Application Finder
- 8.000.6013Analysis of produced water contaminants by ion chromatography
The analytical challenge treated by the present work consists in detecting sub-ppm quantities of bromide, sulfate, aliphatic monocarboxylic acids and several alkaline earth metals in the presence of very high concentrations of sodium and chloride. Bromide, sulfate, acetate and butyrate can be reliably determined by suppressed conductivity detection. Due to matrix effects, propionate can only be detected qualitatively. This drawback can be overcome by coupling the ion chromatograph (IC) to a mass spectrometric (MS) detector. This results in reduced matrix interferences and significantly enhanced sensitivities. The cations magnesium, barium and strontium are determined by non-suppressed conductivity detection.
- 8.000.6066Determination of the total acid number (TAN) using thermometric titration
The thermometric titration method presented here permits a simple and direct determination of the total acid number (TAN) in petroleum products. It is an invaluable alternative to current manual and potentiometric methods. Thermometric titration uses a maintenance-free temperature sensor that does not require rehydration and is free of fouling and matrix effects. The procedure requires minimal sample preparation. Results agree closely with those from the potentiometric titrimetric procedure according to ASTM D664, but the thermometric titration method is far superior in terms of reproducibility and speed of analysis, with determinations being complete in approximately one minute.
- AB-042Determination of carbonyl compounds by potentiometric titration
Carbonyl compounds (CC) occur in many products, such as bio-oils and fuels, cyclic and acyclic solvents, flavors and mineral oils. Carbonyl compounds can be responsible for the instability of these products during storage or processing. Especially pyrolysis bio-oils are known to cause issues during storage, handling and upgrading. This bulletin describes an aqueous and a non-aqueous analytical titration method for the determination of carbonyl compounds by potentiometric titration.
- AB-050Determination of lead in petroleum products by stripping voltammetry
The determination of the lead content in engine fuels has gained considerable importance since the introduction of the catalytic converter technique. Even small contents of lead interfere with the effectiveness of the catalysts or may destroy them. On the other hand, there are still many vehicles on the roads which run on leaded fuel (addition of tetraalkyl lead). Here also the knowledge of the lead content is of interest.With reference to DIN 51769 and ASTM 0-1269 a simplified procedure for the determination of lead in petrochemical products is described. The products are digested with HCl and the lead compounds are converted to lead(II) chloride. After extraction with water, the inverse voltammetric Pb determination is carried out.
- AB-077Volumetric water content determination according to Karl Fischer – Tips and tricks for volumetric Karl Fischer titration
This Application Bulletin gives an overview of the volumetric water content determination according to Karl Fischer. Amongst others, it describes the handling of electrodes, samples, and water standards. The described procedures and parameters comply with the ASTM E203.
- AB-102Conductometry
This bulletin contains two parts. The first part gives a short theoretical overview while more details are offered in the Metrohm Monograph Conductometry. The second, practice-oriented part deals with the following subjects:Conductivity measurements in general; Determination of the cell constant; Determination of the temperature coefficient; Conductivity measurement in water samples; TDS – Total Dissolved Solids; Conductometric titrations;
- AB-130Chloride titrations with potentiometric indication
Potentiometric titration is an accurate method for determining chloride content. For detailed instructions and troubleshooting tips, download our Application Bulletin.
- AB-135Potentiometric determination of hydrogen sulfide, carbonyl sulfide, and mercaptans in petroleum products
This Bulletin describes the potentiometric determination of hydrogen sulfide, carbonyl sulfide, and mercaptans in gaseous and liquid products of the oil industry (natural gas, liquefied petroleum gas, used absorption solutions, distillate fuels, aviation gasoline, gasoline, kerosene, etc.). The samples are titrated with alcoholic silver nitrate solution using the Ag Titrode.
- AB-137Coulometric water content determination according to Karl Fischer
This Application Bulletin gives an overview of the coulometric water content determination according to Karl Fischer.Amongst others, it describes the handling of electrodes, samples, and water standards. The described procedures and parameters comply with the ASTM E1064.
- AB-142Karl Fischer water determination in gases
This Application Bulletin describes the determination of water in non-explosive and non-flammable gaseous samples using the coulometric Karl Fischer method. This method is ideal for very low water contents.
