GENCHEM ELECTROLYTE BUFFER

K040977 · Genchem, Inc. · JGS · Dec 27, 2004 · Clinical Chemistry

Device Facts

• Record ID: K040977
• Device Name: GENCHEM ELECTROLYTE BUFFER
• Applicant: Genchem, Inc.
• Product Code: JGS · Clinical Chemistry
• Decision Date: Dec 27, 2004
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 862.1665
• Device Class: Class 2

Intended Use

GenChem ISE Electrolyte Buffer, when used in conjunction with the GenChem ISE Electrolyte Reference, GenChem CO2 Acid Reagent, GenChem CO2 Alkaline Buffer, GenChem Wash Concentrate, and appropriate Calibrators or Calibration Standards, is intended for the quantitative determination of sodium, potassium, chloride, and total CO2 in serum and plasma, and sodium, potassium and chloride in urine, and Reference will also determine calcium in serum, plasma and urine. Sodium results are for the diagnosis and treatment of aldosteronism (excessive secretion of the hormone aldosterone), diabetes insipidus (chronic excretion of large amounts of dilute urine, accompanied by extreme thirst), adrenal hypertension, Addison's disease (caused by the destruction of the adrenal glands), dehvdration, inappropriate antidiuretic hormone secretion, or other diseases involving electrolyte imbalance. Potassium results are used to monitor electrolyte imbalance in the diagnosis and treatment of diseases and conditions characterized by low or high blood potassium levels. Chloride results are used in the treatment of electrolyte and metabolic disorders such as cystic fibrosis and diabetic acidosis. Carbon dioxide results are used in the diagnosis and treatment of numerous and potentially serious disorders associated with changes in the body's acid-base balance. Calcium results are used in the diagnosis and treatment of parathyroid diseases, chronic renal disease and tetany (intermittent muscular contractions or spasm).

Device Story

The GenChem ISE Electrolyte Buffer Kit is a liquid reagent system used on the Beckman SYNCHRON CX3 clinical chemistry analyzer. It facilitates the quantitative measurement of electrolytes (Na, K, Cl, CO2, Ca) in biological fluids (serum, plasma, urine, CSF). The device operates via Ion Specific Electrodes (ISE); samples are mixed with high ionic strength buffer to stabilize activity coefficients. For CO2, a secondary reaction with acid reagent converts bicarbonate to CO2 gas, which diffuses through a silicone membrane to alter the pH of an alkaline buffer; the rate of pH change is proportional to total CO2 concentration. The system is intended for use by laboratory professionals in clinical settings. Results are used by clinicians to diagnose and manage electrolyte imbalances, acid-base disorders, and endocrine conditions. The kit provides standardized, automated analysis, enabling rapid clinical decision-making regarding patient hydration, metabolic status, and renal function.

Clinical Evidence

Bench testing only. Precision/reproducibility evaluated per NCCLS EP5-A (N=60). Linearity evaluated per NCCLS EP6-A using Least Squares method (R2=1.000 for all analytes). Analytical specificity evaluated per NCCLS EP7-A; no interference observed from hemoglobin (500 mg/dL), bilirubin (20 mg/dL), or lipemia (1800 mg/dL). Method comparison study performed on 80 adult patient samples (serum, plasma, urine, CSF) comparing GenChem reagents to Beckman reagents via least squares linear regression; results showed high correlation (r=0.935–1.000).

Technological Characteristics

Liquid reagent (Tris-Phosphate 1.5 M). Sensing principle: Potentiometric Ion Specific Electrodes (ISE) and pCO2 electrode. Dimensions/form factor: Kit components for use on Beckman SYNCHRON CX3 analyzer. Storage: Room temperature. Analytical method: Nernst equation-based potential measurement.

Indications for Use

Indicated for quantitative determination of Sodium, Potassium, Chloride, Total CO2, and Calcium in serum, plasma, urine, and CSF (Chloride only) for patients requiring electrolyte balance monitoring or diagnosis of metabolic/endocrine disorders (e.g., aldosteronism, diabetes insipidus, cystic fibrosis, parathyroid disease).

