Chromium Content of Total Parenteral Nutrition Solutions YASUSHI ITO, M.B., , NANCY W. ALCOCK, PH.D.,* † From the

AND

MAURICE E. SHILS, M.D., SC.D.*

Departments of Medicine, Memorial Sloan-Kettering Cancer Center and *Cornell University Medical College, New York, New the Department of Preventive Medicine and Community Health, University of Texas Medical Branch, Galveston, Texas †

ABSTRACT. Chromium (Cr) present as contaminant was analyzed by flameless atomic absorption spectrometry in a variety of commercially produced solutions and additives commonly used in total parenteral nutrition (TPN) formulas. Total Cr likely to be administered unintentionally per day was estimated both by summing the Cr in appropriate volumes of each solution required for preparation of standard TPN formulas and by analyzing complete TPN solutions. Storage of TPN

Trivalent chromium (Cr)

deficiency

York and

solutions in plastic bags for 14 days did not affect Cr concentrations. The amounts ranged from 2.4 to 8.1 μg/day for a high glucose formula and 2.6 to 10.5 μg for a high lipid formula. Amino acid solutions, especially when containing phosphate, or with phosphate salt additives and with lipid emulsions accounted for approximately 85 to 90% of the Cr found. (Journal :610-614, 1990) of Parenteral and Enteral Nutrition 14

range of the working Cr standards used. No consistent changes in concentrations were found between non-fro-

is documented in

term TPN whose formulas consmall amounts of added Cr. 1-3 In 1979, an

patients receiving long-

tained no or AMA expert panel suggested that stable adult long-term TPN patients receive 10 to 15 pg Cr daily.’ Accordingly, Cr is routinely added to TPN formula. However, data are limited on the quantities of this ion present as contaminant in the basic parenteral solutions and mineral and vitamin additives5-lo (Table I). This information is important since the quantity of chromium existing in those TPN solutions as a contaminant may be sufficient, or possibly even excessive, for some TPN patients. The need for such data is underscored by the difficulties and lack of precise data on Cr levels in serum and tissues of patients restricted to the Cr present as contaminant in TPN formulas. Reported here are the results of analyses of Cr concen-

and frozen (-70°C) solutions of amino acids or of lipids. Working standards of Cr were prepared by serial dilution to contain 2 and 3 ppb (ug/liter) from a reference solution of 1,000 ppm (Fisher Scientific Company, Chemical Manufacturing Division, Fair Lawn, NJ). Analysis of Cr was performed using a Perkin-Elmer 5000 Atomic Absorption Spectrophotometer fitted with graphite furnace, model 500 with Zeeman background correction with Maximum Power Temperature Sensor, Auto Sampler Model 40, Recorder Model 56 and Printer Model 10 or with Perkin-Elmer 5100 Zeeman Graphite Furnace. Pyrolytically coated tubes (Perkin-Elmer cat. no. 109322) were used with a pyrolytic platform (PerkinElmer cat. no. 290-23111). Cr absorption was measured at 357.8 nm, using a hollow cathode Cr lamp, and slit width 0.7 nm. The sample drying temperature was 120°C, char temperature 1560°C, and atomizing temperature 2400°C The sample volume was 15 ~1, and 7 Al of aqueous magnesium nitrate (0.05 mg) was added to the graphite tube as matrix modifier. Argon flow rate was reduced to 10 ml/min during the 5-sec atomizing step, during which integrated peak area absorption was measured. Measurements were taken twice for each specimen and the mean concentrations are reported. When the coefficient of variation was more than 20% between two readings, measurements were repeated. Measurements were also performed with and without the addition of a known amount of chromium to at least one representative solution of the same type to obtain a working standard curve and hence control for possible interferences. The zen

trations

by flameless atomic absorption spectrometry in large number of component solutions and of seven complete TPN formulas as prepared for administration to patients. a

MATERIALS AND METHODS

Basic solutions and additives commonly used for makwere sampled, including different lot numbers from various manufacturers. When samples from two different lots were not available, two different vials (bottles) with the same lot number were used. Samples were taken of mixed TPN solutions prepared in plastic TPN bags (Viaflex container, Travanol or Lifecare flexible container, Abbott Laboratories). Plastic pipettes (Falcon plastics, Oxnard, CA) and plastic polyethylene tubes (CS-500 Falcon, Cockeysville, MD) were used for dilutions of samples with distilled deionized water (Millipore Corp. Bedford, MA). Dilutions were prepared such that spectrophotometric readings were in the linear

ing TPN formulas

minimum absolute amount of Cr measured with acceptable accuracy was 4 pg contained in 20 Al of an 0.2 ~g/ liter solution. RESULTS

Reprints to: Dr. Nancy Alcock, Department of Preventive Medicine and Community Health, Division of Human Nutrition, University of Texas Medical Branch J09, 700 the Strand, Galveston, TX 77550. 610

Concentrations of Cr found in basic solutions and additives are summarized in Tables II and III. The concentrations of Cr in sterile water, sodium chloride, and glucose solutions with exception of a 70% glucose solu-

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611 were too low to be reliably measured (g/ml I Zinc, 1 mg, manganese 25 ~g, copper 0.1 mg, chromium 1 >g/ml

by label. by label.

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613 TABLE IV Estimated minimum and maximum contaminating Cr (Aglday) to be administered unintentionally in stable adult patients on a

likely high

glucose formula**

..........&dquo;’_....L.’-’...L’V

-......-

* On the basis of data given in Table II and III. t This formula provides approximately 2500 kcal with an energy contribution of glucose, amino acid and lipid of 70, 12, and 18%,

respectively. $ As glucose monohydrate. § When Freamine III is used as an amino acid source. When amino acids without added electrolytes are used, the maximum Cr from this is 1.7 jug for 75 g. 1f Calculated as potassium phosphate providing 15 mmol (450 mg) phosphorus and 22 mEq potassium with KCl providing remaining 48 mEq potassium. If Freamin III is used as a source of amino acids, 750 ml provides 7.5 mmol (233 mg) of phosphorus. Accordingly less K phosphate is required to provide 15 mmol phosphate, resulting in less contaminating Cr from this source. 11 CaCl2 preparation provides up to 1.27 Ag of Cr for 14.0 mEq (281 mg) of calcium. source

TABLE V Calculated and measured Cr contents

in TPN formulas

(yg)

-~ ~ ~ *

Based upon measured values of purified CrCl3. t Calculated based upon mean concentrations in components in Table II and III. $ Pediatric formulas. § This formula contained reduced amino acids and no phosphates to be administered to a patient with renal failure. intended dose 15.0 gg. II Intended dose 2.0 ~cg. &dquo;

additives. When lipid emulsion is used in large quantity, this also provides substantial amount of Cr. There were lot to lot and manufacture to manufacture variations. However, the overall trend was similar. When contaminating Cr is estimated using a standard formula (Table IV), these three sources of nutrients were calculated to provide at most up to 7.0 pg of Cr daily; this amount

accounted for 86% of the estimated maximum total Cr contamination of 8.1 j1g/day for the high glucose formula. In the high lipid formula, the maximum amounts of Cr from these three sources totaled 9.5 j1g, which was 90% of 10.5 j1g with total TPN solution. These amounts approach or equal the minimum dose of the range (1015 j1g/day) suggested for stable adult patients by an AMA expert panel.’ Foreign sources of amino acid preparations had very variable amounts of Cr varying from

Chromium content of total parenteral nutrition solutions.

Chromium (Cr) present as contaminant was analyzed by flameless atomic absorption spectrometry in a variety of commercially produced solutions and addi...
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