- AB-177Automatic determination of the bromine number and the bromine index in petroleum products
The bromine number and bromine index are important quality control parameters for the determination of aliphatic C=Cdouble bonds in petroleum products. Both indices provide information on the content of substances that react withbromine. The difference between the two indices is that the bromine number indicates the consumption of bromine in gfor 100 g sample and the bromine index in mg for 100 g sample.This Application Bulletin describes the determination of the bromine number according to ASTM D1159, ISO 3839, BS2000-130, IP 130, GB/T 11135 and DIN-51774-1. The bromine index determination for aliphatic hydrocarbons is described according to ASTM D2710, IP 299, GB/T 11136 and DIN 51774-2. For aromatic hydrocarbons the determination of the bromine index is described according to ASTM D5776 and SH/T 1767. UOP 304 is not recommended for the determination of the bromine number or bromine index because its titration solvent contains mercuric chloride.
- AB-178Fully automated analysis of water samples
The determination of the physical and chemical parameters as electrical conductivity, pH value, p and m value (alkalinity), chloride content, the calcium and magnesium hardness, the total hardness, as well as fluoride content are necessary for evaluating the water quality. This bulletin describes how to determine the above mentioned parameters in a single analytical run.Further important parameters in water analysis are the permanganate index (PMI) and the chemical oxygen deman (COD). Therefore, this Bulletin additionally describes the fully automated determination of the PMI according to EN ISO 8467 as well as the determination of the COD according to DIN 38409-44.
- AB-188pH measurement technique
This Bulletin, using practical examples, indicates how the user can achieve optimum pH measurements. As this Bulletin is intended for actual practice, the fundamentals - which can be found in numerous books and publications - are treated only briefly.
- AB-209Water in insulating oils, hydrocarbons, and their products – Accurate and reliable determination by Karl Fischer titration
Only coulometric Karl Fischer titration can determine low water contents with sufficient accuracy.This Application Bulletin describes the direct determination according to ASTM D6304, ASTM E1064, ASTM D1533, ASTM D3401, ASTM D4928, EN IEC 60814, EN ISO 12937, ISO 10337, DIN 51777, and GB/T 11146. The oven technique is described according to ASTM D6304, EN IEC 60814, and DIN 51777.
- AB-322Fully automated potentiometric determination of the hydroxyl number (HN) according to ASTM E1899 and DIN EN ISO 4629-2
The presented titration system can be used for the fully automated determination of the hydroxyl number (HN) according to ASTM E1899 and EN ISO 4629-2. The method allows, the determination of polyols and oxooils without boiling under reflux or other sample preparation and is therefore a big benefit for laboratories that have to cope with a high sample throughput.The standards EN 15168 and DIN 53240-3 relay on the same analysis method as in ASTM E1899.
- AB-340Bromine index (BI) by coulometric titration
This bulletin describes a procedure to determine the bromine index (BI) using coulometric titration. The bromine index is the fraction of reactive unsaturated compounds (mostly C=C double bonds) in hydrocarbons encountered in the petrochemical industry. The double bonds are split with the attachment addition of bromine.
- AB-404Total acid number titration of petroleum products
The determination of the acid number plays a significant role in the analysis of petroleum products. This is manifested in the numerous standard procedures in use over the world (internal specifications of multinational companies, national and international specifications of ASTM, DIN, IP, ISO, etc.). These procedures differ mainly in the composition of the used solvents and titrants.This bulletin describes the determination of the acid number in petroleum products by applying different types of titration.The potentiometric determination is described according to ASTM D664, the photometric according to ASTM D974 and the thermometric titration according to ASTM D8045.
- AN-C-164Amine analysis in gas scrubber solutions from refineries with direct conductivity detection
In natural gas production, the removal of contaminants, and in particular acidic gases such as H2S and CO2, is exceptionally important. These acidic gases are removed in the amine wash through chemical treatment with amines or alkanol amines. This application shows a convenient and precise analysis with the separation of various amines and standard cations on a column of the Metrosep C 6 - 250/4.0 type with subsequent direct conductivity detection.
- AN-C-170N-methyldiethanolamine, piper-azine and standard cations in scrubber solutions
N-methyldiethanolamine and piperazine are used in scrubber solutions, e.g., in the natural gas process. Testing this type of samples by ion chromatography requires a good resolution and the separation of amines from standard cations. The separation is achieved on a Metrosep C 4 - 150/4.0 column applying direct conductivity detection.
- AN-C-171N-methyldiethanolamine and piperazine in scrubber solution
Before the liquefaction process of the natural gas, carbonate and hydrogen sulfide need to be removed through a scrubber solution containing piperazine and N-methyl diethanolamine (MDEA). The concentration ratio of the two components is determined by ion chromatography on a Metrosep C 4 - 150/4.0 column applying direct conductivity detection.
