The voluntary control of heart rate under differential somatic restraint

The effect of chlorothiazide on the pharmacokinetics of lithium in both plasma and RBCs was studied in normal adult males. This was accomplished by administering single, 300 mg. doses of lithium carbonate alone and concurrently with chlorothiazide (0.5 grams/day for one week). Thiazide administration resulted in increases in plasma and RBC concentrations of 26.2 and 25.4%, respectively, as well as a 26.5% decrease in renal lithium clearance. The data were analyzed in terms of a two compartment pharmacokinetic model as previously reported (8). The results of this analysis showed that the change in renal lithium clearance could be accounted for by a 24.1% reduction in the value of ke, the excretion rate constant. It was also shown that changes in plasma lithium concentration during chronic lithium therapy would be expected to increase by 25-30% when chlorothiazide therapy is employed. The model also predicts that changes in RBC concentrations would parallel those occurring in plasma and thus no change in the RBC/plasma lithium ratio would be expected.     

Pharmacokinetics of lithium in human plasma and erythrocytes

The time course of lithium concentration in plasma and RBCs was measured in normal adult males following administration of single and multiple doses of lithium carbonate. From the single dose profiles, it was determined that lithium distribution between plasma and RBCs is not a simple partitioning phenomenon. The single dose time course measurements in both blood components were fit to a two compartment pharmacokinetic model in which the plasma was representative of the central compartment and the RBCs were representative of the tissue compartment. The importance of correction for trapped plasma volume in studies measuring lithium RBC kinetics was emphasized. In this study it was also demonstrated that one can accurately predict plasma and RBC lithium concentrations which are observed following multiple dosing, on the basis of single dose parameters obtained in the same subject.     

The lithium ratio and the incidence of side effects

1. During a prospective and outpatient study the correlation between the lithium ratio and the incidence of lithium side effects and type of comedications was studied in 51 Iranian bipolar patients by using new direct method of measuring erythrocyte lithium concentration. 2. Results revealed that patients who received lithium alone the incidence of lithium side effects was extremely lower than those with lithium and neuroleptics in combination. Both neurological and renal side effects of lithium were higher in patients who received lithium in combination with neuroleptics. 3. In patients on lithium alone the lithium ratio among patients with side effects were significantly lower than those without side effects, and the plasma lithium concentrations were significantly higher in those with side effects. In patients who received neuroleptics in combination with lithium, the lithium ratios were also significantly lower in those with serious side effects than those with slight side effects, but there were no significant correlation in plasma lithium concentrations between them. 4. Previous studies about the correlation of the lithium ratio and incidence of side effects have yielded inconsistent results, and methodological problems may be a reason for these discrepancies. By using the new direct method of measuring erythrocyte lithium concentration, repetition of previous studies on lithium ratio may elucidate its value as a tool in daily practice.     

Competition between Li+ and Mg2+ for the phosphate groups in the human erythrocyte membrane and ATP: an NMR and fluorescence study

We investigated the mechanism of competition between Li+ and Mg2+ in Li(+)-loaded human red blood cells (RBCs) by making 7Li and 31P NMR and fluorescence measurements. We used 7Li NMR relaxation times to probe Li+ binding to the human RBC membrane and ATP; an increase in Mg2+ concentration caused an increase in both 7Li T1 and T2 values in packed Li(+)-loaded RBCs, in suspensions of Li(+)-loaded RBC ghosts, in suspensions of Li(+)-containing RBC membrane, and in aqueous solutions of ATP, indicating competition between Li+ and Mg2+ for binding sites in the membrane and ATP. We found that increasing concentrations of either Li+ or Mg2+ in the presence of human RBC membrane caused an increase in the 31P NMR chemical shift anisotropy parameter, which describes the observed axially symmetric powder pattern, indicating metal ion binding to the phosphate groups in the membrane. Competition between Li+ and Mg2+ for phosphate groups in ATP and in the RBC membrane was also observed by both fluorescence measurements and 31P NMR spectroscopy at low temperature. The ratio of the stoichiometric binding constants of Mg2+ to Li+ to the RBC membrane was approximately 20; the ratio of the conditional binding constants in the presence of a free intracellular ATP concentration of 0.2 mM was approximately 4, indicating that Li+ competes for approximately 20% of the Mg(2+)-binding sites in the RBC membrane. Our results indicate that, regardless of the spectroscopic method used, Li+ competes with Mg2+ for phosphate groups in both ATP and the RBC membrane; the extent of metal ion competition for the phosphate head groups of the phospholipids in the RBC membrane is enhanced by the presence of ATP. Competition between Li+ and Mg2+ for anionic phospholipids or Mg(2+)-activated proteins present in cell membranes may constitute the basis of a general molecular mechanism for Li+ action in human tissues.     

