The application of isotope dilution thermal ionization mass spectrometry to traceability of chemical measurement and interlaboratory comparisons

In this work, the method of isotope dilution thermal ionization mass spectrometry able to trace to SI was developed to accurately measure trace amount of Cd, Pb, Zn and Cu in sediment, rice, wine, and human serum samples for interlaboratory comparisons. The research focuses on how to apply the primary method correctly, uncertainty evaluation of measurement results, and how to achieve the meaning of traceability to SI by using ID-TIMS. As a result, the measurement results of Cu and Zn in the human serum 1 and 2 with 0.94, 0.83 and 0.49% combined uncertainty, respectively, were accepted by EC-JRC-IRMM as the certified values of the serum samples. The measurement results of Cd and Pb in CCQM-K13 and CCQM-K24 with 3.96, 1.62 and 1.03% combined uncertainty, respectively, are within the degrees of the equivalence. These comparisons at the highest level of measurement are proof that traceability of chemical measurement can be achieved as the traceability chain of ID-TIMS established in this work was used.     

Enrichment of low-abundant serum proteins by albumin/immunoglobulin G immunoaffinity depletion under partly denaturing conditions

We present a simple protocol for affinity depletion to remove the two most abundant serum proteins, albumin and immunoglobulin G (IgG). Under native conditions, albumin/IgG were efficiently removed and several proteins were enriched as shown by two-dimensional electrophoresis (2-DE). Besides that, partly denaturing conditions were established by adding 5 or 20% acetonitrile (ACN) in order to disrupt the binding of low-molecular-weight (LMW) proteins to the carrier proteins albumin/IgG. 2-DE results showed that the total number of detected LMW proteins increased under denaturing conditions when compared to native conditions. Interestingly, the presence of 5% ACN in serum revealed better enrichment of LMW proteins when compared to 20% ACN condition. Seven randomly distributed spots in albumin/IgG depleted serum samples under 5% ACN condition were picked from the 2-DE gels and identified by mass spectrometry (MS). The intensity of five LMW protein spots increased under denaturing conditions when compared to native conditions. Three of the seven identified spots (serum amyloid P, vitamin D-binding protein, and transthyretin) belong to a group of relatively low-abundant proteins, which make up only 1% of all serum proteins. The method presented here improves the resolution of the serum proteome by increasing the number of visualized spots on 2-D gels and allowing the detection and MS identification of LMW proteins and proteins of lower abundance.     

116例冠心病患者血清中10种必需微量元素水平的研究

１１６例冠心病患者血清中１０种必需微量元素的含量与正常值比较，具有如下特点：（１）铁，锌、铬，镍含量升高；２硒钴，钒，钼含量降低；（３）铜和锰差异无显著性。     

Enzyme co-immobilization for the sequential determination of lactic acid and glucose in serum

An enzymatic method for the sequential determination of lactic acid and glucose is proposed. Sample matrix effects are overcome by using an internally coupled valve system. The problem arising from the dissimilar concentrations of the two analytes commonly occurring in serum is solved by applying the scale-expansion technique with a diode-array spectrophotometer. The determination ranges are 10–400 and 2–100 μg ml^?1 for lactic acid and glucose, respectively (r.s.d. 1.63 and 2.30%; n=11). Mixtures of these compounds in ratios up to 1:10 can be readily resolved, which allows their determination in serum with good results.     

Study on pre-irradiation grafting of BSANASI conjugates on agarose and its application

In this work we used N-acryloxysuccinimide (NASI) with a function group as the intermediate to graft the Bovine Serum Albumin (BSA), passthrough BSA / NASI conjugates, onto agarose which has been pre-irradiated in Co-60 γ-source.Preparation of BSA / NASI conjugates was carried out at 37°C for 2h, the molar ratio of BSA and NASI in reaction is 1:6. Pre-irradiation of agarose sample was carried out at room temperature in air and grafting was performed below 37°C for 5h under bubbling nitrogen. The total dose used was lower than 7 kGy.This technique is applicable to immobilize BSA and other proteins or separate the tryptophans enantiomer as well.     

