Analytical Chemistry,Past, Present and Future*This paper is dedicated to the Editorial Board of Analytical Letters.

ABSTRACT

Analytical Chemistry as a science has its own history as well as an important present and a sure future.

The aim of this paper is to demonstrate the role of Analytical Chemistry as a science and of Chemical Analysis as an art in the development of human society.

The correlation between method and instrument hyphenated by the sample is discussed along a long period of active Analytical Chemistry.

The connection between theory of Analytical Chemistry and the practice of chemical analysis enables us to be sure of the future of Analytical Chemistry.

We must consider that to do science it is necessary to know the history of science as well as to make research to be used not only in the present, but also in the near future.

Surely, Analytical Chemistry as a real scientific area will be on the top of sciences in the next century.     

A Kinetic and Quantitative Approach to Peak Splitting Phenomena When Using 2-Propanol as Modifier in Adsorption HPLC

Abstract

When using 2-propanol as a modifier in adsorption chromatography, a “satellite” peak is observed if a shight excess of a polar chlorinated hydrocarbon, such as CH₂Cl₂, is injected.

This satellite peak whose appearance is related to the presence of 2-propanol, has been identified as a part of the CH₂Cl₂ injected. The satellite peak behaves chromatographically mainly as a normal solute peak and its area is proportional to both the amount of CH₂Cl₂ injected and the concentration of 2-propanol in the mobile phase and on the other hand inversely related to the flow-rate and the concentration of CH₂Cl₂ in the mobile phase.

A physico-chemical model is proposed based on the perturbance of the dynamic equilibrium when the sample enters the column. The model is compatible with the experimental results and explains the origin of the satellite peak as well as its chromatographic behaviour. It also allows a better understanding of the role of a modifier related to its adsorption-desorption process.     

Ethanol,the ultimate feedstock

Ethanol appears to be a key factor in the “biomass alternative” to fossil feedstocks for producing fuels and chemicals. If produced at a low enough price relative to crude oil, it and its derivates could account for 159 billion pounds, or 50%, of the US production of synthetic organic chemicals, presently valued at $113 billion. This use would consume 4.2 billion bushels, or about 54%, of the corn crop.

This study evaluated the potential savings in ethanol manufacture to be gained by applying advanced process engineering or genetic engineering of improved organisms, centering on the use of fluidized bed bioreactors operating at high cell densities with immobilized cells of either the Saccharomyces yeast or the bacterium: Zymomonas mobilis.

A new continuous plant could produce at about $1.82/gal based on Zymomonas or $1.97/gal based on the Saccharomyces yeast. The bacterium has a competitive edge as a result of its lower sensitivity to product inhibition.

There appears to be no inherent design limitation to effect the engineering improvements required for the advanced process. In a longer-term, more difficult research effort, it might be possible to reduce or eliminate product inhibition to reduce cost even further.

     

Synthesis of bicyclo[2.2.1]heptyl monoethers of aliphatic diols

An effective procedure for the synthesis of bicyclic monoethers by etherification of bicyclo[2.2.1] heptane-exo-2-ol and its exo-5-methyl-substituted derivative by aliphatic diols in the presence of naphthalene-1,5-disulfonic acid as a catatlyst was developed.

     

Simple Device for Isolation of Organic Compounds from Water

Abstract

A simple device for isolation of organic compounds from aqueous samples has been designed and its operating parameters tested during bioth periodic and continuous operation using isolation of organochlorine compounds as an example.

A stream of an aqueous sample is pumped at elevated temperature by a piston pump to an unit for expransion of the liquid phase surface, where the liquid is sprayed on the walls of the unit and flows down freely.

Organochlorine compounds passing to the gaseous phase are purged with a stream of purified air, oxidied and the chlorides formed are determined coulometrically. The designed device, due to its simplicity, can be built and employed in each averagely equipped laboratory.     

