Analysis of sexual assault evidence: statistical classification of condoms by ambient mass spectrometry

Desorption electrospray ionization mass spectrometry (DESI‐MS) and easy ambient sonic‐spray ionization mass spectrometry (EASI‐MS) are employed here in the forensic analysis of chemical compounds found in condoms and relative traces, and their analytical performances are compared. Statistical analysis of data obtained from mass spectra only was applied in order to obtain classification rules for distinguishing ten types of condoms. In particular, two supervised chemometric techniques [linear discriminant analysis (LDA) and soft independent modeling of class analogy (SIMCA)] were carried out on absolute and relative intensity values to test the performances of statistical models in terms of predictive capacity. The achieved classification of samples was excellent because of the high prediction percentages of the method used both for DESI and EASI mass spectrometry analyses, confirming these two as potential ambient ionization techniques for forensic analyses in case of sexual assault crimes. EASI‐MS showed 99% prediction ability for LDA using relative data and 100% prediction ability for SIMCA using both absolute and relative ones, while DESI showed 94% prediction ability for both LDA and SIMCA. The absence of any sample preparation technique gives advantages in terms of sample preservation and reduced contamination, allowing successive analyses to be performed on the same sample by other techniques. Copyright © 2015 John Wiley & Sons, Ltd.     

Nontargeted GC–MS approach for volatile profile of toasting in cherry,chestnut, false acacia,and ash wood

By using a nontargeted GC–MS approach, 153 individual volatile compounds were found in extracts from untoasted, light toasted and medium‐toasted cherry, chestnut, false acacia, as well as European and American ash wood, used in cooperage for aging wines, spirits and other beverages. In all wood types, the toasting provoked a progressive increase in carbohydrate derivatives, lactones and lignin constituents, along with a variety of other components, thus increasing the quantitative differences among species with the toasting intensity. The qualitative differences in the volatile profiles allow for identifying woods from cherry (being p‐anisylalcohol, p‐anisylaldehyde, p‐anisylacetone, methyl benzoate and benzyl salicylate detected only in this wood), chestnut (cis and trans whisky lactone) and false acacia (resorcinol, 3,4‐dimethoxyphenol, 2,4‐dihydroxy benzaldehyde, 2,4‐dihydroxyacetophenone, 2,4‐dihydroxypropiophenone and 2,4‐dihydroxy‐3‐methoxyacetophenone), but not those from ash, because of the fact that all compounds present in this wood are detected in at least one other. However, the quantitative differences can be clearly used to identify toasted ash wood, with tyrosol being most prominent, but 2‐furanmethanol, 3‐ and 4‐ethylcyclotene, α‐methylcrotonolactone, solerone, catechol, 3‐methylcatechol and 3‐hydroxybenzaldehyde as well. Regarding oak wood, its qualitative volatile profile could be enough to distinguish it from cherry and acacia woods, and the quantitative differences from chestnut (vanillyl ethyl ether, isoacetovanillone, butirovanillone, 1‐(5‐methyl‐2‐furyl)‐2‐propanone and 4‐hydroxy‐5,6‐dihydro‐(2H)‐pyran‐2‐one) and ash toasted woods. Copyright © 2014 John Wiley & Sons, Ltd.     

