. In ASR THA patients, there was no difference in blood Co or Cr levels between well- and poorly-functioning implant groups (p = 0.118 and p = 0.379, respectively). Both Co and Cr could effectively discriminate between well-functioning and poorly-functioning ASR HRA implants (p < 0.001 and p < 0.001, respectively), but not for ASR THA implants (p = 0.118 and p = 0.564, respectively). SULs of 4.0 ppb for Co and 4.0 ppb for Cr could differentiate between well- and poorly-functioning implants with high specificity. Metal ion levels are a more reliable tool in MoM HRA than THA when discriminating well- from poorly-functioning implants in bilateral patients. For patients treated with bilateral ASR HRA, ion levels above 4.0 ppb are highly specific for the detection of clinical problems.

Major and trace element concentrations in the geothermal springs along the west coast of Maharashtra, India

The west coast geothermal province in Maharashtra hosts a number of thermal springs along the 350 km linear stretch. Major and trace element analyses of thermal springs from 15 locations along with groundwater and surface water samples have been studied. The thermal waters had temperatures ranging from 40 to 71 °C, pH from 7.1 to 8.8 and total dissolved solids between 337 and 8698 mg/l. Most of the thermal waters are Na-Ca-Cl or Ca-Na-Cl type except one which is of Na-HCO3 type. The major ion data is comparable over three decades suggesting a mature geothermal system in the west coast. Trace elements concentrations were low in case of some elements such as<0.1 ppb of Ag and Cd, 1–3 ppb of Cr, Zn, Co, Cu, Pb and Ni, whereas elements like Li (19–386 ppb), B (104–1362 ppb), Sr (16–13,560 ppb), Rb (13–220 ppb), Cs (0.75–44 ppb) and Ba (3–2077 ppb) were much higher in concentration. The variations in the trace element concentration in the thermal waters indicate involvement of different rock types although all the thermal emergences are within the Deccan volcanic flows.

Environmental implications of a hydrogeochemical survey for drinking water in Kirsehir region

A hydrogeochemical survey of springs was carried out in Kirsehir, Turkey and fluoride, heavy metals, and mineral contents were analyzed. The highest fluoride levels were detected in Mahmutlu with 2.1 ppm. The fluoride content of Pohrenk was, on average, 1.1 ppm. Consequently, dental fluorosis and dental stains were observed in both villages. Although the fluoride concentrations were within the suggested limits, dental stains and fluorosis were commonly observed among the villagers especially kids. The fluoride concentrations of 0.7–1.0 ppm were the lowest in Cevirme, which is to the northwest of fluoride ore. The heavy metal concentrations of resources around the three villages were compared with and were found lower than WHO’s provisional guideline values. However, the Fe, Zn, and Cr concentrations in hot springs were much higher than cold springs with as much as 100 ppb for Fe, 50 ppb for Zn, and 15 ppb for Cr.

EFFETS DE L'UTILISATION DE LEVURES ENRICHIES EN CHROME SUR LA PRODUCTION DU LAPIN EN CROISSANCE

The aim of this trial was to investigate the effects of high chromium Cr) yeast supplemented diets on performance of growing-finishing rabbits. Ninety-six commercial hybrid rabbits, half males and half females, aged 35 days, were divided into experimental groups and fed, ad /ibitum, for 49 days the same basal diet supplemented with 0 (T1), 400 (T2), 800 (T3) or 1600 (T 4) ppb of Cr in the form of chromium enriched yeast. Control diet (T1) was analysed and found to contain 789 ppb Cr, a level which was due to the raw feed materials. The Cr content of all the diets was then proportionally increased. Chromium supplementation did not induce any significant differences in daily weight gain (32.2 to 32.9 g/d), feed to gain ratio, hot carcass weight, dress-out percentage, kidney deposit, scapular fat deposit, or left hindleg percentage and meat/bone ratio. No differences in Cr level were observed for longissimus dorsi pH and colour. In contrast, the perirenal fat deposit was significantly higher in all rabbits which received the Cr supplementation (1.51 to 1.61 vs 1.02% of the carcass; P = 0.013) This was probably the result of a modification in lipid anabolism, in relation with the insulin activity, and particularly with the stimulation of the Growth Tolerance Factor (GTF) which contains chromium. The liver Cr percentage of T3 rabbits was significantly higher than that of control group (4.94 vs 4.30% of the carcass; P = 0.028). The authors noled a substantial lack of any practical effects of Cr supplementation on growing rabbit performance under experimental conditions.

Removal of Arsenic(III), Chromium(III) and Iron(III) Traces from Hydrofluoric Acid Solutions by Specialty Anion Exchangers

The removal of As(III), Fe(III), and Cr(III) at trace levels from HF solutions by means of specialty ion exchange resins has been investigated. These impurities are usually found in technical‐grade HF, and they need to be removed to prepare metal‐free HF for the semiconductor industry. It was assumed that Fe(III) and As(III) species in dilute HF were present in anionic form, while Cr(III) was probably in neutral form, CrF3. First, a selection of specialty ion exchangers was performed. Then, fixed‐bed experiments were carried out to check the ability of selected resins to reach the impurity levels required in SEMI C29 for 5 wt.% HF (5 ppb of As, and 10 ppb of Cr and Fe). The effect of the flow rate and the HF concentration on the metal removal was studied with Purolite D‐3777 and Fuji PEI‐CS‐07 resins respectively. Fuji PEI‐CS‐07 showed the best performance for Fe(III) removal, even at high HF concentration (25 wt.%). A strong decrease in the Cr(III) and As(III) removal capacity with increasing concentration of HF was observed.

