Stainless steels international standards

Intercrystalline corrosion was a serious problem with the austenitic stainless steels early in their development since carbon contents then were relatively high, e.g. En58J contained up to 0.12type stainless steel contained up to 0.08 Vo C. The problem in relation to surgical implants has been reported by Scales eta/. and as a result of this and several other reports the British, American and International Standards specified the use of a 316S12 type austenitic stainless steel which contains 0.03 Vo C max. The use of the lower carbon content stainless steels as specified in the various standards has now eliminated the problem of sensitisation of implants. If manufacturers do use the 0.08% C versions they have to be very careful with the forging temperatures or anneal the prostheses afterwards. 

Burdick and Jackson). All solutions were photolyzed to less than 5% conversion in a standard 3 ml capacity, 1-cm path length quartz cell. Samples were irradiated with a 450-Watt medium pressure, Hanovla mercury lamp focused through an appropriate band-pass filter (280 nm or 254 nm) onto the 1-cm quartz cell with the requisite solution. Test solutions could be purged with either helium or oxygen using a needle valve assembly attached to the tapered quartz cell neck. The loss of carbamate due to photolysis and the amounts of known photoproducts were determined quantitatively by GC using eicosane as an internal standard. The columns were 6 stainless steel containing Carbowax 20M on chromosorb G. 

General Procedure for the Hydroformylation/Electrophilic Substitution. Synthesis of 5,6-dihydroindolizines. A solution of 1-allylpyrroles (leq) and Rh4(CO)i2 (lmol%) in toluene was introduced by suction into an evacuated stainless-steel reaction vessel. CO (60 bar) was introduced, the autoclave was then rocked, heated to the desired temperature and H2 (60 bar) was introduced rapidly. When the gas absorption reached the value corresponding to the fixed conversion, the reaction mixture was siphoned out. The degree of conversion and the product distributions were determined by GC and GC-MS, by using acetophenone as an internal standard. 

The actuation chamber is made from stainless steel. It houses the canister within its adapter sleeve during dosing. A smooth surface provides a face seal between canister valve stem tip and sample injection passage. The close tolerance between the external wall of the adapter and the internal wall of the actuation chamber induces a partial vacuum which creates a controlled pumping action causing sample methanol to flush the injection passage after each dose. A replaceable 16 gauge needle fits onto a standard luer tapered tip. 

Sane et al. reported the determination of diloxanide furoate in pharmaceuticals by gas chromatography [36]. A sample of powdered tablets equivalent to 250 mg of drug was dissolved in chloroform and diluted to a concentration of 5 mg/mL. A mixture of 2 mL of the sample solution and 1 mL of bromhexine hydrochloride solution (the internal standard) was diluted to 5 mL with chloroform, was used for the analysis. The injection volume was 400 nL, which was analyzed at 265°C on a stainless steel column (3 m x 2 mm) containing 3% OV-13 on Chromosorb W-HP (80-100 mesh). Nitrogen was used as the carrier gas at a flow rate of 50 mL/min, and analyte detection was effected using a dual flame ionization detector. 

Sadana and Gaonkar have simultaneously determined diloxanide furoate and tinidazole in pharmaceutical dosage form by gas liquid chromatography [37]. Powdered tablets or suspension formulations were dissolved in chloroform, the solution filtered, and then diluted to 25 mL with chloroform. The solution also contained metronidazole as an internal standard. A 600 nL aliquot was analyzed on a stainless steel column (1 m X 3.2 mm) containing 3% of OV-17 on Chlorosorb W-UP (100-120 mesh). The GC system was operated at 200°C, using nitrogen as the carrier gas (45 mL/min). Flame ionization detection was used to observe the analytes. 

Culea et al. reported a quantitative GC-MS analysis of procaine and some neurotransmitters in rat brain tissue [94], Procaine was extracted fi om brain homogenates by the ultrasonication method of Sundlof et al. [95], and was determined in its underivatized form on a 24 m glass capillary column coated with Silar IOC (temperature programmed from 120°C to 225°C at 12°C/min with pyrene as the internal standard). It was found necessary to wash the injector liner and the GC-MS interface stainless steel tubing with 1 1 0.1 M KOH-methanol so that the interface tubing could be coated with a film of OV-17 (from acetone solution), and to condition the apparatus by injecting bis-(trimethylsilyl)-acetamide and triethylamine. 

To a solution, at — 10 X, of butadiene (85 mg, 1.57 mmol) in the weighed amount of solvent to make 0.02 mole fraction butadiene was added solid XeF2 (50 mg, 0.295 mmol). To the stirred mixture was added BFj- OEt2 (0.2 equiv with respect to XeF2). The mixture was stirred for 10-15 min and then poured into 5 % aq NaHCO, extracted with CH2C12, and dried (MgSOJ. Methylcyclohexane was added as an internal standard, and the products were analyzed (60-75 % yields) by GC (stainless steel column. 17 ft x 0.25 in.. 5% DNP on 80/100-mesh Chromosorb W). Analysis at 35X showed 3,4-difluorobut-l-ene and trans-and d.s-1,4-difluorobut-2-ene to have retention times of 4.5, 10, and 11.5 min, respectively. Products were collected by preparative vapor-phase chromatography. 

