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991.
Hetter KM Bellis DJ Geraghty C Todd AC Parsons PJ 《Analytical and bioanalytical chemistry》2008,391(6):2011-2021
The production of modest quantities of candidate bone lead (Pb) reference materials is described, and an optimized production
procedure is presented. The reference materials were developed to enable an assessment of the interlaboratory agreement of
laboratories measuring Pb in bone; method validation; and for calibration of solid sampling techniques such as laser ablation
ICP-MS. Long bones obtained from Pb-dosed and undosed animals were selected to produce four different pools of a candidate
powdered bone reference material. The Pb concentrations of these pools reflect both environmental and occupational exposure
levels in humans. The animal bones were harvested post mortem, cleaned, defatted, and broken into pieces using the brittle
fracture technique at liquid nitrogen temperature. The bone pieces were then ground in a knife mill to produce fragments of
2-mm size. These were further ground in an ultra-centrifugal mill, resulting in finely powdered bone material that was homogenized
and then sampled-scooped into vials. Testing for contamination and homogeneity was performed via instrumental methods of analysis.
相似文献
Patrick J. ParsonsEmail: |
992.
Coleman AW Jebors S Shahgaldian P Ananchenko GS Ripmeester JA 《Chemical communications (Cambridge, England)》2008,(20):2291-2303
The para-acylcalix[n]arenes possess a very rich capacity to self-assemble into a wide variety of structures and sizes ranging from molecular assemblies through dimeric capsules, molecular sheets to nanoparticles. All these assemblies are capable of taking guest molecules and in the process of this inclusion discrete nanoscopic reaction vessels may be formed for photochemistry. Interestingly this uptake of quite large organic molecules occurs in the bulk in non-porous crystals without loss of crystallinity. At the air-water interface either as Langmuir monolayers or as colloidal suspensions the para-acylcalix[n]arenes show interaction with ionic species. The extension from para-acylcalix[4]arenes to para-acylcalix[8]arenes is in its infancy but already there is much promise for novel assemblies to be found. 相似文献
993.
de Greef TF Nieuwenhuizen MM Stals PJ Fitié CF Palmans AR Sijbesma RP Meijer EW 《Chemical communications (Cambridge, England)》2008,(36):4306-4308
Substitution of hydrogen bond directed supramolecular assemblies with ethylene glycol chains leads to a reduction in the association constant in apolar solvents, where the reduction of the association constant is dependent on the length of the aliphatic spacer connecting the hydrogen bonds and the ethylene glycol chain. 相似文献
994.
Barrès AL El-Ghayoury A Zorina LV Canadell E Auban-Senzier P Batail P 《Chemical communications (Cambridge, England)》2008,(19):2194-2196
Complementary shapes of the neutral symmetrical halogen-bond bis-donor core and octahedral inorganic cluster core prevent halogen-bonded polymers developing in more than one direction, favouring further templating by conducting radical cation slabs and yielding an 8 : 1 : 1 phase formulation instead of n : 2 : 1, with a 2D net, or m : 3 : 1, with a pseudo-cubic architecture, which may in principle also be targeted. 相似文献
995.
Kündig EP Enriquez Garcia A Lomberget T Perez Garcia P Romanens P 《Chemical communications (Cambridge, England)》2008,(30):3519-3521
Readily synthesised quincorine and quincoridine derived chiral diamines efficiently catalyse the asymmetric monobenzoylation of cyclic and acyclic meso-1,2-diols. 相似文献
996.
The standard oxidation states of central metal atoms in C
4v
nitrido ([M(N)(L)5]
z
) complexes are four units higher than those in corresponding nitrosyls ([M(NO)(L)5]
z
) (L=CN: z = 3−, M = Mn, Tc, Re; z = 2−, M = Fe, Ru, Os; L = NH3: z = 2+, M = Mn, Tc, Re; z = 3+, M = Fe, Ru, Os). Recent work has suggested that [Mn(NO)(CN)5]3− behaves electronically much closer to Mn(V)[b
2(xy)]2, the ground state of [Mn(N)(CN)5]3−, than to Mn(I)[b
2(xy)]2[e(xz,yz)]4. We have employed density functional theory and time-dependent density functional theory to calculate the properties of the
ground states and lowest-lying excitations of [M(N)(L)5]
z
and [M(NO)(L)5]
z
. Our results show that [M(N)(L)5]
z
and [M(NO)(L)5]
z
complexes with the same z value have strikingly similar electronic structures. 相似文献
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