Simultaneous LC–UV Determination of 5-Methyl-1-(3-fluorophenyl)-2-(1H)- pyridone and Its Two Metabolites in Rat Plasma

A simple, rapid, and reproducible isocratic reverse-phase HPLC method was developed to simultaneously determine AKF-PD and its two oxidized metabolites in rat plasma. 5-Carboxyl-1-phenyl-2-(1H)-pyridone and phenacetin were used as internal standards to ensure the precision and accuracy of the method. The analytes were separated on a C₁₈ reversed-phase column with methanol—phosphate buffer (20 mM, pH 2.5) as mobile phase. The limits of detection for AKF-PD and its two oxidized metabolites was 0.1 μg mL⁻¹. The method is applicable for the pharmacokinetic studies of AKF-PD and its metabolites in rats.

     

Massenspektrometrische Strukturermittlung von 21-Oxogelsemin

The structure of a further minor alkaloid of Gelsemium sempervirens (L.) Ait., could be elucidated on the basis of mass-spectrometrical and chemical evidence as 21-oxogelsemin (3). The mass spectra of3 and of its hydrogenation product (4) are discussed.

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Mit 3 Abbildungen

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Herrn Prof. Dr.O. Hoffmann-Ostenhof zum 60. Geburtstag gewidmet.

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2. Mitt.:M. Wichtl, A. Nikiforov, G. Schulz, Susanne Sponer undK. Jentzsch, Mh. Chem.104, 99 (1973).     

L-Ascorbic Acid Determination in Fruits and Medical Formulations by Ion Interaction Reagent Reverse Phase HPLC Technique

Abstract

The content of L-ascorbic acid has been evaluated in juices of fruits and in typical medical formulations. Grapefruits, orange, lemon and kiwi, as well as tablets of vitamin C and antipyretic medicine added with vitamin C have been analyzed.

The ion interaction reagent reverse phase HPLC chromatographic technique has been employed, making use of octylaminium salicylate as interaction reagent and of a C-18 spherical 5 μ m column as stationary phase.

Sensitivity levels of the order of 100 pmoles can be obtained. The dependence on time and temperature of the oxidation processes which L-ascorbic acid undergoes during its preservation has also been studied.     

Die empirische Matrixkorrektur intermediärer Proben in der Röntgenspektrometrie

Very thin samples show proportionality between the intensity and the weight per unit area of the analyte. Matrix effects do not exist. The matrix effects of very thick samples suitably can be corrected by multiple regression according to Eq. (1). Between these two kinds of samples the intermediate ones are situated with the intensity of the analyte as a function of the weight per unit area of the sample as an additional parameter of correction.

It was shown that these samples can also be corrected by multiple regression without knowing the weight per unit area of the samples by using the weight per unit area of the analyte instead of its concentration according to Eq. (5). This was demonstrated by calculation with simulated standards.

In addition to the described effects the correction program Eq. (5) is able to correct for the influences of dust particle sizes and their depth distribution in the filter.

     

Liebig's Metamorphosis: From Organic Chemistry to the Chemistry of Agriculture

Abstract

In Oxford Street a collegemet the eyes

of those who breathe the smoke of London skies,

Grand was its structure, noble was the place

Framed for the training of the rising race.     

Isotopic Composition as an Indicator of Origin of Lead Accumulations in Surface Soils

Abstract

Surface accumulation of lead in urban soils is a well-known phenomenon but its marked accumulation in remote, upland areas is less well documented. Such enrichments (up to 500 mg/kg) could be a potential hazard to grazing sheep.

Lead isotope ratios determined by thermal ionization mass spectrometry are reported for three soil profiles from remote, upland areas with highly enriched surface concentrations of lead. Isotope ratios in recent rainwater samples from six widely dispersed sites in Scotland are also discussed.

Lead in current rainwater samples has very low isotope ratios indicating its likely origin from petrol-derived sources. The ratios in soil surface horizons are not as low as those in current rainwater samples which suggests that lead accumulated over many decades is derived from both petrol-derived sources and also from other industrial emissions such as smelting and steel production.     

A New High Performance Chromatographic Method for Polyamine Analysis in Picea Needles,Without Previous Extract Purification

Abstract

A fully automated, fast and sensitive method for the separation of 19 interrelated amino compounds is presented.