Polyphenolic profile as a useful tool to identify the wood used in wine aging

Although oak wood is the main material used in cooperage, other species are being considered as possible sources of wood for the production of wines and their derived products. In this work we have compared the phenolic composition of acacia (Robinia pseudoacacia), chestnut (Castanea sativa), cherry (Prunus avium) and ash (Fraxinus excelsior and F. americana) heartwoods, by using HPLC-DAD/ESI-MS/MS (some of these data have been showed in previous paper), as well as the changes that toasting intensity at cooperage produce in each polyphenolic profile. Before toasting, each wood shows a different and specific polyphenolic profile, with both qualitative and quantitative differences among them. Toasting notably changed these profiles, in general, proportionally to toasting intensity and led to a minor differentiation among species in toasted woods, although we also found phenolic markers in toasted woods. Thus, methyl syringate, benzoic acid, methyl vanillate, p-hydroxybenzoic acid, 3,4,5-trimethylphenol and p-coumaric acid, condensed tannins of the procyanidin type, and the flavonoids naringenin, aromadendrin, isosakuranetin and taxifolin will be a good tool to identify cherry wood. In acacia wood the chemical markers will be the aldehydes gallic and β-resorcylic and two not fully identified hydroxycinnamic compounds, condensed tannins of the prorobinetin type, and when using untoasted wood, dihydrorobinetin, and in toasted acacia wood, robinetin. In untoasted ash wood, the presence of secoiridoids, phenylethanoid glycosides, or di and oligolignols will be a good tool, especially oleuropein, ligstroside and olivil, together verbascoside and isoverbascoside in F. excelsior, and oleoside in F. americana. In toasted ash wood, tyrosol, syringaresinol, cyclolovil, verbascoside and olivil, could be used to identify the botanical origin. In addition, in ash wood, seasoned and toasted, neither hydrolysable nor condensed tannins were detected. Lastly, in chestnut wood, gallic and ellagic acids and hydrolysable tannins of both the gallotannin and ellagitannin type, can be used as chemical markers.     

Direct monitoring of drug degradation by easy ambient sonic-spray ionization mass spectrometry: the case of enalapril

Using enalapril maleate as a test case, the ability of ambient mass spectrometry, namely, via easy ambient sonic‐spray ionization mass spectrometry (EASI‐MS), to perform direct monitoring of drug degradation has been tested. Two manufacturing processes were investigated (direct compression and wet granulation), and the formation of degradation products was measured via both EASI‐MS and high‐performance liquid chromatography with ultraviolet detection for a total period of 18 months. Both techniques provide comparable results, which indicate that direct analysis by ambient mass spectrometric techniques presents a viable alternative for drug degradation monitoring with superior simplicity, throughput, and reliability (no sample manipulation), and comparable quantitative results. In terms of qualitative monitoring, the full mass spectra with intact species provided by EASI‐MS allow for comprehensive monitoring of known and unknown (or unexpected) degradation products. Copyright © 2011 John Wiley & Sons, Ltd.     

A dopant for improved sensitivity in easy ambient sonic‐spray ionization mass spectrometry

Recently, 3‐nitrobenzonitrile (3‐NBN) has been used to improve sensitivity of sonic‐spray ionization mass spectrometry. Easy ambient sonic‐spray ionization (EASI) is one of the simplest, gentlest and most used spray‐based desorption/ionization ambient techniques, but limited sensitivity has been commonly taken as its major drawback. Herein we investigate the use of 3‐NBN as a dopant in EASI‐MS for improved sensitivity. Using a few typical EASI samples as test cases, the presence of 10 ppm (µg ml^?1) of 3‐NBN in the spray solvent showed two to fourfold gains in EASI‐MS sensitivity as measured both by total ion current and S/N ratios, accompanied with significant reductions in chemical noise. Sensitivity for DESI using 3‐NBN as a dopant also improved and dopant DESI versus dopant EASI sensitivities were compared. The use of solvent dopants seems therefore to be a promising strategy to improve sensitivity for spray‐based ambient MS techniques. Copyright © 2015 John Wiley & Sons, Ltd.     

A capillary electrophoresis system with dual capacitively coupled contactless conductivity detection and electrospray ionization tandem mass spectrometry

A commercial system that is comprised of a CE coupled to an ESI triple quadrupole mass spectrometer was equipped with two capacitively coupled contactless conductivity detectors (C⁴Ds). The first C⁴D was positioned inside the original cartridge, and the second C⁴D was positioned as close as possible to the ESI probe entrance by using a 3D‐printed support. The C⁴Ds electropherograms were matched to the ESI‐MS electropherogram by correcting their timescales by the factor L_T/L_D, where L_T and L_D are the total capillary length and the length until the C⁴D, respectively. A general approach for method development supporting the simultaneous conductivity and MS detection is discussed, while application examples are introduced. These examples include the use of C⁴D as a simple device that dismiss the use of an EOF marker, a low‐selectivity detector that continuously provide information about unexpected features of the sample, and even a detector that can be more sensitive than ESI‐MS. The C⁴D used in this setup proved to have a smaller contribution to the peak broadening than ESI‐MS, which allowed that a C⁴D, positioned at 12 cm from the inlet of an 80‐cm‐long capillary, could be used to foresee position and shape of the peaks being formed 6.8 times slower at the ESI‐MS electropherogram.     