Current mastitis problems in the U.S.A]

62 patients with affective disorder, 31 unipolar, 22 bipolar and 9 cycloid psychotics who had received prophylactic lithium therapy for 0,3 to 7,5 years were studied. Lithium in plasma, lithium in red blood cells (RBC) and the lithium ratio (RBC/plasma) were estimated. The lithium ratio does not seem to be of predictive value in determining for which patients prophylactic lithium therapy will succeed.     

Lithium-magnesium relationship in red blood cells during lithium prophylaxis

The authors investigated lithium and magnesium levels in serum and RBC in 30 patients with affective disorders during lithium prophylaxis. No differences in magnesium levels were found in relation to diagnosis (unipolar, bipolar), sex and age. Mean RBC lithium index was higher in females than in males, particularly in bipolar patients. Magnesium levels in erythrocytes showed a significant negative correlation with RBC lithium and RBC lithium index. Serum magnesium levels did not correlate of lithium concentrations. It was concluded that RBC magnesium may play a role in lithium penetration of RBC and this was discussed in relation to clinical and pathogenetic factors.     

Treatment failure and methadone dose in a public methadone maintenance treatment programme in Geneva

PURPOSE: To determine the effect of an anaesthetic with antioxidant potential, propofol, on red blood cell (RBC) antioxidant enzyme activities and RBC susceptibility to peroxidative challenge. METHODS: Propofol was administered by intravenous bolus (2.5 mg.kg-1) and continuous infusion (36 and 72 ml.hr-1 in nine swine; 216 ml.hr-1 in two swine), to achieve serum concentrations between 5 and 30 micrograms.ml-1 for two hours at each rate. Arterial blood sampling was at 0, 10, 30, 60, and 120 min for each rate of infusion, for measurement of plasma propofol concentration, activities of plasma and RBC superoxide dismutase, glutathione peroxidase, glutathione reductase, RBC catalase, and RBC malondialdehyde (MDA) formation in response to ex vivo oxidative challenge with t-butyl hydrogen peroxide (tBHP; 1.5 mM). Antioxidant mechanisms were determined by in vitro study of MDA formation, GSH depletion, and oxidation of haemoglobin to methaemoglobin in human erythrocytes exposed to propofol 0-75 microM. The antioxidant potential of propofol was compared with that of alpha-tocopherol utilising the reaction with 2,4,6-tripyridyl-s-triazine (TPTZ). RESULTS: Propofol had no effect on plasma or RBC antioxidant enzyme activities. It inhibited RBC MDA production over the range of 0-20 micrograms.ml-1 (y = -18.683x + 85.431; R2 = 0.8174). Effective propofol concentrations for 25% and 50% reductions in MDA levels were 7-12 and 12-20 micrograms.ml-1, respectively. Propofol has a similar effect on human erythrocytes in vitro (R2 = 0.98). CONCLUSION: Propofol antagonises the effects of forced peroxidation of red cells at anaesthetic and sub-anaesthetic concentrations in swine. Its actions include scavenging of oxygen derived free radicals in a tocopherol-like manner.     