Regulatory Classification

Identification

A sodium test system is a device intended to measure sodium in serum, plasma, and urine. Measurements obtained by this device are used in the diagnosis and treatment of aldosteronism (excessive secretion of the hormone aldosterone), diabetes insipidus (chronic excretion of large amounts of dilute urine, accompanied by extreme thirst), adrenal hypertension, Addison's disease (caused by destruction of the adrenal glands), dehydration, inappropriate antidiuretic hormone secretion, or other diseases involving electrolyte imbalance.

Predicate Devices

• Electrode, Ion Specific, Sodium, Potassium, Chloride, CO2, Calcium (K801896)

Submission Summary (Full Text)

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DEC 27 2004

# 510(k) SUMMARY K040977

### 1.0 Submitted By:

C.C. Allain, Ph.D. Chief Scientific Officer GenChem, Inc. 471 W. Lambert Road, Ste 107 Brea, CA 92821 Telephone: [phone] FAX: [phone]

#### 2.0 Date of Preparation: June 1, 2004

### 3.0 Regulatory Information:

- 3.1 Regulation section: GenChem Electrolyte Buffer 21 CFR § 862.1665 Electrode, Ion Specific, Sodium, Potassium, Chloride, CO2, Calcium
- 3.2 Clasification : Class II
- 3.3 Product Code: JGS
- 3.4 Panel: Clinical Chemistry (75)

#### 4.0 Device Description:

Sodium, Potassium, Chloride, CO2 and Calcium are determined by the use of Ion Specific Electrodes, the conductivity of which is proportional to the concentration of electrolyte in the sample which is mixed with high ionic strength buffer using the ISE Solution as the reference.

- 5.0 a. Predicate Device Name: Electrode, Ion Specific, Sodium, Potassium, Chloride, CO2, Calcium
- b. Predicate K Number: K801896
- c. Comparison with Predicate: Both Reagents are similar in design, function and chemical principle as well as ingredient composition and concentration.
- 6.0 Performance Characteristics: All studies were performed on the Beckman CX3® Synchron Analyzer
- 6.1 Precision/Reproducibility: Within-Day and Day-to-Day precision was determined according to NCCLS EP5-A. Results are summarized below:

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## Within-Day; N=60

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Day-To-Day (30 Days); N=60

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### 6.2 Linearity/assay reportable range:

Linearity was performed according to NCCLS Guideline EP6-A. Commercially available linearity standards were analyzed in triplicate on the Beckman CX3® and the results analyzed by the Least Squares method. The results are shown below. Specimens exceeding these limits should be diluted with normal saline and reanalyzed. Multiply the result by the appropriate dilution factor.

| | Intercept | Slope | R2 | Sey | Range |
|---------|-----------|-------|-------|------|-------------------|
| Calcium | 0.34 | 0.911 | 1.000 | 0.35 | 0.8 – 14.3 mg/dL |
| Na | 2.37 | 0.968 | 1.000 | 2.61 | 0 – 200 mmol/L |
| K | -0.09 | 1.017 | 1.000 | 0.03 | 0.9 – 15.2 mmol/L |
| CL | -0.71 | 0.999 | 1.000 | 0.99 | 0 – 197 mmol/L |
| CO2 | 0.15 | 1.000 | 1.000 | 0.41 | 0 – 40 mmol/L |

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The results show this method is linear as shown below:

| Calcium | 0.8 to 14.3 mg/dl |
|-----------|--------------------|
| Chloride | 0 to 150 mmol/L |
| Potassium | 0.9 to 15.2 mmol/L |
| Sodium | 0 to 200 mmol/L |
| Total CO2 | 0 to 40 mmol/L |