Sulfides: chemical ionization induced fragmentation studied with Proton Transfer Reaction‐Mass Spectrometry and density functional calculations

We report the energy‐dependent fragmentation patterns upon protonation of eight sulfides (organosulfur compounds) in Proton Transfer Reaction‐Mass Spectrometry (PTR‐MS). Studies were carried out, both, experimentally with PTR‐MS, and with theoretical quantum‐chemical methods. Charge retention usually occurred at the sulfur‐containing fragment for short chain sulfides. An exception to this is found in the unsaturated monosulfide allylmethyl sulfide (AMS), which preferentially fragmented to a carbo‐cation at m/z 41, C₃H₅⁺. Quantum chemical calculations (DFT with the M062X functional 6‐31G(d,p) basis sets) for the fragmentation reaction pathways of AMS indicated that the most stable protonated AMS cation at m/z 89 is a protonated (cyclic) thiirane, and that the fragmentation reaction pathways of AMS in the drift tube are kinetically controlled. The protonated parent ion MH⁺ is the predominant product in PTR‐MS, except for diethyl disulfide at high collisional energies. The saturated monosulfides R‐S‐R’ (with R<R’) have little or no fragmentation, at the same time the most abundant fragment ion is the smaller R‐S⁺ fragment. The saturated disulfides R‐S‐S‐R display more fragmentation than the saturated monosulfides, the most common fragments are disulfide containing fragments or long‐chain carbo‐cations. The results rationalize fragmentation data for saturated monosulfides and disulfides and represent a detailed analysis of the fragmentation of an unsaturated sulfide. Apart from the theoretical interest, the results are in support of the quantitative analysis of sulfides with PTR‐MS, all the more so as PTR‐MS is one of a few techniques that allow for ultra‐low quantitative analysis of sulfides. Copyright © 2013 John Wiley & Sons, Ltd.     

Reactivity of 4‐thiothymidine with Fenton reagent investigated by UV‐visible spectroscopy and electrospray ionization mass spectrometry

The reactivity of the sulfur‐containing nucleoside 4‐thio‐(2′‐deoxy)‐thymidine usually abbreviated as 4‐thio‐thymidine, (S⁴‐TdR) under Fenton conditions, ie, in the presence of H₂O₂ and catalytic amounts of Fe(II), was investigated by UV‐vis spectroscopy and electrospray ionization single and tandem mass spectrometry (ESI‐MS and MS/MS). S⁴‐TdR hydroxylated on the S atom was found to be a key reaction intermediate, ultimately leading to (2′‐deoxy)‐thymidine usually abbreviated as thymidine, (TdR) as the main reaction product. This finding was in accordance with the outcome of the reaction between S⁴‐TdR and H₂O₂, previously investigated in our laboratory. On the other hand, the additional presence of ?OH radicals, induced by the Fe(II)/H₂O₂ combination, led to the increased generation of another interesting S⁴‐TdR product, already observed after its reaction with H₂O₂ alone, ie, the covalent dimer including a S? S bridge between two S⁴‐TdR molecules. More importantly, multihydroxylated derivatives of S⁴‐TdR and TdR were detected as peculiar products obtained under Fenton conditions. Among them, a product bearing an OH group both on the methyl group linked to the thymine ring and on the C5 atom of the ring was found to prevail. The results obtained during this study, integrated by those found previously in our laboratory, indicate 4‐thiothymidine as a promising molecular probe for the recognition, through a careful characterization of its reaction products, of the prevailing species among reactive oxygen species (ROS) corresponding to singlet‐state oxygen, hydrogen peroxide, and hydroxylic radical.     