Regional perfusion and oxygenation of tumors upon methylxanthine derivative administration

PURPOSE: The use of methylxanthine derivatives has been postulated as a means of increasing tumor perfusion and thus ameliorating tumor hypoxia. The aim of this study was to quantify and compare the effects of three methylxanthine derivatives: pentoxifylline (PX), torbafylline (TB), and HWA 138 (HW) on tumor perfusion and oxygenation. METHODS AND MATERIALS: Anesthetized Sprague Dawley rats with DS-sarcomas implanted subcutaneously onto the hind foot dorsum were used in this study. Mean arterial blood pressure (MABP) was measured throughout experiments. Regional red blood cell (RBC) flux was monitored using a multichannel laser Doppler device and tumor oxygenation on a more global level was assessed polarographically using an O2-sensitive catheter electrode. The methylxanthine derivatives were administered as a single dose intraperitoneally (for PX 50 mg/kg; for TB and HW 75 mg/kg). RESULTS: Following drug administration, initial decreases in MABP down to 75% of baseline values were observed for all three substances. PX, HW, and TB caused initial transient reductions in mean RBC flux followed by gradual increases to values of 137 +/- 27%, 139 +/- 14%, and 122 + 14% respectively at t = 60 min. Following a small initial decrease upon drug administration, O2 partial pressure (pO2) rose to 160 +/- 31%, 153 +/- 34%, and 121 +/- 11% for PX, HW, and TB, respectively at t = 60 min. At the end of the observation period (t = 90 min), increases in RBC flux and pO2 were still evident. When individual tumors were considered, a variety of patterns (including opposing effects) for changes in RBC flux were seen, not necessarily reflected in the mean values. Thus, while the methylxanthine derivatives caused an increased average tumor perfusion, there is evidence suggesting that a redistribution of tumor blood flow occurs which may amplify preexisting heterogeneity. CONCLUSIONS: Substantial improvements in tumor oxygenation and perfusion were observed after administration of the methylxanthine derivatives. These substances may therefore be of use during tumor therapies in which the outcome may be detrimentally affected by the presence of hypoxia.     

Properties of the Ca2+ influx reveal the duality of events underlying the activation by vanadate and fluoride of the Gárdos effect in human red blood cells

The properties of the 45Ca2+ influx by human red blood cells (RBC) induced by NaVO3 or NaF were compared. The NaVO3-induced 45Ca2+ influx was slower and less extensive than that induced by NaF. Both processes were saturable with Ca2+. Substitution of Na+ by K+ inhibited the 45Ca2+ influx induced by NaVO3 but stimulated that by NaF. The NaVO3-induced Ca2+ influx was sensitive to nifedipine (IC50 = 50 mol/l), Cu2+ (IC50=9 mol/l), DTNB (5,5'-dithiobis-(dinitrobenzoic acid)) (IC50 = 12 mol/l) (maximal inhibition 16%, 18%, and 28%, respectively, if NaF was used as inducer). On the other hand, tetrodotoxin (TTX) and cyclosporin A inhibited only the NaF-induced 45Ca2+ influx (IC50 = 21 mol/l and 28 mol/l, respectively). Pig RBC, known not to display the NaVO3-induced Ca2+ influx, exhibited Ca2+ influx induced by NaF. The results show that NaVO3 activates the Ca2+ influx via a pathway homologous to the L-type Ca2+ channel while the NaF-induced Ca2+ influx is mediated via the TTX-sensitive Na+ channel in the presence of NaF with possible participation of calcineurin or cyclophilin. Thus, the Gardos effect induced by NaVO3 and NaF represents two phenomena activated by different mechanisms present in the cryptic state in the RBC membrane.     

Effect of hydrochlorothiazide therapy on the crystallization of calcium oxalate in urine

1 We examined the case notes of 82 psychiatric out-patients (aged 21-84 years) receiving lithium prophylaxis and with steady-state plasma lithium levels. 2 The mean weight-related daily dose of lithium prescribed decreased by about 50% between the third and eight decades. 3 The corresponding steady-state plasma lithium levels showed a less marked tendency to decrease, this only being seen in the seventh and eighth decades. 4 In patients aged 50 years or over the daily lithium dose required to give a plasma level of 1 mmol l-1 (0.50 mmol kg-1) was significantly lower than that (0.65 mmol kg-1) in patients aged under 50 years (P less than 0?5, Student's t-test). In patients aged 70-79 years this dose was 31% lower than in patients under 50 years. However, interindividual variation was great and it was estimated that age only contributed about 14% to the total interpatient variation. 5 Of the 36 patients under 50 years of age, 42% had minor lithium side-effects and 17% were not optimally controlled with lithium. The corresponding figures for the 46 'older' patients were 46% and 28%. 6 Generally the 50% dosage reduction seemed necessary to compensate for an age-related decrease in lithium excretion and to reduce lithium side effects to a level comparable to that acceptable in younger patients.     