With the help of a high performance amino-acid analyser, ion-exchange chromatography was used to separate ornithine, lysine and arginine from its decarboxylated products: putrescine, cadaverine and agmatine. Also included are ammonia, ethanolamine, histamine, aminopropane, diaminopropane, acetyl and carbamyl putrescine as well as most of the known polyamines, i.e.: nor-spermidine, spermidine, homospermidine, thermine, spermine and 1,7-diaminoheptane which serves as internal standard for the quantification. The method uses 2 buffers, 1 single temperature and fluorimetric detection. It takes 72 minutes and is of picomole sensitive level. This method is well suited for the analysis of crude samples without preliminary purification, thus saving time and reducing preparative losses.

The reproducibility of the method and its application for the analyses of samples from different biological sources, such as microorganisms, plant and animal material has been tested in our laboratory for more than one year with excellent results. This method could serve as a powerful tool for the analysis of these amino compounds in which there is currently considerable interest.

Preliminary results concerning compared studies of healthy and injured needles of air polluted Picea are discussed.     

A Study on the Preparation,Structure, and Properties of Microcrystalline Cellulose

Abstract

The preparation, structure, and properties of microcrystalline cellulose (MCC) from rice straw were investigated by IR, x-ray, viscometry, polarizing microscope, SEM, etc. The results are as follows:

1. The leveling-off degree of polymerization (LODP) obtained from rice straw is about 80–150. The dimensions of MCC granules are 20–30 μm length, 0.5–0.8 μm thick, and the crystallinity is about 80%.

2. The aqueous suspension of a certain concentration of MCC can form a gel under the effect of shear force. The viscosity of MCC gel increased with an increasing content of MCC in water. A sharper increase of viscosity occurred in the 3–6% range.

3. The addition of one or two valence salts into the MCC gel increased the viscosity.

4. The viscosity of MCC gel has its maximum value at pH 8.

5. The MCC gel as an emulsifying agent can form a stable emulsion in the oil/water system when the ratio of oil/water is below 6/4.     

Spectrofluorimetric Evidence of the Transport of Marine Organic Matter in Antarctic Snow Via Air-Sea Interaction

Abstract

This paper considers the importance of marine aerosol in the atmosphere. As a consequence of its peculiar generation mechanism, it is also considered as a possible contributor to the transport of man-made microcomponents via air-sea interaction, especially in remote sites.

In view of future marine aerosol studies, the dominant presence of marine aerosol components in coastal Antarctic snow is discussed the presence of fluorescent marine organic matter in Antarctic snow is shown. Its “marum” nature is evidenced.

We give a tentative interpretation of the experimental data, and make a hypothesis concerning the variations in marine aerosol composition in correspondence to various altitudes.     

Spectrophotometric Determination of Palladium with Sodium Ethylene-Bis-Selendglycollate

Abstract

SUMMARY

Palladium was determined spectrophotometrically with sodium ethylene-bis-selenoglycollate in acid medium. The system obeys Beer' law in the range 0.25–0, 3 5 μg.ml^?1 and the molar absorptivity is 2.4 × 10⁴ 1. mol^?1 .cm^?1. Determination of palladium in the presence of many ions is reported.

In spite of the fact that selenium compounds have rarely been used as organic analytical reagents and one finds many palladium determination methods in the literature, this paper fits into the general Purpose reported before ^1,2 :systematic comparison of organic sulphur, sellenium and tellurium compounds as analytical reagents in agreement with propositions made some years agp ^3,4

In previous work⁵ the behaviour of the ethylseleno glycollic (L₁), selenodiglycollic (L₂) and ethylene-bis-selenoglycollic (L₃) anions in acidic solutions of some “soft”, “borderline” and “hard” cations was studied.

The results obtained for Pd(II) afforded evidences that its determination could be run with the three mentioned ligands.