LC‐DAD/ESI‐MS/MS study of phenolic compounds in ash (Fraxinus excelsior L. and F. americana L.) heartwood. Effect of toasting intensity at cooperage

The phenolic composition of heartwood extracts from Fraxinus excelsior L. and F. americana L., both before and after toasting in cooperage, was studied using LC‐DAD/ESI‐MS/MS. Low‐molecular weight (LMW) phenolic compounds, secoiridoids, phenylethanoid glycosides, dilignols and oligolignols compounds were detected, and 48 were identified, or tentatively characterized, on the basis of their retention time, UV/Vis and MS spectra, and MS fragmentation patterns. Some LMW phenolic compounds like protocatechuic acid and aldehyde, hydroxytyrosol and tyrosol, were unlike to those for oak wood, while ellagic and gallic acid were not found. The toasting of wood resulted in a progressive increase in lignin degradation products with regard to toasting intensity. The levels of some of these compounds in medium‐toasted ash woods were much higher than those normally detected in toasted oak, highlighting vanillin levels, thus a more pronounced vanilla character can be expected when using toasted ash wood in the aging wines. Moreover, in seasoned wood, we found a great variety of phenolic compounds which had not been found in oak wood, especially oleuropein, ligstroside and olivil, along with verbascoside and isoverbascoside in F. excelsior, and oleoside in F. americana. Toasting mainly provoked their degradation, thus in medium‐toasted wood, only four of them were detected. This resulted in a minor differentiation between toasted ash and oak woods. The absence of tannins in ash wood, which are very important in oak wood, is another peculiar characteristic that should be taken into account when considering its use in cooperage. Copyright © 2012 John Wiley & Sons, Ltd.     

Chemical profiling and separation of bioactive secondary metabolites in Maca (Lepidium peruvianum) by normal and reverse phase thin layer chromatography coupled to desorption electrospray ionization‐mass spectrometry

Maca is a Peruvian tuberous root of the Brassicaceae family grown in the central Andes between altitudes of 4000 and 4500 m. The medicinal plant is a nutraceutical with important biological activities and health effects. In this study, we report a rapid high‐performance thin layer chromatography (HPTLC)‐(?)desorption electrospray ionization (DESI)‐mass spectrometry (MS) method to profile and separate intact glucosinolates without prior biochemical modifications from the hydromethanolic extracts of two phenotypes, red and black Maca (Lepidium peruvianum) seeds. In the first stage of the plant's life cycle, aromatic glucosinolates were the main chemical constituents whereby six aromatic, three indole, and one aliphatic glucosinolate were tentatively identified. At the seedling stage, glucolepigramin/Glucosinalbin was the most predominant precursor, rather than Glucotropaeolin, which is mainly found in hypocotyls and roots. These findings lead us to suggest that glucolepigramin/glucosinalbin play a major role as active precursors in the biosynthetic pathways of other secondary metabolites in the early stages of plant development. Between red and black Maca seeds, only minor differences in the relative abundances of glucosinolates were observed rather than different plant metabolites. For the first time, we report six potential plant antibiotics, phytoanticipins: glycosylated ascorbigens and dihydroascorbigens from Maca seeds. We also investigated a targeted reverse phase C₁₈ functionalized TLC‐DESI‐MS method with high sensitivity and specificity for Brassicaceae fatty acids in Maca seeds and health supplements such as black Maca root lyophilized powder and tinctures. The investigation of secondary metabolites by normal and reverse phase TLC‐DESI‐MS methods, described in this study, can aid in their identification as they begin to emerge in later stages of development in plant tissues such as leaves, hypocotyls, and roots.     

Triple Helicates with Golden Strands: Self‐Assembly of M2Au6 Complexes from Gold(I) Metallaligands and Iron(II), Cobalt(II) or Zinc(II) Cations