Prenatal ultrasonographic diagnosis of the cerebro-costo-mandibular syndrome: case report and review of the literature

Oxethazaine (OXZ), a potent topical anesthetic, was found to induce red blood cell (RBC) lysis in vitro, depending upon concentrations of OXZ, RBC and Ca2+. In a 2% RBC suspension, 100 microM OXZ caused almost complete hemolysis in the presence of 1.3 mM Ca2+ with only a minimal effect in its absence, while higher concentrations of OXZ (400 microM<) produced hemolysis without Ca2+. The hemolysis induced by OXZ plus Ca2+ was preceded by a rapid increase in 45Ca2+ uptake by RBCs, with both the hemolysis and Ca2+ uptake being inhibited by 1 mM CoCl2, NiCl2, and quinine. Together with the Ca2+ influx, rapid influx of Na+ and efflux of K+ occurred, and an increasing external K+/Na+ concentration ratio inhibited both hemolysis and Ca2+ influx. Morphologically, OXZ plus Ca2+ caused rapid transformation to spheroechinocytes, the formation of blebs and the pinching-off of blebs, whereas OXZ alone produced membrane invagination. SDS-PAGE analysis of the ghosts prepared from the RBCs treated with OXZ plus Ca2+ revealed derangement of cytoskeletal components. OXZ is a rare drug that exhibits a Ca2+ ionophore-like action, increasing the Ca2+ permeability of plasma membranes.     

Lactate distribution in the blood during steady-state exercise

PURPOSE: The purpose of this investigation was to examine the plasma to red blood cell (RBC) lactate concentration ([La]) gradient and RBC:plasma [La] ratio during 30 min of steady-state cycle ergometer exercise at work rates below lactate threshold ( LT. Blood samples were taken from a heated forearm vein, immediately cooled to 4 degrees C in a dry-ice ethanol slurry, and centrifuged at 4 degrees C to separate plasma and RBCs. RESULTS: During >LT, plasma [La] rose to 8.8+/-1.1 mM after 10 min and remained above 6 mM. RBC [La] (4.9+/-0.7 mM) was significantly lower than plasma [La] at 10 min and remained lower throughout exercise. As a result, there was a sizable [La] gradient (approximately 3.5 mM) from plasma to RBC during most of >LT. In LT, the ratio of RBC [La]:plasma [La] was the same for both (0.58+/-0.02) and not significantly different from rest. CONCLUSIONS: These results refuted our hypothesis that the RBC:plasma [La] ratio would decrease at the onset of >LT exercise because of muscle lactate release exceeding the ability of RBCs to take up the lactate. Instead, there appears to be an equilibrium between plasma [La] and RBC [La] in arterialized venous blood from a resting muscle group as evidenced by the constant RBC [La]:plasma [La] ratio.     

Lithium neurotoxicity at low therapeutic doses Hypotheses for causes and mechanism of action following a retrospective analysis of published case reports