- AN-C-180Bicine in gas sweetening solvent by cation chromatography
Bicine (2-(Bis(2-hydroxyethyl)amino)acetic acid) is a corrosive component. It has to be avoided in acidic gas sweetening solvents. These solvents are based on organic amines. Bicine is amphoteric, holding a carboxylic and an amine group. Under the applied conditions, the amine groups are at least partially protonated and therefore may be separated by cation chromatography. The detection mode is direct conductivity detection.
- AN-C-193Alkyl amines in scrubber solutions
Harmful industrial flue gases like H2S and CO2 cause corrosion of pipes and damage the environment. Adding the correct amount of amines in scrubber solutions, e.g. ethanolamines and methylamines, will neutralize these gases («gas sweetening»). Non-suppressed cation analysis with direct conductivity detection is a straightforward and robust technique for the quantification of monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), monomethylamine (MMA), dimethylamine (DMA), and trimethylamine (TMA) via ion chromatography. Thanks to the high capacity of the Metrosep C 6 column, large volumes can be injected without compromising the peak shapes. The analytical technique can be used at laboratory scale but also for process analysis.
- AN-CIC-001Halogens in high-viscosity oils using Combustion IC
Determination of chloride and sulfate (non-quantified) in a high-viscosity oil sample using combustion digestion and subsequent anion chromatography with conductivity detection following sequential suppression.Keyword: pyrohydrolysis
- AN-CIC-014Chloride traces in the wax fraction of crude oil distillation using Metrohm Combustion IC
Paraffin and lubricating oils are yielded from the wax fraction of raw oil distillation. The chloride content of both should be low. This Application Note describes chloride determination after inline combustion. Although it does not happen in this application, this method can also be used to quantify the sulfur content.Keyword: pyrohydrolysis
- AN-CIC-018Halogens in liquefied gas with Metrohm Combustion IC and LPG/GSS module for sampling
This Note addresses the determination of the fluorine and chlorine content of a liquefied gas sample (LPG, Liquid Petroleum Gas), i.e. halogens in a mixture of propane and butane. Fluorine originates from perfluorobutane and chlorine from methyl chloride. LPG/GSS modules are used to introduce 50 µL of sample into the combustion system. The halogens released during combustion are determined using ion chromatography with intelligent partial loop injection technique following Inline Matrix Elimination.Keyword: pyrohydrolysis
- AN-CIC-024Organic chloride in naphtha fraction of crude oil distillation according to ASTM D8150
The content of organic chloride in crude oil is determined according to ASTM D8150 in the naphtha fraction after distillation. The naphtha fraction is washed with caustic and water, respectively, to remove hydrogen sulfide and inorganic halides. Here, the determination of organic chloride after inline combustion is presented. Although the sulfur content was of no interest in this application, the same setup allows sulfur quantification.
- AN-CIC-031Sulfur determination in ammonia gas applying Combustion IC
Sulfur species are critical contaminants in ammonia gas. They can cause high-temperature sulfidation of metals, form aggressive complexes with other elements, or react subsequently in processes where the ammonia gas is used. The concentration of such impurities tends to be very low, but they may not exceed critical levels of 0.5 mg/L. Although this level is very close to the system blank of the Combustion IC system, the setup can be used to prove that such critical limits are not exceeded.
- AN-COR-001Corrosion part 1 – basic concepts
Corrosion refers to a process that involves deterioration or degradation of metal. The most common example of corrosion is the formation of rust on steel. Most corrosion phenomena are of electrochemical nature and consist of at least two reactions on the surface of the corroding metal.
- AN-COR-002Corrosion Part 2 – Calculation of Corrosion Parameters with NOVA
Electrochemical methods provide an alternative to traditional methods used to determine the rate of corrosion. For example, corrosion rates, the rates at which a specimen corrodes, can be calculated from simple electrochemical measurements like a linear sweep voltammetry (LSV).
- AN-COR-003Measurement of polarization resistance
Polarization resistance (Rp) can quantify the corrosion resistance of metals as an alternative to Tafel analysis. Its methodology and practical use as described in ASTM G59 are discussed.
- AN-COR-004Corrosion part 4 – equivalent circuit models
Electrochemical impedance spectroscopy or EIS has been used effectively to measure the polarization resistance for corrosion systems and for the determination of corrosion mechanisms.
- AN-COR-005Corrosion part 5 – corrosion Inhibitors
A corrosion inhibitor is a substance that reduces the corrosion rate of a metal. A corrosion inhibitor is usually added in a small concentration to the corrosive environment. This application note shows how Metrohm Autolab instruments can be used to check the quality of inhibitors.