Alkynyl gold(I) metallaligands [(AuC≡Cbpyl)₂(μ‐diphosphine)] (bpyl=2,2′‐bipyridin‐5‐yl; diphosphine=Ph₂P(CH₂)_nPPh₂, [n=3 (L^Pr), 4 (L^Bu), 5 (L^Pent), 6 (L^Hex)], dppf (L^Fc), Binap (L^Binap) and Diop (L^Diop)) react with MX₂ (M=Fe, Zn, X=ClO₄; M=Co, X=BF₄) to give triple helicates [M₂(L^R)₃]X₄. These complexes, except those containing the semirigid L^Binap metallaligand, present similar hydrodynamic radii (determined by diffusion NMR spectroscopy measurements) and a similar pattern in the aromatic region of their ¹H NMR spectra, which suggests that in solution they adopt a compact structure where the long and flexible organometallic strands are folded. The diastereoselectivity of the self‐assembly process was studied by using chiral metallaligands, and the absolute configuration of the iron(II) complexes with L^Binap and L^Diop was determined by circular dichroism spectroscopy (CD). Thus, (R)‐L^Binap or (S)‐L^Binap specifically induce the formation of (Δ,Δ)‐[Fe₂((R)‐L^Binap)₃](ClO₄)₄ or (Λ,Λ)‐[Fe₂((S)‐L^Binap)₃](ClO₄)₄, respectively, whereas (R,R)‐ or (S,S)‐L^Diop give mixtures of the ΔΔ‐ and ΛΛ‐diastereomers. The ΔΔ helicate diastereomer is dominant in the reaction of Fe^II with (R,R)‐L^Diop, whereas the ΛΛ isomer predominates in the analogous reaction with (S,S)‐L^Diop. The photophysical properties of the new dinuclear alkynyl complexes and the helicates have been studied. The new metallaligands and the [Zn₂(L^R)₃]⁴⁺ helicates present luminescence from [π→π*] excited states mainly located in the C≡Cbpyl units.     

Construction of Hierarchical Nanotubes Assembled from Ultrathin V3S4@C Nanosheets towards Alkali‐Ion Batteries with Ion‐Dependent Electrochemical Mechanisms

Ultrathin core–shell V₃S₄@C nanosheets assembled into hierarchical nanotubes (V₃S₄@C NS‐HNTs) are synthesized by a self‐template strategy and evaluated as general anodes for alkali‐ion batteries. Structural/physicochemical characterizations and DFT calculations bring insights into the intrinsic relationship between crystal structures and electrochemical mechanisms of the V₃S₄@C NS‐HNTs electrode. The V₃S₄@C NS‐HNTs are endowed with strong structural rigidness owing to the layered VS₂ subunits and interlayer occupied V atoms, and efficient alkali‐ion adsorption/diffusion thanks to the electroactive V₃S₄‐C interfaces. The resulting V₃S₄@C NS‐HNTs anode exhibit distinct alkali‐ion‐dependent charge storage mechanisms and exceptional long‐durability cyclic performance in storage of K⁺, benefiting from synergistic contributions of pseudocapacitive and reversible intercalation/de‐intercalation behaviors superior to those of the conversion‐reaction‐based Li⁺‐/Na⁺‐storage counterparts.     

Structure of Pyridazine in the S1 State: Experiment and Theory

The molecular structure of pyridazine in the first electronically excited state (S₁) is deduced from the combined use of resonance‐enhanced two‐photon ionization and mass‐analyzed threshold ionization spectroscopic methods. The equation‐of‐motion coupled‐cluster single and double (EOM–CCSD) calculation gives the distorted planar geometry for the most stable structure of the S₁ pyridazine. The symmetry constraint of C_2v is relaxed to that of C_s, and consequently many in‐plane vibrational modes are found to be optically active in both S₁–S₀ and D₀–S₁ excitation spectra, being appropriately assigned from the comparison of their frequencies with ab initio values. This indicates that the S₁–S₀ excitation is partially localized, and provides an alternative explanation for the long‐standing spectroscopic puzzle in S₁ pyridazine.     

Volumetric Properties for the Electrolyte (NaCl,NaBr and NaI) Monosaccharide (D‐Mannose and D‐Ribose)‐Water Systems at 298.15 K

Densities have been measured for the electrolyte (NaCl, NaBr and NaI)‐monosaccharide (D ‐mannose and D‐ribose)‐water solutions at 298.15 K. These data have been used to calculate the apparent molar volumes of the saccharides (V_Φ,S) and electrolytes (V_Φ,E) in the studied solutions. Infinite dilution apparent molar volumes, V_Φ,S⁰ and V_Φ,E⁰, have been evaluated, together with the standard transfer volumes of the saccharides (Δ_tV_S⁰) from water to aqueous electrolyte solutions and those of the electrolytes (Δ_tV_E⁰) from water to aqueous saccharide solutions. It was shown that both the Δ_tV_S⁰ and Δ_tV_E⁰ values are positive and increase with increasing molalities of sodium halides and saccharides, respectively. Overall, the Δ_tV_S⁰ and Δ_tV_E⁰ values have the order of NaCl > NaBr > NaI except for NaI‐ribose and NaI‐ribose. Volumetric interaction parameters for the electrolyte‐monosaccharide pairs in water were obtained and interpreted by the stereochemistry of the monosaccharide molecules and the structural interaction model.     