Lithium has been the pharmacologic treatment for the management of manic-depressive illness for many years. While the therapeutic efficacy of lithium is invaluable, it can cause a variety of neurotoxicities at normal therapeutic doses or concentrations. A systematic search through the Medline database was performed. 41 Cases of neurotoxic adverse effects of lithium at low therapeutic concentrations were observed (< 65 years, 14 males & 21 females/> 65 years, 6 females). Although a higher percentage of female subjects experienced lithium neurotoxicity, no statistically significant difference between the two groups was noted (Fisher's exact test, P = 0.07). The analysis of the data shows that among case reports of lithium neurotoxicity, drug interaction effect is an important factor. More than 50% (51.2%) of the patients received at least one neuroleptic medication with their lithium treatment, 22% received concomitantly an antidepressant, 22% an antiepileptic (carbamazepine) and 17% an anxiolytic. It is our hypothesis that these drug associations are an important contributing factor to lithium neurotoxicity. The high percentage of neurotoxicity which is associated with neuroleptics warrant caution in the daily clinical practice when these two classes of medications are combined. It is hypothesised that neuroleptics, in particular the phenothiazines, might increase lithium influx in red blood cells and that the enhanced levels of lithium in the tissue may possibly be responsible for the neurotoxic effects. Concomitant administration of medications such as neuroleptics with lithium require caution with regular clinical observations and drug plasma concentration monitoring.     

Determination of the active moiety of BX661A, a new therapeutic agent for ulcerative colitis, by studying its therapeutic effects on ulcerative colitis induced by dextran sulfate sodium in rats

Conventional hematopoietic stem cell cryopreservation methods use a DMSO concentration of 10%. However, cells manipulated ex vivo may require more refined freezing protocols adapted to the specific cell suspension. In this retrospective study, we evaluated the results obtained with CD34+ cells purified from peripheral blood of 39 patients on the CEPRATE SC System and frozen in 7.5% DMSO with a view to transplantation. The post-freezing recovery of progenitor cells was 89.4 +/- 27.87% for CD34+ cells, 59.13 +/- 36.93% for CFU-GM, and 53.49 +/- 40.71 for BFU-E. Neither the purity of the suspension nor the nucleated cell density during freezing was predictive of cell recovery. No difference was observed between cells stored in vials and bags. Thirty-seven patients transplanted with the concentrated CD34+ fraction received 4.46 x 10(6) CD34+ cells/kg and 33.04 x 10(4) CFU-GM/kg. The median time to granulocyte (>0.5 x 10(9)/l) and platelet (>50 x 10(9)/l) engraftment was 11 and 13 days, respectively. Only cell density and the infused number of CD34+ cells and CFU-GM were significantly related to hematological recovery. Our data suggest that purified CD34+ cells can be successfully cryopreserved in 7.5% DMSO and may represent a first step in establishing freezing parameters for selected CD34+ cells.     

Salt Inhibition Effects in Biological Treatment of Saline Wastewater in RBC

Design and operation of saline wastewater treatment systems are difficult because of adverse effects of salt on microbial flora. Quantification and modeling of salt inhibition effects are essential in designing biological treatment processes for saline wastewater. Synthetic wastewater containing 0–10% salt (NaCl) was treated in a rotating biodisc contactor (RBC) unit operating in a continuous mode. Effects of important process variables such as the A∕Q ratio, COD loading rate, and salt concentration on COD removal rate and efficiency were investigated. The system's performance improved with an increasing A∕Q ratio; however, performance decreased with an increasing COD loading rate and salt content. The liquid phase was aerated to keep suspended cells active at high feed COD concentrations such as S0 = 5,000 mg∕L. A mathematical model was developed to describe the system's behavior. Model parameters were determined by using the experimental data. Salt inhibition was found to be significant for salt concentrations larger than 2% NaCl. The experimental results and mathematical model may be used in design of RBC units treating saline wastewater.     