Combining chemical reduction with an electrochemical technique for the simultaneous detection of Cr(vi), Pb(ii) and Cd(ii)

This work herein reports the approach for the simultaneous determination of heavy metal ions including cadmium (Cd(ii)), lead (Pb(ii)), and chromium (Cr(vi)) using a bismuth film electrode (BFE) by anodic stripping voltammertry (ASV). The BFE used was plated in situ. Due to the reduction of Cr(vi) with H(2)O(2) in the acid medium, on one hand, the Cr(iii) was produced and Cr(vi) was indirectly detected by monitoring the content of Cr(iii) using square-wave ASV. On the other hand, Pb(ii) was also released from the complex between Pb(ii) and Cr(vi). Furthermore, the coexistence of the Cd(ii) was also simultaneously detected with Pb(ii) and Cr(vi) in this system as a result of the formation of an alloy with Bi. The detection limits of this method were 1.39 ppb for Cd(ii), 2.47 ppb for Pb(ii) and 5.27 ppb for Cr(vi) with a preconcentration time of 120 s under optimal conditions (S/N = 3), respectively. Furthermore, the sensitivity of this method can be improved by controlling the deposition time or by using a cation-exchange polymer (such as Nafion) modified electrode.

Determination of Trace Elements in Cow's Milk in Saudi Arabia

Milk and its products are very common in our food list due to its nutrient value, since it is a source of some vitamins and a lot of mineral constituents which are necessary for proper development and functioning of different tissues and organs. However, overdose of these vitamins and mineral constituents can be harmful. This study was directed to measure the concentrations of Zinc (Zn), Cadmium (Cd), Chromium (Cr), Copper (Cu) and Lead (Pb) in cow's milk samples available commercially in Saudi Arabia using Graphite Furnace Atomic Absorption Spectrometer. Two types of milk samples were analyzed. These were - fresh cow's milk and liquid milk prepared from cow's milk powder. The mean elemental concentration values in ppb of Cr, Cu, Zn, Cd, and Pb in fresh cow's milk were: (31.4 ± 0.4), (48.9 ± 0.6), (944.9 ± 2.4), (4.7 ± 0.2) and (3.5 ± 0.2) respectively. Those in cow's milk powder were :.(20.6 ± 0.8), (36.9 ± L.l), (956.8 ± 3.2), (3.1 ± 0.3), and (2.2 ± 0.2) respectively. These values are compared with Recommended Dietary Allowance (RDA) values and also with the corresponding values of different countries available in the literature.

Effect of chromium propionate and metabolizable energy on growth, carcass traits, and pork quality of growing-finishing pigs.

An experiment was conducted to evaluate the dietary effects of Cr propionate (CrProp) and metabolizable energy (ME) on growth, carcass traits, and pork quality of growing-finishing pigs. One hundred forty-four Cambrough-22 barrows were allotted to four dietary treatments in a randomized complete block design (six replicates of six pigs per replicate; average initial and final body weight were 27 and 113 kg, respectively). The dietary treatments were: 1) corn-soybean meal basal (B; low ME), 2) B + 200 ppb of Cr (as CrProp), 3) B + 200 kcal ME/kg (4.5% added fat; high ME), or 4) B + 200 kcal ME/kg + 200 ppb of Cr. At trial termination, three pigs per replicate were killed to determine dietary effects on carcass traits and pork quality. Overall average daily gain, average daily feed intake, and gain:feed ratio were not affected (P > 0.10) by diet. During the early growing period, average daily gain was increased in pigs fed the CrProp-low-ME diets, but decreased in pigs fed the CrProp-high ME diets (Cr x ME, P < 0.04). Feed intake was increased (P < 0.05) in pigs fed the high-ME diets during the early growing period. Forty-five min and 24 h pH were not affected (P > 0.10) by diet. The CIE L* tended (P = 0.07) to be increased and shear force tended (P = 0.06) to be decreased in pigs fed high-ME diets. Subjective marbling was increased (P < 0.03) and longissimus muscle percentage moisture and thaw loss were decreased (P < 0.04) in pigs fed CrProp. Chromium propionate had no consistent effect on growth and carcass traits in this experiment; however, CrProp did affect some aspects of pork quality.

An Ultrasonic Nebulizer as the Sample Introduction Device for High Performance Liquid Chromatography Combined with Inductively Coupled Plasma Atomic Emission Spectrometry

AbstractA preliminary study of an ultrasonic nebulizer as the sample introduction device for the chromatographic speciation of ionic compounds containing As, Se and Cr is described. The analytical figures of merit observed during chromatographic separations with an ultrasonic nebulizer interfaced to an inductively coupled plasma‐atomic emission spectrometer (ICP‐AES) were comparable to or better than conventional pneumatic nebulization and other sample introduction techniques, in terms of organic solvent tolerance, sensitivity, detection limits and reproducibility. The limits of detection were in the ranges of 10‐14 ppb for Se, 30‐40 ppb for As, and 8‐10 ppb for Cr.

Distribution of minor metallic elements in river water of green tuff region, Yamagata Pref.

The concentrations of 7 minor heavy metallic elements (Cd, Cr, Cu, Mn, Ni, Pb and Zn) were determined by the A.A.S. method in 116 river water samples, of which 13 samples were collected from the granitic region and others from the green tuff region in Yamagata Prefecture. High concentration areas of the metallic elements were found in the east, southeast and central part of the survey area. In consideration of their flow rate, the mean concentrations of the metallic elements in river water were obtained. The mean values of 0.35 ppb of Cd, 3.74 ppb of Cr, 6.92 ppb of Cu, 15.39 ppb of Mn, 3.32 ppb of Ni, 5.45 ppb of Pb and 17.26 ppb of Zn were found in the green tuff region. The mean values of these elements in the granitic region was lower than that of the green tuff region except for Cr. Since it can be considered that these river water sampling sites are not affected by human activities, these values, except for lead, represent the minor metal concentration in close to its natural state.