Specificity enhancement by electrospray ionization multistage mass spectrometry – a valuable tool for differentiation and identification of ‘V’‐type chemical warfare agents

The use of chemical warfare agents has become an issue of emerging concern. One of the challenges in analytical monitoring of the extremely toxic ‘V’‐type chemical weapons [O‐alkyl S‐(2‐dialkylamino)ethyl alkylphosphonothiolates] is to distinguish and identify compounds of similar structure. MS analysis of these compounds reveals mostly fragment/product ions representing the amine‐containing residue. Hence, isomers or derivatives with the same amine residue exhibit similar mass spectral patterns in both classical EI/MS and electrospray ionization‐MS, leading to unavoidable ambiguity in the identification of the phosphonate moiety. A set of five ‘V’‐type agents, including O‐ethyl S‐(2‐diisopropylamino)ethyl methylphosphonothiolate (VX), O‐isobutyl S‐(2‐diethylamino)ethyl methylphosphonothiolate (RVX) and O‐ethyl S‐(2‐diethylamino)ethyl methylphosphonothiolate (VM) were studied by liquid chromatography/electrospray ionization/MS, utilizing a QTRAP mass detector. MS/MS enhanced product ion scans and multistage MS³ experiments were carried out. Based on the results, possible fragmentation pathways were proposed, and a method for the differentiation and identification of structural isomers and derivatives of ‘V’‐type chemical warfare agents was obtained. MS/MS enhanced product ion scans at various collision energies provided information‐rich spectra, although many of the product ions obtained were at low abundance. Employing MS³ experiments enhanced the selectivity for those low abundance product ions and provided spectra indicative of the different phosphonate groups. Study of the fragmentation pathways, revealing some less expected structures, was carried out and allowed the formulation of mechanistic rules and the determination of sets of ions typical of specific groups, for example, methylphosphonothiolates versus ethylphosphonothiolates. The new group‐specific ions elucidated in this work are also useful for screening unknown ‘V’‐type agents and related compounds, utilizing precursor ion scan experiments. Copyright © 2013 John Wiley & Sons, Ltd.     

Determination of eight nitrosamines in water at the ng L levels by liquid chromatography coupled to atmospheric pressure chemical ionization tandem mass spectrometry

In this work, we have developed a sensitive method for detection and quantification of eight N-nitrosamines, N-nitrosodimethylamine (NDMA), N-nitrosomorpholine (NMor), N-nitrosomethylethylamine (NMEA), N-nitrosopirrolidine (NPyr), N-nitrosodiethylamine (NDEA), N-nitrosopiperidine (NPip), N-nitroso-n-dipropylamine (NDPA) and N-nitrosodi-n-butylamine (NDBA) in drinking water. The method is based on liquid chromatography coupled to tandem mass spectrometry, using atmospheric pressure chemical ionization (APCI) in positive mode with a triple quadrupole analyzer (QqQ). The simultaneous acquisition of two MS/MS transitions in selected reaction monitoring mode (SRM) for each compound, together with the evaluation of their relative intensity, allowed the simultaneous quantification and reliable identification in water at ppt levels. Empirical formula of the product ions selected was confirmed by UHPLC-(Q)TOF MS accurate mass measurements from reference standards.Prior to LC–MS/MS QqQ analysis, a preconcentration step by off-line SPE using coconut charcoal EPA 521 cartridges (by passing 500 mL of water sample) was necessary to improve the sensitivity and to meet regulation requirements. For accurate quantification, two isotope labelled nitrosamines (NDMA-d₆ and NDPA-d₁₄) were added as surrogate internal standards to the samples.The optimized method was validated at two concentration levels (10 and 100 ng L⁻¹) in drinking water samples, obtaining satisfactory recoveries (between 90 and 120%) and precision (RSD < 20%). Limits of detection were found to be in the range of 1–8 ng L⁻¹. The described methodology has been applied to different types of water samples: chlorinated from drinking water and wastewater treatment plants (DWTP and WWTP, respectively), wastewaters subjected to ozonation and tap waters.     