- AN-COR-006Critical Pitting Temperature (CPT) as per ASTM G150
This Application Note is based on the ASTM standard G150, developed to test the resistance of stainless steel, and otheralloys related to stainless steel, on pitting formation at elevated temperature. This is achieved by determining the potential-independent critical pitting temperature (CPT), defined as the lowest temperature at which pitting evolution occurs. The CPT experiment consists of applying a potential to the specimen while the cell temperature is raised and recording the current.
- AN-COR-011ASTM G100: Cyclic Galvanostaircase Polarization
The ASTM standard G100 is an electrochemical method to test localized corrosion of aluminum 3003-H14 and other alloys. A cyclic galvanostatic staircase polarization (galvanostaircase) is composed of an upward and a downward scan. The potential values at the end of each step are collected and linearly fitted, and the potential values at zero current are found.
- AN-COR-012ASTM G5: Potentiodynamic anodic polarization measurements
This Application Note evaluates corrosion in Type 430 stainless steel according to ASTM G5 with VIONIC powered by INTELLO and an ASTM-compliant corrosion cell setup.
- AN-COR-014Corrosion Inhibitor Efficiency Measurement in Turbulent Flow Conditions with the Autolab Rotating Cylinder Electrode (RCE), According to ASTM G185
The rotating cylinder electrode (RCE) is a technique used in corrosion research to simulate in a laboratory environment the turbulent flow which usually occurs when liquids are transported through pipelines. The RCE is used to generate a turbulent flow at the surface of a sample, simulating the pipe flow conditions. Experiments that involve an RCE are regulated by the ASTM G185 standard. In this application note, The RCE with a 1018 carbon steel cylinder sample was used with the linear polarization (LP) measurement technique.
- AN-COR-015Corrosion Rates Measurements in Quiescent and Turbulent Flow conditions by using Rotating Cylinder Electrode (RCE)
The rotating cylinder electrode (RCE) is successfully used in a laboratory environment to generate a turbulent flow at the surface of a sample, simulating realistic pipe flow conditions. In this application note, the corrosion rate is measured and compared between quiescent and turbulent flow conditions, while keeping all the other experimental conditions unchanged. The linear polarization (LP) technique was used together with the RCE (with and without rotation).
- AN-COR-019Determining the corrosion rate with INTELLO
Tafel analysis is an important electrochemical technique used to understand reaction kinetics. By studying the Tafel slope, it reveals the rate-determining steps in electrode reactions, aiding fields like corrosion and fuel cell research. This method helps industries optimize processes and improve device performance by tailoring materials and conditions for greater efficiency.
- AN-EC-028Measuring hydrogen permeation according to ASTM G148
In this Application Note, hydrogen permeation experiments are conducted following the procedure described in the ASTM standard G148.
- AN-EC-032Hydrogen permeation with a single instrument according to ASTM G148
The Devanathan-Stachurski cell (or «H cell») is successfully used to evaluate the permeation of hydrogen through sheets or membranes. As small amounts of hydrogen pass through the sheet or membrane, a very sensitive potentiostat is required for its detection. A study of the hydrogen permeation properties of different iron sheets is discussed in this Application Note while taking the instrumental requirements into account.
- AN-EIS-001Electrochemical impedance Spectroscopy (EIS) Part 1 – Basic Principles
Electrochemical impedance spectroscopy (EIS) is a widely used multidisciplinary technique for characterizing the behavior of complex electrochemical systems. EIS is employed in the study of a range of complex systems including batteries, catalysis, and corrosion processes. This Application Note focuses on the basic principles of EIS measurements.
- AN-EIS-002Electrochemical Impedance Spectroscopy (EIS) Part 2 – Experimental Setup
A typical electrochemical impedance spectroscopy (EIS) experimental setup consists of an electrochemical cell, a potentiostat/galvanostat, and a frequency response analyzer (FRA). This Application Note introduces common EIS experimental setups as well as details of the main experimental parameters.
- AN-EIS-004Electrochemical Impedance Spectroscopy (EIS) Part 4 – Equivalent Circuit Models
Explore how to construct simple and complex equivalent circuit models for fitting EIS data in this Application Note. Nyquist plots are shown for each example.
- AN-H-012Determination of ferrous ion content of heat exchanger wash solutions
Determination of ferrous ions in heat exchanger and vessel acid wash solutions, for measuring the effectiveness of acid inhibitors used in the solutions. Depending on the condition of the sample, the lower practical limit for the determination will vary from approximately 20-100mg/Kg Fe2+. Samples with high silicic acid contents require relatively large amounts of dilution water to render them mobile, and this limits the aliquot size and hence the amount of Fe2+ which can be analyzed.