#### 6.3 SENSITIVITY:

The sensitivity of this methodology was documented through the repetitive assay of a serum control first with a known concentration and then diluting the sample until the minimum result was obtained and then run in replicates of 10 on the Beckman Synchron® System. Under the conditions described, the following limits of detection were established:

| Analyte | Limit of Detection |
|-----------|--------------------|
| Calcium | 1.5 mg/dL |
| Sodium | 10 mmol/L |
| Potassium | 1.0 mmol/L |
| Chloride | 15 mmol/L |
| Total CO2 | 5.0 mmol/L |

- 6.4 Analytical Specificity:
Determined according to NCCLS EP7-A. Hemoglobin levels up to 500 mg/dL, Bilirubin levels up to 20 mg/dL, and Lipemia levels up to 1800 mg/dL were tested and did not show any adverse effect on a stock sample with levels of sodium at 148 mmol/L, potassium at 5.2 mmol/L, chloride at 119 mmol/L, CO2 at 19 mmol/L, and calcium at 9.4 mg/dL. Stock solutions of the substance to be tested were prepared at 20x concentrations and 0.5 ml of this stock was placed in a 10 ml volumetric flask and made up to volume with the base pool. The control stock was prepared similarly but with water as the diluent. Only Sodium Heparin, Lithium Heparin and Ammonium Heparin up to 45 Units/mL are acceptable anticoagulants.

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### 7.0 PATIENT COMPARISON :

Serum, plasma, cerebrospinal fluid and urine specimens, collected from adult patients, were assayed for calcium, chloride, potassium, sodium, and total CO2 on a SYNCHRON CX3® System using GenChem and Beckman flow cell reagents, wash solutions and calibrators. Results were compared by least squares linear regression where X = Beckman Results and Y = GenChem Results.

| Analyte Specimen | Unit | n | m | b | r | range |
|------------------|--------|----|-------|------|-------|----------|
| Calcium | | | | | | |
| Serum | mg/dL | 80 | 0.989 | 0.0 | 0.985 | 7.1-10.6 |
| Plasma | mg/dL | 80 | 0.990 | 0.0 | 0.995 | 7.1-10.7 |
| Urine | mg/dL | 74 | 1.007 | -0.2 | 0.998 | 2.4-15.2 |
| Chloride | | | | | | |
| Serum | mmol/L | 80 | 0.988 | 1.0 | 0.935 | 98 - 127 |
| Plasma | mmol/L | 80 | 0.998 | 0.8 | 0.985 | 98 - 127 |
| Urine | mmol/L | 78 | 1.049 | -5.1 | 0.999 | 22-289 |
| CSF | mmol/L | 44 | 1.024 | -3.4 | 0.985 | 113-152 |
| Potassium | | | | | | |
| Serum | mmol/L | 80 | 0.969 | 0.13 | 1.000 | 3.2-10.8 |
| Plasma | mmol/L | 80 | 0.987 | 0.15 | 1.000 | 3.2-10.8 |
| Urine | mmol/L | 80 | 0.993 | 0.01 | 1.000 | 3.5-136 |
| Sodium | | | | | | |
| Serum | mmol/L | 80 | 0.930 | 9.1 | 0.938 | 132-159 |
| Urine | mmol/L | 78 | 1.000 | -0.3 | 1.000 | 17-288 |
| Total CO2 | | | | | | |
| Serum | mmol/L | 80 | 0.949 | 1.2 | 0.953 | 9.5-29 |
| Plasma | mmol/L | 80 | 0.965 | 0.9 | 0.960 | 9.5-29 |

### 8.0 Expected Values/ Reference Range:

The expected values for calcium, chloride, potassium, sodium, and total CO2 are listed below. Use these ranges only as guides. Each laboratory should establish its own reference ranges.