Molecular Structure, Vibrational Spectrum and Ionization Energy of m-Dimethoxybenzene

The optimized molecular geometries of the three rotamers of m-dimethoxybenzene in the ground So and electronically excited Sl states were predicted by ab initio and density functional theory （DFF） calculations. Their vibrational spectra in the St state were studied by one color resonant two photon ionization （1C-R2PI） method, and their ionization energies were measured by two color resonant two photon ionization （2C-R2PI） experiment. The optimized molecular geometries showed that the total energy of conformer a was the lowest in the So state. Most of the active vibrations assigned from the 1C-R2PI spectrum were found to be of the in-plane ring modes. The ionization energies （IE） of conformers a, b and c were determined to be 63521, 64487 and 63755 cm^-1, respectively.     

Synthesis and Crystal Structures of Dinuclear Palladium and Mononuclear Nickel Complexes of Macrocyclic N8S4 Ligands

The N₈S₄ donor ligand L¹ has been investigated regarding its capability to support the formation of coordinatively unsaturated Pd₂ complexes and its use as a starting material for functionalized N₈S₄ systems. L¹ represents a macrotricyclic ligand comprising four 4‐tert‐butyl‐2,6‐bis(aminomethyl)thiophenolate units, whose N and S atoms are linked by ethylene units. Treatment of L₁ with [Pd(NCMe)₂Cl₂] produced the dinuclear complex [Pd₂Cl₂(H₂L¹)]⁴⁺, which was isolated as its pale‐yellow perchlorate salt [Pd₂Cl₂(H₂L¹)](ClO₄)₄ (H₂ 1 ) and characterized by elemental analysis, IR, NMR and MS spectroscopy and X‐ray crystallography. The structure shows two planar PdN₂SCl units which are located in the central 24‐membered ring of L¹. Reaction of L¹ with CH₂O/HCO₂H under Eschweiler‐Clarke conditions followed by deprotection with sodium in liquid ammonia furnished the permethylated octaamine‐tetrathiophenol H₄L⁴. The identity of H₄L⁴ was ascertained by an X‐ray crystal structure determination of one of its metal complexes.     

Fabric softeners: nearly instantaneous characterization and quality control of cationic surfactants by easy ambient sonic‐spray ionization mass spectrometry

A tiny droplet of typical samples of fabric softeners from different commercial brands placed on a smooth paper surface was subjected to easy ambient sonic‐spray ionization mass spectrometry (EASI‐MS). With no need for sample‐preparation or pre‐separation procedures, EASI‐MS and EASI‐MS/MS identify nearly instantaneously the main surfactants and the homologous series employed in their formulations. Adulterated and low quality samples containing no or less efficient softeners are also easily recognized. Copyright © 2009 John Wiley & Sons, Ltd.     

Volumetric Properties and Volumetric Interaction Parameters of the CsCl‐saccharides (D‐glucose,D‐fructose)‐water Solutions at 298.15 K

Densities have been measured for the CsCl‐saccharide (D‐glucose, D‐fructose)‐water systems at 298.15 K. These data were used to calculate the apparent molar volume of CsCl (V_φ,E) and the saccharides (V_φ,S), and the infinite dilution apparent molar volume V_φ,E⁰ and V_φ,S⁰ in the studied solutions. In addition, the standard transfer volume Δ_tV_φ,E⁰ of CsCl from water to aqueous saccharides solutions, and Δ_tV_φ,S⁰ of saccharides from water to CsCl solutions have been evaluated and discussed using the structural interaction model. The volumetric interaction parameters for CsCl with saccharide in water were obtained and analyzed by the group additivity principle and the stereochemistry of the saccharide molecules.