- AN-H-024Determination of tar acids (phenolics) in tar products
Determination of tar acids in coal tar products. This procedure may also be applied to the determination of a range of weakly acidic organic compounds such as carboxylic acids, hydroxy acids, phenols, phenolic acids, keto-enols, imides, and aromatic nitro compounds.11 Vaughan, G. A. Thermometric and Enthalpimetric Titrimetry. Van Nostrand Reinhold Co. Ltd (1973)
- AN-H-079Determination of free acid in heat exchanger cleaning acid
Determination of free acid in sulfuric acid («acid shot») solutions employed in the removal of silicate scale in heat exchangers. This method is suitable for acid shot solutions where the silicic acid content is so high that the solutions have gelled.
- AN-K-067Determination of the bromine index of aromatic hydrocarbons by coulometric titration according to ASTM D1492
The bromine index indicates the degree of unsaturation and relies on the simple addition of bromine to the double bond of alkenes. One mole of bromine is consumed for each mol of carbon-carbon double bond. The bromine index indicates the olefin content in aromatic hydrocarbons. This Application Note describes the determination by coulometric titration according to ASTM D1492.
- AN-K-070Water in petroleum products
Moisture in petroleum products causes several issues: corrosion and wear in pipelines and storage tanks, an increase in debris load resulting in diminished lubrication, blocked filters, or even harmful bacterial growth. As a result, increased water content can lead to infrastructure damage, higher maintenance costs, or even unwanted downtimes.Coulometric Karl Fischer titration is the method of choice for low water content in petroleum products. Using a Karl Fischer oven to vaporize the water present in the sample prior to titration not only greatly reduces matrix interferences, it can also be fully automated. This allows a reliable and cost-efficient analysis of the water content according to ASTM D6304 (Procedure B) in products such as diesel, hydraulic oil, lubricant, additive, turbine oil, and base oil.
- AN-K-074Water content in crude oil determined with Karl Fischer titration
To determine water in crude oil, ASTM D4928 recommends coulometric Karl Fischer titration with the oven method, allowing full automation for high reproducibility.
- AN-M-001Aliphatic monocarboxylic acids in produced water using IC/MS coupling
Determination of acetic, propionic, butyric, valeric, and caproic acid in produced water using anion chromatography with conductivity and MS detection after post-column addition of ammonia for MS detection and inline sample preparation by dialysis.
- AN-M-003Phosphate in produced water using IC/MS coupling after sample preparation by inline dialysis
Determination of phosphate in produced water containing up to 100 g/L chloride as well as crude oil using anion chromatography with conductivity and MS detection after inline dialysis.
- AN-O-017Glycolic acid, formic acid, acetic acid and carbonic acid in a scrubber solution
Determination of glycolic acid, formic acid, acetic acid and carbonic acid in a scrubber solution using ion-exclusion chromatography with conductivity detection after chemical suppression.
- AN-O-035Acetate and formate in amine solutions
Determination of acetate and formate in an amine solution using anion chromatography with conductivity detection after suppression.
- AN-O-045Organic acids in monoethylene glycol by ion-exclusion chromatography with inverse suppression
Monoethylene glycol (MEG) is used to remove water from natural gas before further processing. Due to high temperatures applied, glycol degradation to glycolic, formic, and acetic acid may occur. These reactions are unwanted as the emerging acids are corrosive. The determination of the organic acids is achieved by ion-exclusion chromatography with conductivity detection after inverse suppression.
- AN-O-046Organic acids in gas sweetening solvent by ion-exclusion chromatography with inverse suppression
Acidic gas sweetening solvents are used to remove acid gases such as H2S and CO2 from streams. Typically, amines are applied as alkaline components in these solvents. The determination of organic acids (glycolic, acetic, formic, propionic, and butyric acid) is achieved by ion-exclusion chromatography with conductivity detection after inverse suppression.
- AN-P-052Trace analysis of cyanide and sulfide in aqueous samples – DC amperometric determination after ion chromatographic separation
Sulfide and cyanide are toxic anions. Their trace determination in any kind of water samples, especially in wastewater, is requied for safety reasons. However, metal traces present in the eluent can mask target anions due to complexation. The addition of a stronger complexing agent to the eluent mask these metal cations enabling interference free determaination. This application is mainly used for the analysis of cyanide and/or sulfide in water. However, it also fulfills the requirements of ASTM D2036 for the determination of total, amenable, weak acid dissociable cyanides. The determination of cyanide and sulfide require an alkaline eluent and amperometric detection. This Application Note describes a new column/eluent combination for optimized separation. The combination consists of the Metrosep A Supp 10 - 100/4.0 column and a sodium hydroxide eluent containing a trace of EDTA for transition metal complexation. This yields in better peak shape and detection limits below 0.1 μg/L.