Reference Ranges1

| Analyte | Specimen | Conventional Units | SI Units |
|-----------|--------------|--------------------|--------------------|
| Calcium | Serum/Plasma | 8.4 - 10.2 mg/dL | 2.10 - 2.55 mmol/L |
| | Urine | 100 - 300 mg/day | 2.5 - 7.5 mmol/day |
| Chloride | Serum/Plasma | 101 - 111 mmol/L | same |
| | Urine | 110 - 250 mmol/day | same |
| | CSF | 118 - 132 mmol/L | same |
| Potassium | Serum/Plasma | 3.5 - 5.1 mmol/L | same |
| | Urine | 25 - 125 mmol/day | same |
| Sodium | Serum/Plasma | 136 - 145 mmol/L | same |
| | Urine | 40 - 220 mmol/day | same |
| Total CO2 | Serum/Plasma | 22 - 28 mmol/L | same |

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Image /page/4/Picture/1 description: The image shows the seal of the U.S. Department of Health and Human Services. The seal features an abstract eagle design with three stylized wing segments. The words "DEPARTMENT OF HEALTH & HUMAN SERVICES • USA" are arranged in a circular pattern around the eagle. The seal is black and white.

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

DEC 27 2004

C.C. Allain. Ph.D. Chief Scientific Officer GenChem, Inc. 471 W. Lambert Road, Suite 107 Brea, CA 92821

k040977 Re:

> Trade/Device Name: GenChem ISE Electrolyte Buffer Regulation Number: 21 CFR 862.1665 Regulation Name: Sodium test system Regulatory Class: Class II Product Code: JGS, CEM, CGZ, JFL, JFP Dated: October 15, 2004 Received: October 15, 2004

Dear Dr. Allain:

We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA), You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to such additional controls. Existing major regulations affecting your device can be found in Title 21, Code of Federal Regulations (CFR), Parts 800 to 895. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Parts 801 and 809); and good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820).

{5}------------------------------------------------

Page 2 -

This letter will allow you to begin marketing your device as described in your Section 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.

If you desire specific information about the application of labeling requirements to your device, or questions on the promotion and advertising of your device, please contact the Office of In Vitro Diagnostic Device Evaluation and Safety at [phone]. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97), You may obtain other general information on your responsibilities under the Act from the Division of Small Manufacturers, International and Consumer Assistance at its toll-free number [phone] or [phone] or at its Internet address http://www.fda.gov/cdrh/dsma/dsmamain.html.

Sincerely yours,

Sincerely yours,

Cornelia B. Parks

Cornelia B. Rooks, MA Acting Director Division of Chemistry and Toxicology Office of In Vitro Diagnostic Device Evaluation and Safety Center for Devices and Radiological Health

Enclosure

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## INDICATIONS FOR USE

510(k) Number: K040977

### Device Name: GenChem ISE Electrolyte Buffer

Indications For Use:

GenChem ISE Electrolyte Buffer, when used in conjunction with the GenChem ISE Electrolyte Reference, GenChem CO2 Acid Reagent, GenChem CO2 Alkaline Buffer, GenChem Wash Concentrate, and appropriate Calibrators or Calibration Standards, is intended for the quantitative determination of sodium, potassium, chloride, and total CO2 in serum and plasma, and sodium, potassium and chloride in urine, and Reference will also determine calcium in serum, plasma and urine.

Sodium results are for the diagnosis and treatment of aldosteronism (excessive secretion of the hormone aldosterone), diabetes insipidus (chronic excretion of large amounts of dilute urine, accompanied by extreme thirst), adrenal hypertension, Addison's disease (caused by the destruction of the adrenal glands), dehvdration, inappropriate antidiuretic hormone secretion, or other diseases involving electrolyte imbalance. Potassium results are used to monitor electrolyte imbalance in the diagnosis and treatment of diseases and conditions characterized by low or high blood potassium levels. Chloride results are used in the treatment of electrolyte and metabolic disorders such as cystic fibrosis and diabetic acidosis. Carbon dioxide results are used in the diagnosis and treatment of numerous and potentially serious disorders associated with changes in the body's acid-base balance. Calcium results are used in the diagnosis and treatment of parathyroid diseases, chronic renal disease and tetany (intermittent muscular contractions or spasm).

A.berto C
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