An elevation of stem cell factor in patients with hyperthyroid Graves'' disease

The dose of cells expressing the surface antigen CD34 (CD34+) has been shown to be a reliable predictor of the time to engraftment following transplantation of PBPC to support high-dose chemotherapy. However, evaluation of rare cells is complicated by a number of factors, including the variability in operator and technical procedures. Recently, Becton Dickinson Immunocytometry Systems introduced a new CD34+ cell analysis system, the ProCOUNT cell enumeration kit, which automates the analysis of CD34+ cells and minimizes the variabilities of this procedure. We have evaluated the ProCOUNT system in comparison to a standard CD34 cell analysis (based on the Milan approach) using leukapheresis products from patients and normal donors mobilized with chemotherapy plus recombinant human G-CSF (rhG-CSF) or with rhG-CSF alone. In addition, we compared these analyses using CD34+ cell-selected mobilized leukapheresis products with purities of 75% or greater. The standard CD34 cell analysis methodology quantitated the frequency of cells identified as CD45+, low side scatter, and CD34+. A high correlation coefficient was obtained between the ProCOUNT methodology and the standard CD34 cell analysis methodology for cells obtained from leukapheresis products mobilized with chemotherapy plus rhG-CSF (r = 0.98), rhG-CSF alone (r = 0.96), and CD34+-selected mobilized leukapheresis products (r = 0.83). A comparison was also made between technicians using both analysis methods. Whereas the correlation coefficient between two technicians using the standard methodology was r = 0.77, the correlation coefficient was much higher when using ProCOUNT (r = 0.99). These data demonstrate that the use of ProCOUNT is associated with less variability between data analyzed by different operators. Also, ProCOUNT is consistent with existing CD34+ cellular analysis methodologies. An additional advantage is the ability to determine the absolute concentration of CD34+ cells, thereby allowing calculation of total CD34+ cell numbers without using WBC counts, which also have inherent errors. The ProCOUNT system provides an automated analysis procedure that minimizes the variables in CD34+ cell analysis and may be useful for standardization of methodology between laboratories.     

Concomitant mobilization of plasma cells and hematopoietic progenitors into peripheral blood of multiple myeloma patients: positive selection and transplantation of enriched CD34+ cells to remove circulating tumor cells

One advantage of the use of peripheral blood stem cells (PBSCs) over autologous bone marrow would be a reduced risk of tumor cell contamination. However, the level of neoplastic cells in the PB of multiple myeloma (MM) patients after mobilization protocols is poorly investigated. In this study, we evaluated PB samples from 27 pretreated MM patients after the administration of high dose cyclophosphamide (7 g/m2 or 4 g/m2) and granulocyte-colony stimulating factor for the detection of myeloma cells as well as hematopoietic progenitors. Plasma cells containing intracytoplasmic lg were counted by microscope immunofluorescence after incubation with appropriate antisera directed against light- and heavy-chain lg. Moreover, flow cytometry studies were performed to determine the presence of malignant B-lineage elements by using monoclonal antibodies against the CD19 antigen and the monotypic light chain. Before initiation of PBSC mobilization, circulating plasma cells were detected in all MM patients in a percentage ranging from 0.1% to 1.8% of the mononuclear cell fraction (mean value, 0.7% +/- 0.4% SD). In these patients, a higher absolute number of PB neoplastic cells was detected after chemotherapy and granulocyte colony-stimulating factor. Kinetic analysis showed a pattern of tumor cell mobilization similar to that of normal hematopoietic progenitors with a maximum peak falling within the optimal time period for the collection of PBSCs. The absolute number of plasma cells showed a 10 to 50-fold increase as compared with the baseline value. Apheresis products contained 0.7% +/- 0.2% SD of myeloma cells (range, 0.2% to 2.7%). Twenty-three MM patients were submitted to PBSC collection. In 10 patients, circulating hematopoietic CD34+ cells were highly enriched by avidin-biotin immunoabsorption, were cryopreserved, and used to reconstitute bone marrow function after myeloablative therapy. The median purity of the enriched CD34+ cell population was 89.5% (range, 51% to 94%), with a 75-fold increase as compared with the pretreatment samples. The median overall recovery of CD34+ cells and colony-forming unit-granulocyte-macrophage was 58% (range, 33% to 95%) and 45% (range, 7% to 100%), respectively. Positive selection of CD34+ cells resulted in 2.5- to 3-log depletion of plasma cells and CD19+ B-lineage cells as determined by immunofluorescence studies, although DNA analysis of CDR III region of IgH gene showed the persistence of minimal residual disease in 5 of 6 patient samples studied. Myeloma patients were reinfused with enriched CD34+ cells after myeloablative therapy consisting of total body irradiation (1,000 cGy) and highdose melphalan (140 mg/m2). They received a median of 4 x 10(6) CD34+ cells/kg and showed a rapid reconstitution of hematopoiesis; the median time to 0.5 x 10(9) neutrophils and to 20 and 50 x 10(9) platelets per liter of PB was 10, 11, and 12 days, respectively. These results, as well as other clinically significant parameters, did not significantly differ from those of patients (n = 13) receiving unmanipulated PBSCs after the same pretransplant conditioning regimen. In summary, our data show the concomitant mobilization of tumor cells and hematopoietic progenitors in the PB of MM patients. Positive selection of CD34+ cells reduces the contamination of myeloma cells from the apheresis products up to 3-log and provides a cell suspension capable of restoring a normal hematopoiesis after a total body irradiation-containing conditioning regimen.     