- AN-PAN-1001Online analysis of hydrogen sulfide and ammonia in sour water stripper
This Process Application Note details the simultaneous online analysis of H2S and NH3 in sour water which was previously treated in the sour water stripper (SWS). The method includes automatic cleaning and calibration. Fast and accurate results are continuously supplied for process control.
- AN-PAN-1003Online analysis of amines concentration in carbon capture plants
Carbon capture systems strip carbon dioxide from flue gases. Online analysis of amines and carbon dioxide enhances amine usage efficiency and reduces operational costs.
- AN-PAN-1014Automated online determination of salt in crude oil according to ASTM D3230
Automated online analysis with the 2060 TI Ex Proof Process Analyzer facilitates constant monitoring of the crude oil desalting process according to ASTM D3230.
- AN-PAN-1026Mercaptans and hydrogen sulfide in raw oil in accordance with ASTM D3227 and UOP163
Online mercaptan and H₂S monitoring with the 2060 TI Ex Proof Analyzer certified for Zone-1 and Zone-2 areas.
- AN-PAN-1037Online measurement of the acid number (AN) in oils with thermometric titration (ASTM D8045)
Online acid number analysis in various oil products is possible with thermometric catalytic titration according to ASTM D8045 using the 2060 TI Ex Proof Process Analyzer.
- AN-RS-050Trace detection of mercaptans in fuel
Mercaptans in fuels are corrosive and regulated at trace levels. SERS enhances Raman signals to enable their accurate detection and quantification below standard LODs.
- AN-S-144Heat stable salts in a scrubber solution
Determination of chloride, bromide, nitrate, sulfite, sulfate, phosphate, oxalate, thiosulfate, and thiocyanate (heat stable salts) in scrubber solutions using anion chromatography with conductivity detection after chemical suppression.
- AN-S-24914 anions in an industrial process water
Determination of fluoride, acetate, propionate, formate, butyrate, chloride, nitrite, bromide, nitrate, benzoate, phosphate, sulfate, malonate, and oxalate in an industrial process water using anion chromatography with conductivity detection after sequential suppression.
- AN-S-261Chloride, nitrate, and sulfate in produced water
Determination of chloride, nitrate, and sulfate in produced water using anion chromatography with conductivity detection after chemical suppression.
- AN-S-268Halogens in petroleum coke after microwave combustion
Determination of fluoride, chloride, bromide, and iodide in petroleum coke after microwave combustion using anion chromatography with conductivity detection after sequential suppression.
- AN-S-343Heat-stable salts in an MDEA scrubber solution
Hydrogen sulfide (H2S) and carbon dioxide (CO2) are disruptive byproducts of natural gas that must be eliminated during conveyance. This is accomplished with the aid of gas scrubbing, during which the gas flow is cleaned with absorbers such as alkanolamines or akylalkanolamines (e.g., methyldiethanolamine, MDEA). Reliable analysis is imperative, given that heat-stable salts often accumulate in the absorber and thus inhibit the absorption capacity for acid gases.The determination of heat-stable salts (SCN–, S2O32–, SO32–, SO42–, etc.) in MDEA solutions takes place on the Metrosep A Supp 5 - 250/4.0 column with conductivity detection following sequential suppression.Key words: amine gas treating, scrubber
- AN-S-377Anions in high ionic water by IC using tandem conductivity and UV detection
«High ionic water» is typically water containing a high concentration of chloride (e.g. seawater, brine), but this also describes water samples resulting from petrochemical processes. Due to the high chloride concentrations, the conductivity determination of minor ionic components is limited. Thus, minor anions like nitrite, bromide, and nitrate can elute under or on the tail of the large chloride peak, and their detection in low concentrations is hampered. However, combining conductivity and UV/VIS detection as described in ASTM D8234 enables the determination of anions that are UV active. Chloride does not interfere in this situation. The described technique enables the interference-free simultaneous determination of trace anions besides high chloride content.
- AN-S-378Anions in refining process water applying tandem conductivity and UV detection
ASTM D8234 describes the determination of anions in high saline water by applying suppressed conductivity followed by UV/VIS detection. This combination enables the determination of e.g. nitrite by UV detection. With conductivity detection, this quantification is not possible or difficult due to the very large chloride peak. The actual sample is a refining process liquid with a high chloride content. As the sample solution also contains organic material, Inline Dialysis is applied to protect the analytical column. The combination of the two detection modes and the Inline Dialysis option reduces manual sample preparation and substantially increases the accuracy of the analysis.