New multiresidue analytical method dedicated to trace level measurement of brominated flame retardants in human biological matrices

A new method has been developed for the multi-residue measurement of the main brominated flame retardants (alpha- and gamma-hexabromocyclododecane (HBCD), tetrabromobisphenol A (TBBP-A) and polybrominated diphenyl ethers including decabromodiphenyl ether) in human biological matrices (serum, adipose tissue and breast milk). The proposed sample preparation procedure focused on reduced solvent and consumable consumption and associated procedural contamination, as well as reduced sample size. This protocol was fully validated and was proved to be suitable for identification of brominated flame retardant residues at ultra-trace level, as attested by preliminary results on real samples.     

Determination of serum aluminum by electrothermal atomic absorption spectrometry: A comparison between Zeeman and continuum background correction systems

Excessive exposure to aluminum (Al) can produce serious health consequences in people with impaired renal function, especially those undergoing hemodialysis. Al can accumulate in the brain and in bone, causing dialysis-related encephalopathy and renal osteodystrophy. Thus, dialysis patients are routinely monitored for Al overload, through measurement of their serum Al. Electrothermal atomic absorption spectrometry (ETAAS) is widely used for serum Al determination. Here, we assess the analytical performances of three ETAAS instruments, equipped with different background correction systems and heating arrangements, for the determination of serum Al. Specifically, we compare (1) a Perkin Elmer (PE) Model 3110 AAS, equipped with a longitudinally (end) heated graphite atomizer (HGA) and continuum-source (deuterium) background correction, with (2) a PE Model 4100ZL AAS equipped with a transversely heated graphite atomizer (THGA) and longitudinal Zeeman background correction, and (3) a PE Model Z5100 AAS equipped with a HGA and transverse Zeeman background correction. We were able to transfer the method for serum Al previously established for the Z5100 and 4100ZL instruments to the 3110, with only minor modifications. As with the Zeeman instruments, matrix-matched calibration was not required for the 3110 and, thus, aqueous calibration standards were used. However, the 309.3-nm line was chosen for analysis on the 3110 due to failure of the continuum background correction system at the 396.2-nm line. A small, seemingly insignificant overcorrection error was observed in the background channel on the 3110 instrument at the 309.3-nm line. On the 4100ZL, signal oscillation was observed in the atomization profile. The sensitivity, or characteristic mass (m₀), for Al at the 309.3-nm line on the 3110 AAS was found to be 12.1 ± 0.6 pg, compared to 16.1 ± 0.7 pg for the Z5100, and 23.3 ± 1.3 pg for the 4100ZL at the 396.2-nm line. However, the instrumental detection limits (3 SD) for Al were very similar: 3.0, 3.2, and 4.1 μg L^− 1 for the Z5100, 4100ZL, and 3110, respectively. Serum Al method detection limits (3 SD) were 9.8, 6.9, and 7.3 μg L^− 1, respectively. Accuracy was assessed using archived serum (and plasma) reference materials from various external quality assessment schemes (EQAS). Values found with all three instruments were within the acceptable EQAS ranges. The data indicate that relatively modest ETAAS instrumentation equipped with continuum background correction is adequate for routine serum Al monitoring.     

Determination of triglycerides in human serum by near-infrared diffuse reflectance spectroscopy using silver mirror as a substrate

Quantitative determination of serum triglycerides was achieved in diffuse reflectance mode using silver mirror as the substrate to enhance the spectral features.     

帕金森氏病与血清中微量元素关系的研究

以人血清为材料，探讨了帕金森氏病与微量元素的关系。采集了６２例患者血清和３３例健康人血清，用电感耦合高频等离子体发射光谱仪进行测定，结果发现，患者组血清锌明显低于对照组、铜、锰低于对照组，还发现患者组轻、中、重分型病人血清铅有明显差异，上述结果提示微量元素可能在帕金森氏病的发生、发展和转归中起着重要的作用。     

高血压患者血清中铁锌铜锰硒铬含量的研究

１６５例高血压患者血清中铁，锌，铜，锰，硒，铬的含量与对照组比较，结果显示：１．微量元素铁，锌含量明显升高，而血清铜，铬含量明显降低，其差异均有高度显著性，Ｐ〈０．０１；血清锰和硒的含量，两者差异无显著性，Ｐ〉０．０１．２．上述元素含量的特点可用高血压病的早期预报和治疗。