Nevertheless, L₃ was selected because it provides the most sensitive signal and its synthesis is very simple and its overall yield is excellent⁶

From the qualitative study⁵ the foreseen selectivity could present some restrictions, but there is little doubt about the usefulness of the method that will be proposed, in various schemes of determination. Similar comments Beamish have been made about EDTA method for Pd(II) determination⁸     

Preparation and preliminary bioevaluation of 68Ga-oxine in lipiodol as a potential liver imaging agent

Lipiodol functions as an embolizing agent for trans-arterial embolization and is used to deliver localized doses of chemotherapeutic drugs as well as ionizing radiation to cancerous tissue of the liver. Therefore, an attempt was made to prepare ⁶⁸Ga-labeled lipiodol, which may have potential as a PET radiotracer for imaging of liver cancer. ⁶⁸Ga-labeled lipiodol was prepared by a two-step procedure involving formation of highly lipophilic ⁶⁸Ga-oxine complex followed by its dispersion in lipiodol. Preliminary biological evaluation in normal Wistar rats revealed satisfactory hepatic retention with insignificant uptake in any other major organ/tissue indicating promising potential of the agent.

     

Monitoring Of Nitrifying Processes In Ground Water By Ion Chromatography

Abstract

The removal of ammonia from mineral medium containing known concentrations of ammonia (up to 300 mg/L) and from ground water by biological oxidation was studied. Nitrifying bacteria were isolated from ground water containing ammonia.

Ammonium ion was determined by a standard titration technique while nitrite and nitrate ions were determined by ion chromatography (IC Supersep anion column) using 1.5 mM phtalic acid solution containing 5 % acetonitril as eluent.

Depending on its concentration in water biooxidation of ammonia lasted from 48 hours till three weeks.     

GC-MS Analysis of Contaminants in Breathing Oxygen

Abstract

Oxygen used for flight crews and for extra-hospital therapies is kept in vacuum containers and maintained as liquid phase (LOX) until use; by using this procedure, the weight of the breathing apparatus is reduced, thus extending breathing oxygen availability and improving safety by using atmosphere pressure sampler.

On the other hand, because of its low boiling point (?183°C), during storage and distribution, LOX shows continuous evaporation with a constant increase in pollutant concentration obtained in the LOX production.

Therefore, LOX is subjected to a strict quality control to evaluate the contamination levels from production until its use.

In this study, an analytical procedure has been optimised to measure the main LOX contaminants (freon, chlorinated solvents, light hydrocarbons, CO₂, CO, and N₂O) based on a single technique (GC-MS) and two chromatographic columns (Poraplot Q/HT and HP-Plot molecular sieve 5 A). The proposed method is an improvement in terms of time as well cost of analysis and selectivity with respect to the present methods based on three chromatographic techniques (GC-ECD, GC-FID, GC-HID) and four different columns.     

Synthesis and properties of non-symmetrical phosphor(ɪɪɪ)arene macrocycle based on 4,4′-iminodiphenol, 4,4′-methylenediphenol,and phenylphosphonic acid tetraethyldiamide

Binuclear non-symmetrical phosphor(???)arene macrocyclic phosphonite bearing different aromatic fragments (Ar¹ ≠Ar²) was synthesized using two different bisphenols (4,4′-iminodiphenol and 4,4′-methylenediphenol) as the starting material. The characteristic properties of the synthesized macrocycle that confirm its structure, in particular, oxidation and sulfurization reactions, were studied.

     

A Simple Sensor for Potentiometric Titrations

Abstract

A sensor for potentiometric titrations was prepared by coating a spectroscopic graphite rod with a solution of poly(vinyl chloride) and dioctylphthalate in tetrahydrofuran. The reference was a Ag/AgCl single-junction electrode. The sensor was used in the following potentiometric titrations:

1. precipitation titrations 2. acid-base titrations, 3. compleximetric titrations, and 4. redox titrations.

A survey of its use in such titrations is presented.

Preparation of the coated-graphite sensor is simple and rapid. Moreover, it is quite inexpensive. A limitation is its applicability in aqueous media only, because organic solvents will dissolve the membrane.