- AN-S-389Heat-stable salts in monoethanolamine (MEA) for gas sweetening
In the petrochemical industry, natural gas is processed to remove contaminants and meet product specifications. Process contaminants include acidic gases such as hydrogen sulfide and carbon dioxide, which can corrode costly refinery equipment downstream. Typically, the acidic gases are removed via alkanolamine treatment using monoethanolamine (MEA) or methyldiethanolamine (MDEA). The amine solutions absorb the acidic gases, and then the amine compounds are removed from the natural gas. In addition to the acidic gases, heat stable salts (HSS) that remain in the natural gas are also corrosive to the treatment plants. These are also removed via gas sweetening and need to be determined in the used gas sweetening amine solution. Some typical heat stable salts of interest include acetate (1), formate (2), chloride (3), phosphate (4), sulfate (5), oxalate (6), thiosulfate (7), and thiocyanate (8).
- AN-T-028Hydrogen sulfide and mercaptans in petroleum products
Simultaneous determination of hydrogen sulfide and mercaptans in petroleum products by potentiometric titration with silver nitrate using the Ag-Titrode.
- AN-T-032Sulfide and hydrogen sulfide in water
This Application Note presents a potentiometric titration method for trace H2S analysis in water on an OMNIS system using silver nitrate and an Ag Titrode.
- AN-T-043Bromine index in low-level standards
Determination of the bromine index in low-level standards by bivoltametric titration with bromide/bromate using a double Pt electrode.
- AN-T-172Determination of alkalinity in brackish water, seawater and brine in accordance with ASTM D3875
Alkalinity is well-suited as a means of describing the capacity of a body of water to neutralize acid contaminations. It is therefore an important indicator for estimating the influence of contaminations on the ecological system.
- AN-T-182Determination of the bromine number in petroleum products and aliphatic olefins according to ASTM D1159
The bromine number is an important parameter for the determination of aliphatic C=C double bonds in petroleum products. The bromine number is usually determined using electrochemical titration at 5 °C, where the bromine is generated in situ from a bromide/bromate solution. For the titration, a solvent mixture of glacial acetic acid, methanol, and chloroform is used. In this Application Note, the toxic chloroform was replaced with diethyl carbonate.
- AN-T-187Bromine number in petroleum distillate
The bromine number indicates the degree of unsaturation and relies on the simple addition of bromine to the double bonds of alkenes. One mole of bromine is consumed for each mole of carbon-carbon double (C=C) bond present in a substance. In petroleum products, the bromine number corresponds to the olefin content.Normally, chlorinated solvents are used for the determination of the bromine number. In this Application Note they have been replaced by toluene. This makes the determination more ecological. The titration is performed automatically on an OMNIS system in combination with a double Pt-wire electrode. With this setup, a fast and accurate determination by potentiometric titration can be realized.
- AN-T-190Determination of carbonyl compounds in oils by potentiometric titration
Carbonyl compounds occur in many products such as bio-oils and fuels, solvents, flavors, and mineral oils. Carbonyl compounds are often prone to oxidation and thus their content has an influence on stability during storage or processing. Especially for pyrolysis bio-oils, stability issues are observed during storage, handling, and upgrading.Oils are dissolved in isopropanol. After a reaction with the hydroxylamine hydrochloride at 50 °C, a fast and accurate determination by potentiometric titration using the dSolvotrode and tetra-n-butylammonium hydroxide as titrant is performed.
- AN-T-203Acidity in volatile solvents and chemical intermediates
The presence of acidic components in volatile solvents could be a result of contamination, decomposition during storage, distribution or manufacture. An increased acid content in solvents could lead to a variety of problems like shorter storage stability or chemical corrosion. Using the Optrode for indication, the acidity is determined by photometric titration with sodium hydroxide as titrant and phenolphthalein as indicator. If the volatile solvent is water soluble, it is dissolved in deionized water, if not, it is dissolved in carbon-dioxide free ethanol.
- AN-T-205Fully automated water analysis by OMNIS
The determination of the physical and chemical parameters as electrical conductivity, pH value, alkalinity, the calcium and magnesium hardness as well as the total hardness are necessary for evaluating the water quality. A fast and accurate determination in tap water is realized using an automated OMNIS System working in parallel on different workstations. An 856 Conductivity Module with Dosinos extends the system.