The majority of published HPLC techniques used in fat-soluble vitamin assays have utilized 5- or 10-/zm particles of porous silica or derivatized silica packed into stainless steel tubes of typical length of 250 mm and standard internal diameter (ID) of 4.6 mm. Radially compressed... 

The required heat-transfer area of 19.5 m2 is based on an overall heat-transfer coefficient of 102 W/(m2 K). The best exchanger geometry for this application includes six internal baffles, one shell-side pass and two tube-side passes. The shell is fabricated from standard carbon steel piping of nominal pipe size 30, schedule number 80. The 112 tubes required are each 1.83 m long and 38.1 mm (1.5 in.) o.d. (BWG 12). The tubes must be fabricated from stainless steel type 250 for reasons of temperature tolerance. 

The standard for on a particular kind of stainless steel is one containing 18% chromium and 8% nickel. Thus, not only the units of the International System of Units (SI units), such as mass, temperature and density, but also compositional standards can be defined by attributes or represented by reference materials. Any of these measurement standards can be referenced in technology or commerce often as a contractual or mandatory requirement. Traceability and traceable are commonly used in relation to (the value of) a material standard. 

To prepare a sample, an analyte of interest is dissolved in an appropriate solvent at a concentration of about 20 pM. This solution and a matrix solution (50 50, vol/vol) are mixed with an appropriate matrix-analyte ratio at >10 1 in a small vial. If an internal standard is used, the internal standard is dissolved in the sample solution before combining with the matrix. A tiny drop (0.5-2.0 pi) of the final solution is transferred and applied to the MADLI sample target plate which can be a stainless steel or a Gold-coated MALDI sample plate. The sample-matrix solution is allowed to dry at room temperature and under normal pressure for several minutes until all of solvents are completely evaporated. The precipitate is the cocrystallization of matrix and analyte, ready for MALDI analysis. 

The reactions were carried out in 300 ml. stainless steel Whitey reaction vessels heated for 30 minutes in a constant temperature oil bath. The come-up time to reach the oil bath temperature was shortened by preheating for 10 minutes in a 70°C water bath. After heating, the vessels and contents were cooled rapidly to about 5°C. A 100 ml aliquot of each reacted sample was adjusted to pH 10 according to Tressl et al. (6) and extracted four times with 100 ml portions of methylene chloride. The extracts were combined and concentrated to approximately 5 ml. at ambient temperature. One ml of 0.30% v/v cyclohexanone in methylene chloride internal standard was added, the samples were brought to 10.0 ml and were then filtered through 0.5 p Teflon cartridge filters. 

The estimation of individual components and different synthetics was effectively achieved by gas chromatography after simple silylation (10). Figure 2 shows the separation obtained, clearly away from other volatiles in a capsicum extract. The individual capsaicinoids were quantitated in relation to vanillyl octanamide as the internal standard chosen, because it eluted just prior to the capsaicinoids and the response factors of the capsaicinoids with reference to this standard were close to unity. The standardised conditions were as follows Silylation with N,0-bis (trimethylsilyl)-trifluoroacetamide in tetrahydrofuran gave clear rapid reaction at room temperature. The silylated extracts were injected directly on to a stainless steel column of 2 m x 3 mm, filled with 3% SE-30 on Chromosorb-GHP, (100-120 mesh) the column temperature was programmed from 170° to 215°C at 4°/min. and held at 215°C for 10 minutes. The injection port temperature was important for rapid volatilisation of all the components without decomposition, and was fixed at 200°C. The flame ionisation detector temperature was kept at 250°C, and nitrogen flow at 20 ml/min. The percentages of the individual capsaicinoids were calculated from the areas of the peaks, the response factors, and the weight and area of the reference compound. 

Wang et al. studied the stability of nimodipine by HPLC, using beclomethazone dipropionate as an internal standard [33]. The method used a stainless steel column (25 cm x 4 mm) containing YWG C18H37, which was eluted at a flow rate of 1 mL/min) with methanol-water-ethyl ether (35 15 4). Detection was effected at 238 nm. The calibration graph... 

The transfer line consists of an electrically heated stainless steel tube, through which an uncoated, yet deactivated fused silica transfer capillary is passed until the end of the plasma injector. All parts of the stainless steel transfer tube are heated, including the part inside the torch box. The ICP-MS instrumentation is prone to signal suppressions and/or instrumental drift. These problems can be compensated by the use of internal standards. In the case of GC-ICP-MS the internal standard can be added to the carrier gas of the GC apparatus. A suitable internal standard is Xenon (Xe) [41]. The 126Xe signal is monitored simultaneously with the other isotopes of interest. In this way instrumental drift and signal suppression can be corrected. 

Methanol and an internal standard (acetonitrile or benzene) can be determined with a 2m x 6mm stainless column packed with 30% Triton X-100 on chromosorb W (Gierer et al. 1964, Yang and Goring 1980) or with a 1.8m x 0.32 cm stainless steel column packed with Tenax GC (Lai et al. 1990). The Triton column is available from Supelco Chromatography Products, Bellefonte, PA, while the Tenax column may be obtained from Alltech Associates, Inc., Deerfield, IL. Both columns are operated at 80 °C with an injection port temperature of 150 °C and a detector temperature of 250 °C. A nitrogen flow of 30 ml min-1 is maintained. 

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