电感耦合等离子体原子发射光谱-实时内标法测定锂电池三元正极材料中主量元素

锂电池正极材料中镍、钴、锰元素的物质的量占比对锂电池性能有较大影响,而使用电感耦合等离子体原子发射光谱法测定其物质的量占比时,存在数据波动大、稳定性差导致无法精确计算等问题。实验使用电感耦合等离子体原子发射光谱(ICP-AES),并采用实时内标法(Real-Time Internal Standardization,RTIS)测定锂电池三元正极材料中主量元素镍、钴、锰。通过实时内标法将样品中待测元素镍、钴、锰与内标元素钇在同一个时间测定从而消除进样系统噪音、等离子体稳定性等对结果产生的影响。按照实验方法测定4个锂电池三元正极材料中镍、钴、锰的物质的量占比,结果的相对标准偏差(RSD,n=3)不大于0.1%;各元素重复测定的绝对偏差绝对值为0.0001%~0.0223%;各元素2h连续测定的结果的相对标准偏差(RSD,n=8)为0.038%~0.099%。     

电感耦合等离子体原子发射光谱-实时内标法测定锂电池三元正极材料中主量元素

锂电池正极材料中镍、钴、锰元素的物质的量占比对锂电池性能有较大影响,而使用电感耦合等离子体原子发射光谱法测定其物质的量占比时,存在数据波动大、稳定性差导致无法精确计算等问题。实验使用电感耦合等离子体原子发射光谱(ICP-AES),并采用实时内标法(Real-Time Internal Standardization,RTIS)测定锂电池三元正极材料中主量元素镍、钴、锰。通过实时内标法将样品中待测元素镍、钴、锰与内标元素钇在同一个时间测定从而消除进样系统噪音、等离子体稳定性等对结果产生的影响。按照实验方法测定4个锂电池三元正极材料中镍、钴、锰的物质的量占比,结果的相对标准偏差(RSD,n=3)不大于0.1%;各元素重复测定的绝对偏差绝对值为0.0001%~0.0223%;各元素2h连续测定的结果的相对标准偏差(RSD,n=8)为0.038%~0.099%。     

萃取法从废旧锂离子电池正极材料 浸出液中提取锂

废旧锂离子电池正极材料浸出后，溶液中的镍、钴等有价金属十分容易回收，但一直没有很好的方法来回收锂.实际上，这种浸出液和盐湖卤水都为锂盐溶液，所不同的只是盐湖卤水中锂的浓度往往要低一些，并有大量的氯化钠、氯化镁伴生，因此可将废旧锂离子电池浸出液看做一种特殊的“盐湖卤水”，并进一步调整其Cl－的浓度，进而成功地采用盐湖提锂中常用的萃取法.该方法以磷酸三丁酯（TBP）为萃取剂，磺化煤油为稀释剂，在三氯化铁（FeCl₃）存在的条件下，实现选择性提取锂. TBP首先与FeCl₃-NaCl的酸性溶液接触, 形成了锂的专属萃取剂；并将浸出液中氯化钠的浓度进一步调整到250 g/L，在相比（V_O/V_A）为3，温度为室温条件下萃取5 min, 锂的单级萃取率可达到75 %左右，而Ni2+、Co2+、Mn2+几乎没有被萃取.根据平衡等温线，通过4级逆流萃取，锂的萃取率可达到99 %.