- AN-T-206Bromine index of petroleum-based hydrocarbons
The bromine index is an important parameter for the determination of aliphatic C=C double bonds in petroleum hydrocarbons. For the titration, a solvent mixture of glacial acetic acid, methanol, and dichloromethane is usually used.In this Application Note, the chlorinated solvent in the solvent mixture was replaced with toluene, resulting in a more environmentally beneficial method in comparison to ASTM D2710 and IP 299.
- AN-U-024Vanadium speciation using ion chromatography with UV/VIS detection
Determination of vanadium(IV) and vanadium(V) in Benfield solution using anion chromatography with UV detection.
- AN-U-072Speciation of vanadium(IV) and vanadium(V) as EDTA complexes in Benfield solution applying UV/VIS detection
The Benfield Process is a well known procedure to remove H2S and CO2 from petroleum and industrial gases. Vanadium pentoxide is added as a corrosion inhibitor and is most effective in a certain V(IV)/V(V) ratio. Therefore, speciation and determination of V(IV) and V(V) is important. This speciation is easily achieved on A Metrosep A Supp 5 - 50/4.0 column with EDTA as an eluent and UV/VIS detection at 282 nm.
- WP-008Coupling of ion chromatography and plasma mass spectrometry
The coupling of ion chromatography and inductively coupled plasma mass spectrometry (ICP/MS) leads to a high-performance measurement system that masters several particularly challenging analyses. It enables for example reliable determination of element compositions, oxidation states and chemical bonds. This information is used, for example, for assessing the toxicity of medications, environmental and water samples as well as foods and beverages.
- WP-037Simplifying quality control using Near-Infrared Spectroscopy
Quality control is impacted by multiple challenges, which can have an influence on the functioning of the QC lab. The present White Paper provides approaches, how to simplify the daily quality control using near-infrared spectroscopy combined with a dedicated smart software like Vision Air.
- WP-044Fundamentals of Electrochemical Corrosion Research
Free white paper describes the effective use of electrochemical techniques to measure corrosion and the effectiveness of inhibitors.
- WP-053Determination of Acid Number (AN) with Titration and NIR Spectroscopy
The acid number (AN) is a measure for the quality of oils and their potential to enhance corrosion. When analyzing fresh, unused oils, the AN is used to ensure the specified quality from the manufacturer, whereas for used oils the AN is determined to observe its increase until a critical level is reached. Although it is generally assumed that the AN correlates to the corrosive potential of the oil, this is not exactly correct, as it is the change of the AN value which indicates this issue. Therefore it is necessary to determine the AN on a regular basis.Several standards already exist to determine AN via titration methods, however it is also possible to measure this parameter via spectroscopic (NIRS) methodology. No matter which technique you choose, Metrohm has you covered with high-performance instruments suitable for these published norms.
- WP-055Corrosion Best Practice – Creating Pipe-flow Conditions Using a Rotating Cylinder Electrode
Electrochemical measurements utilizing a rotating cylinder electrode (RCE) are widely used in industrial corrosion applications when simulation of realistic pipe conditions are necessary in a lab environment. This white paper allows further insight into the particularities and parameters which govern the electrochemical measurements, in particular measurements performed in turbulent flow conditions, and shows a complete picture of the best practice use of this technique. The annexes provide an overview and short explanation of the parameters and laws specific to the fluid behavior in electrochemical cells with RCE.
- WP-061Moisture in petroleum products according to ASTM D6304
Knowledge of the water content in lubricating oils, additives, and similar products is important in the manufacturing, purchase, sale, or transfer of petroleum products to help estimate their quality and performance characteristics. Monitoring the water content in such products can prevent damage to infrastructure and ensure safe operation by avoiding corrosion processes and subsequent engine wear. This White Paper explains the easy determination of moisture in petroleum samples by coulometric Karl Fischer titration according to the three procedures outlined in ASTM Method D6304. A comparison is given between the procedures to determine which is most suitable for different sample types.
- WP-069(Un)Grounded: Grounded and floating measurements and their application in electrochemical research
In this White Paper, details of the electronic (PGSTAT) and electrochemical cell grounding are presented together with the necessity of using a floating PGSTAT for different application and experimental examples. Due to the wide variation of experimental requirements and kinds of electrochemical cells, the use of an electrochemical instrument with a selectable floating feature (such as VIONIC) which brings additional versatility to the user is recommended.
- WP-082Measuring inorganic cations and amines with ion chromatography mass spectrometry (IC-MS)
This white paper presents IC-MS as powerful analysis technique. This multiparameter method determines various analytes such as inorganic cations and amines in one run.
- WP-097Why switch to OMNIS Client/Server (C/S)?
OMNIS Client/Server boosts business performance with scalable server management, cutting costs by reducing hardware, energy use, and maintenance across locations.